Tuesday, 13 February 2018 16:39

Erica Eggleton

Summer Scholar Erica Eggleton joins Van Vliet Lab to make and test lithium manganese oxide electrodes.
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Graduate student Frank McGrogan, left, is supervising the work of Summer Scholar Erica Eggleton on LMO electrodes for lithium ion batteries in the Van Vliet Lab. Photo, Denis Paiste, Materials Processing Center.

After studying fuel cells at Montana State University, Erica Eggleton knew she wanted to do some type of research this summer, either with a college or in industry. “I’ve always been really interested in renewable energy, and in my lab at Montana State, I study PEM [proton exchange membrane] fuel cells, so I wanted to stay in that realm of research,” she says.

Her quest brought Eggleton, who just finished her junior year, to MIT as a 2016 MPC-CMSE Summer Scholar, where she is working in the Van Vliet Lab on lithium manganese oxide [LMO] electrodes for lithium ion batteries. Materials science and engineering graduate student Frank McGrogan is supervising her work.

This year’s 11 Summer Scholars spent their first three days in the internship program hearing project pitches from faculty, postdocs and graduate students and touring their labs. “I definitely wanted to expand my knowledge on electrochemical-based processes and there were a couple of projects that were in that field. Then I looked more at the principal investigators [PIs] and talked to the grad students during the lab tours and this one definitely seemed like a good fit, community-wise. Also, I thought it would be beneficial for me to learn about the topic from more of a materials science standpoint, because I’m starting to question, if I want to go more into materials science in grad school or whether I’m actually more interested in chemical-based processes like now,” Eggleton says.

Lab head Krystyn Van Vliet, who holds MIT faculty appointments in both biological engineering and materials science and engineering, says, “From my perspective, REU [Research Experience for Undergraduates] students such as Erica bring great enthusiasm to our lab during the Summer Scholar research period. They provide a valuable mentoring opportunity to our graduate students who realize anew the excitement and potential of their challenging, multi-year research projects, and the REUs themselves contribute unique perspectives on how to solve lab challenges.

“I have had several REU students contribute so much to a project in the two months they were here that they were co-authors on publications, and the impressive career trajectories of those REUs who worked in my lab – ranging from young faculty to medical school to graduate engineering research – shows that they made the most of the REU opportunity at MIT,” Van Vliet adds.

Eggleton is studying the type of fatigue that makes lithium ion batteries less efficient over time. “We’re studying whether this is based off of certain stresses, cracking or fractures and how that’s affecting the overall efficiency of the battery. I know I’m going to be working on making different types of electrodes and then I will look at them using SEM [scanning electron microscopy] to analyze the film properties,” Eggleton says.

Working with McGrogan, Eggleton did indentation hardness testing and cracking tests in one of her first days on the job as an intern. She’ll be making electrodes and studying the materials with analytical techniques such as SEM.

McGrogan, in his first summer working with an undergraduate, says, “Working with my REU (Erica) has refreshed my perspective on my research, as she brings a new curiosity to the problems I'm trying to solve. Erica has met my research questions with eyes wide open, and I find her ambition and enthusiasm to be personally motivating. I feel certain that she will be an important contributor to my research projects by the end of the summer.”

MPC‬‬‬‬‬‪ and CMSE sponsor the nine-week National Science Foundation Research Experience for Undergraduates (NSF REU) internships with support from NSF’s Materials Research Science and Engineering Centers program (grant number DMR-14-19807).‬ The program runs from June 7 through Aug. 6, 2016.‬‬‬‬‬

Denis Paiste, Materials Processing Center
June 29, 2016

 

 

Tuesday, 13 February 2018 15:22

Victoria Yao

Summer Scholar Victoria Yao experiments with water-based, flow-driven battery concept in Brushett Lab.

Summer Scholar Victoria Yao 2 MEA Web
MPC-CMSE Summer Scholar Victoria Yao shows a mixture of sodium thiosulfate being stirred in a solution of copper hexacyanoferrate where its reacts to produce larger compounds that can be filtered out of the solution. These compounds are being developed for use in electrodes for a water-based flow-driven battery for grid level storage. Photo, Maria E. Aglietti, Materials Processing Center.

A convection oven cooks more uniformly because a fan creates a steady flow of hot air around the food being cooked. MIT’s St. Laurent Career Development Professor of Chemical Engineering, Fikile R. Brushett, is applying that principle to a new water-based battery design that pumps a steady flow of charge-carrying ions through a battery to create a more uniform distribution of ions in the cell.

“We’re fabricating an aqueous [water-based] battery which is safe, cheap and scalable,” MPC-CMSE Summer Scholar Victoria Yao explains. A rising junior at Vanderbilt University, Yao is majoring in chemical engineering. This summer, she worked with graduate student Thomas J. Carney to develop a convection cell battery, in which electrolyte would flow through the electrode material, rather than remain static as in a conventional battery.

During her summer internship in the Brushett Research Group, Yao synthesized electrode materials in the same chemical family as Prussian blue, which is commonly used to dye fabric and to color makeup such as eye shadow. Prussian blue is the common name for ferric ferrocyanide, but unlike some highly poisonous cyanide compounds, Prussian blue is considered non-toxic and is even ingested to treat radiation poisoning.

Yao created the Prussian blue-like materials in a liquid solution of metal nitrates, adding potassium hexacyanoferrate to precipitate the desired compounds, such as copper hexacyanoferrate. Sodium thiosulfate is added to make the particles bigger and change the amount of energy stored in the material. She then separated out the particles with a filter or centrifuge. Once dried, the colorful particles were mixed with additives to make “inks” that can be precisely dripped on carbon paper to form thin electrodes for battery testing. “Immediately after you make the ink, you need to pipette it onto carbon paper, let it dry, and then remove any contaminants under vacuum,” Yao says.

These thin electrode cells were tested in a flow-through reactor – an arrangement of glass components in an “H” configuration – that runs for hours at a time, sometimes overnight, to gather sufficient data to measure their capacity and efficiency. The carbon-paper electrodes are placed in the upright glass tubes with a sodium chloride [table salt] solution connecting the two through the middle. After adding a reference electrode, Yao bubbled argon gas through the experimental setup.

“I’ve made eight different powders, and tested their energy storage properties with thin electrodes,” she says.

After making and testing thin electrodes, Yao plans to move to producing thick porous electrodes, which could yield higher energy density. These thick electrodes require more raw material, which is compressed into pellets.

In presenting this project, which he calls Convection Enhanced Electrochemical Energy Storage, to Summer Scholars in June, Brushett said, “We’ve got a proof of concept, and we’re really excited. ... Ideally we’d like to translate this proof-of-concept device into a little canister-like flow cell with thick porous electrodes and pump electrolyte through the reactor... and there we should have our convection battery.”

Summer Scholar Victoria Yao 1 MEA Web
MPC-CMSE Summer Scholar Victoria Yao holds a container with a thin electrode made of carbon with a copper hexacyanoferrate [Prussian blue] type active area at the top end. Photo, Maria E. Aglietti, Materials Processing Center

“Prussian blue-related chemical compounds have an open framework that allows ions to move in and out of the two battery electrodes while remaining solvated (bound to water molecules) by the electrolyte solution which, in turn, enables fast reactions. When coupled with a flowing electrolyte we may be able to develop energy dense batteries with thick electrodes and tunable power output,” Brushett says. The project fits into the Brushett lab’s larger goal of helping to build a sustainable energy economy through innovative, new energy storage technologies.

“Victoria has been instrumental in synthesizing and characterizing Prussian blue analogue materials for use in convection-based energy storage devices this summer. The MPC-CMSE Summer Scholar’s program provides opportunities for talented undergraduates from across the country to work on cutting-edge research projects here at MIT,” Brushett says. “Not only do these students learn of the discipline, tenacity, and creativity required to perform fundamental research but our graduate students learn how to mentor enthusiastic but less experienced lab workers. Her dedication and aptitude have directly accelerated our research! We are very happy to have hosted her this summer.”

‪MPC‬‬‬‬‬‪‬‬‬‬‬‬‬‬‬‬‬‬ and ‪CMSE‬‬‬‬‬‬ sponsor the nine-week National Science Foundation Research Experience for Undergraduates (NSF REU) internships with support from ‪NSF‬‬‬‬‬‬’s Materials Research Science and Engineering Centers program (grant number DMR-14-19807).‬ The program runs from June 7 through Aug. 6, 2016.‬‬‬‬‬ ‬‬‬‬ 

 

Denis Paiste, Materials Processing Center | Aug. 22, 2016

 Related: Going with the Flow Battery

Tuesday, 13 February 2018 15:11

Ashley Kaiser

Summer Scholar Ashley Kaiser delves into hybrid carbon nanotube materials research in nectslab.

Ashley Kaiser 6 MEA Web
Ashley Kaiser holds samples of carbon nanotubes she grew in the Wardle lab as part of her summer project studying carbon nanotube-based aligned nanofiber carbon matrix nanocomposites [CNT A-CMNCs]. The carbon nanotubes are on the left, and the pyrolytic carbon is on the right. These new materials have potential aerospace applications. Photo, Maria E. Aglietti.

University of Massachusetts Amherst chemical engineering major Ashley Kaiser joined MIT Professor of Aeronautics and Astronautics Brian L. Wardle's necstlab this summer with past experience in growing graphene and examining it with Raman spectroscopy.

During her new summer internship, Kaiser, who is a rising senior, is learning new fabrication and characterization techniques to further necstlab’s research on carbon nanotube aligned nanofiber carbon matrix nanocomposites [CNT A-CMNCs].

High temperature composites

MPC-CMSE Summer Scholar Kaiser is making these composites, which are treated at high temperatures from 600 to 1400 Celsius [1112 F to 2552 F], and analyzing their composition to study the confinement effects of the carbon nanotubes in the carbon matrix. Similar heat-treated material, called pyrolytic carbon [PyC], is currently used for aerospace applications but in a simpler form without embedded carbon nanotubes. “It’s super hard and lightweight, and since carbon nanotubes are also very strong and lightweight as well, we would like to introduce these nanotubes inside this existing matrix,” Kaiser explains.

“Ashley’s primary contribution is to help us understand how the aligned carbon nanotubes facilitate the self-organization and meso-scale evolution of the graphitic crystallites that comprise the pyrolytic carbons, and how control over the processing (i.e., pyrolysis) temperature can modify the structure and morphology of A-CNT-PyC hybrid nanocomposite materials on the nanoscale,” necstlab Postdoctoral Associate Itai Stein says.

“The results from Ashley’s project will be invaluable to better understanding the process-structure-property relations of these high temperature materials,” Stein adds. Kaiser’s project builds on work done in necstlab by 2015 MPC-CMSE Summer Intern Alexander Constable, who studied the structural evolution of pyrolytic carbon (PyC) as a function of processing parameters and the effects of aligned carbon nanotube (A-CNT) confinement.

Four key steps

Her project consists of four steps, Kaiser explains:

• Carbon nanotube growth
• Polymer resin infusion
• Oven curing the polymer matrix nanocomposites
• High temperature heat treatment (pyrolysis)

“Basically, we want to fabricate and characterize the composites to see what effect the carbon nanotubes are having on the final structure to address several questions – what it looks like, if the nanotubes stay aligned, are there functional groups inside of that, are there defects, what’s the crystallite size, etc.” Kaiser says.

“We are seeing that when we are putting our nanotubes into our composite, the effect of them governs the meso-scale [submicron scale], which means that the way the atoms are arranging in our crystallites isn’t changing too much just from having our nanotubes there, which is interesting. So in terms of scaling this up to, say, something in industry, the fact that it’s not changing the entire atomic scale is beneficial because it means that processing may not be too different,” she says.

“This composite is a closely-related material with similar strength to PyC because the atoms are arranged similarly, but it’s more lightweight, at least we think, which is a step up in improving the current technology,” she adds.

Adding new skills

Although she previously grew graphene using chemical vapor deposition, growing the carbon nanotubes using a similar chemical vapor deposition process at MIT and making the final nanocomposites requires more steps. “After the CNT growth, I do polymer infusion under vacuum, then the samples are cured in an oven, and then they are pyrolyzed in an even larger furnace. In this way, I’m working on many different pieces of equipment in the lab, which is great experimental experience,” Kaiser says.

Ashley Kaiser 3 MEA Web
Ashley Kaiser prepares to grow carbon nanotubes [CNTs] on a silicon wafer with a coating of alumina and iron in a 1-inch furnace. Alumina and iron act as catalysts to stimulate the CNTs to grow. During her summer project in the Wardle lab, Kaiser grew pyrolytic carbon as a control in addition to growing carbon nanotubes, turning out 5 samples of each at a time. Photo, Maria E. Aglietti.

Although she has previous experience with Raman spectroscopy at UMass and from her 2015 summer internship at 3M, she is learning new characterization skills at MIT this summer, including SEM [scanning electron microscopy], FTIR [Fourier Transform Infrared Spectroscopy], XRD [X-ray Diffraction] and SAXS [Small Angle X-ray Scattering]. “I think that’s going to be really beneficial experience moving forward into graduate work,” she suggests.

Diamond-like structure

“The overarching goal is to study the impact of carbon nanotube confinement on the graphitic crystallites that comprise the pyrolytic carbon, or the matrix of our nanocomposites,” Kaiser explains. “We are finding that as our temperature is increasing, our material is evolving, and it’s forming essentially a lower density pyrolytic carbon which may be more diamond-like, and very strong. We are interested in examining how the nanotubes are affecting the carbon matrix crystallite growth in the composite at various processing temperatures. If this material can be processed to maintain high strength while becoming even lighter, it could be an ideal candidate for aerospace applications.

“I’m essentially doing all the processing, characterization and analysis on my own, so I’m really very solo on this project. I have about 50 robust samples to fabricate and analyze over the course of my summer internship here at MIT,” Kaiser explains. “I’m definitely quite busy with that, but I’m very excited about it at the same time.”

MPC‬‬‬‬‬‪‬‬‬‬ and ‪CMSE‬‬‬ sponsor the nine-week National Science Foundation Research Experience for Undergraduates (NSF REU) internships with support from ‪NSF‬‬‬’s Materials Research Science and Engineering Centers program (grant number DMR-14-19807).‬ The program runs from June 7 through Aug. 6, 2016.‬‬‬‬‬ ‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬

 

Denis Paiste, Materials Processing Center | July 27, 2016

Tuesday, 13 February 2018 14:54

Alexandra Barth

Summer Scholar Alexandra Barth analyzes carbon monoxide resistance of core-shell nanoparticle catalysts in the Román Lab.

Alexandra Barth 3 MEA Web
MPC-CMSE Summer Scholar Alexandra Barth works at a hood where she makes carbide core-platinum shell nanoparticles for electrocatalytic applications such as fuel cells and electrolyzers in the lab of MIT Associate Professor of Chemical Engineering Yuriy Román-Leshkov. The process of making core-shell nanoparticles consists of many steps and takes three to five days to complete. Photo, Maria E. Aglietti, Materials Processing Center.

In May the group of MIT Associate Professor of Chemical Engineering Yuriy Román-Leshkov published a study showing that an ultra-thin shell of platinum on a carbide core could catalyze hydrogen evolution and oxidation reactions as effectively as pure platinum at a fraction of the cost. MPC-CMSE Summer Scholar Alexandra T. Barth is helping to advance this work by studying the tunability of these core-shell materials and their performance in a number of electrocatalytic applications.

“What’s been interesting is we found even when we’re creating nanoparticles that are just coated with an atomically thin layer of platinum, they act as effectively as conventional platinum-only nanoparticle catalysts,” Barth explains.

Platinum is a key component in many traditional and emerging technologies, including automobile catalytic converters, oil reforming, fuel cells and electrolyzers. The goal of the project, Dr. Maria Milina, a postdoctoral associate in the Román group explains, is to design noble metal catalysts with significantly reduced metal loadings but improved activity and stability. “We tackle this challenge through the synthesis of core-shell nanoparticles, in which a cheap metal carbide core not only reduces the requirements for expensive platinum but also beneficially modifies its electronic properties,” says Milina.

Avoiding carbon monoxide poisoning

The research of Prof. Román shows that platinum-coated carbide nanoparticles can be used as catalysts for hydrogen evolution and hydrogen oxidation reactions that occur at the cathode of water electrolyzers and at the anode of fuel cells, respectively. Simultaneously they demonstrate remarkable resistance to carbon monoxide, a common catalyst poison. “You want to create a catalyst that will activate hydrogen even when carbon monoxide is present in fuel streams,” Barth says. Carbon monoxide is known to bind strongly to platinum and to block its ability to catalyze other reactions. “Metal carbide cores favorably modulate electronic properties of platinum through subsurface strain and ligand effect leading to the reduced carbon monoxide binding energy of platinum in a core-shell architecture,” explains Prof. Román.

Barth, a rising senior from Florida State University, is interning in the Román lab at MIT this summer. She is synthesizing core-shell nanoparticles with varying core and shell composition, examining their structure with techniques such as infrared spectroscopy and powder X-ray diffraction, and conducting electrocatalytic experiments to analyze their performance in hydrogen evolution/hydrogen oxidation reactions.

A multistep process

The process of making core-shell nanoparticles consists of many steps and takes three to five days to complete, Barth notes. “It’s interesting because the entire process was devised in this lab, so it’s like nothing that’s been done before,” she says. The process involves synthesizing the nanoparticles in a reverse microemulsion, heating the sample in a methane atmosphere to produce a carbide core, and separating the nanoparticles from their silica templates simultaneously dispersing them on a high surface area carbon support in a diluted hydrofluoric acid. The last step in the process, working with hydrofluoric acid, required special safety training.

After synthesis, Barth tests the core-shell nanoparticle catalyst in a three-electrode electrochemical cell. “We initially determine the hydrogen evolution and oxidation activity of the catalysts in a pure hydrogen atmosphere. Then we intentionally introduce carbon monoxide poison into the hydrogen stream and record how quickly catalyst deactivates and how high is the overpotential required to strip carbon monoxide from the platinum surface,” she says.

Infrared spectroscopy challenge

While characterization of solids by X-ray diffraction was a familiar skill from her work at FSU, Barth was facing a challenge with infrared spectroscopy. “We know what we’re expecting of this analysis. I firstly need to record a spectrum of a reduced in hydrogen catalyst, then I should saturate it with carbon monoxide and, after removal of physisorbed species, register another spectrum with the absorbances corresponding to platinum-carbon monoxide interactions. But the use of infrared spectroscopy for carbon-supported catalysts has been always a challenge due to the high opacity of these materials. So that’s been a work in progress,” she says.

“Back at FSU, I do radiochemistry research, so I make crystals with nuclear elements,” she explains. “This is out of my comfort zone because I’ve never done nanoparticle research before, and I’ve never done catalysis research before. But what I have realized through doing this summer project is that I could advance my current research at FSU by including new catalytic studies.” Barth is considering modifying her honors thesis to bridge radiochemistry and catalysis, taking her work from just making crystals to testing their catalytic properties.

Barth is pursuing a major in chemistry at Florida State and hopes to pursue a doctorate in inorganic chemistry.

‪MPC‬‬‬‬‬‪‬‬‬‬‬‬‬‬‬‬‬‬ and ‪CMSE‬‬‬‬‬‬ sponsor the nine-week National Science Foundation Research Experience for Undergraduates (NSF REU) internships with support from ‪NSF‬‬‬‬‬‬’s Materials Research Science and Engineering Centers program (grant number DMR-14-19807).‬ The program runs from June 7 through Aug. 6, 2016.‬‬‬‬‬ ‬‬‬‬

 – Denis Paiste, Materials Processing Center | July 27, 2016

 

Merger of the Materials Processing Center and the Center for Materials Science and Engineering melds a rich history of materials science and engineering breakthroughs.
MRL Director Carl V Thompson 9321 DP Web
MIT MRL Director Carl V. Thompson. Photo, Denis Paiste, MIT MRL.

The Materials Research Laboratory at MIT starts from a foundation of fundamental scientific research, practical engineering applications, educational outreach and shared experimental facilities laid by its merger partners, the Materials Processing Center and the Center for Materials Science and Engineering.

“We’re bringing them together and that will make communication both inside and outside MIT easier and will make it clearer especially to people outside MIT that for interdisciplinary research on materials, this is the place to learn about it,” says MRL Director Carl V. Thompson.

The Materials Research Laboratory serves interdisciplinary groups of faculty researchers, spanning the spectrum of basic scientific discovery through engineering applications and entrepreneurship to ensure that research breakthroughs have impact on society. The center engages with approximately 150 faculty members and scientists from across the Schools of Science and Engineering who are conducting materials science research. MRL will work with MIT.nano to enhance the toolset available for groundbreaking research as well as collaborate with the MIT Innovation Initiative and The Engine.

MRL will benefit from the long history of research breakthroughs under MPC and CMSE such as “perfect mirror” technology developed through CMSE in 1998 that led to a new kind of fiber optic surgery and a spinout company, OmniGuide Surgical, and the first germanium laser operating at room temperature, which is used for optical communications, in 2012 through MPC’s affiliated Microphotonics Center.

The Materials Processing Center brings to the partnership its wide diversity of materials research, funded by industry, foundations and government agencies, while the Center for Materials Science and Engineering brings its seed projects in basic science and Interdisciplinary Research Groups, educational outreach and shared experimental facilities, funded under the National Science Foundation Materials Research Science and Engineering Center program [NSF-MRSEC]. Combined research funding was $21.5 million for the fiscal year ended June 30, 2017.

MPC’s research volume more than doubled during the past nine years under Thompson’s leadership. “We do have a higher profile in the community both internal as well as external. We developed over the years a close collaboration with CMSE, including outreach. That will be greatly amplified through the merger,” he says. Thompson is the Stavros Salapatas Professor of Materials Science and Engineering at MIT.

Tackling energy problems

With industrial support, MPC and CMSE launched the Substrate Engineering Lab in 2004. MPC affiliates include the AIM Photonics Academy, the Center for Integrated Quantum Materials and the MIT Skoltech Center for Electrochemical Energy Storage. Other research includes Professor ‪Harry L. Tuller’s‬‬‬‬ Chemomechanics of Far-From-Equilibrium Interfaces (COFFEI) project, which aims to produce better oxide-based semiconductor materials for fuel cells, and ‬‬‬‬‬‬‬Senior Research Scientist Jurgen Michel’s Micro-Scale Optimized Solar-Cell Arrays with Integrated Concentration (MOSAIC) project, which aims to achieve overall efficiency of greater than 30 percent. ‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬

The MPC kicked off the Singapore-MIT Alliance for Research and Technology Center’s program in Low Energy Electronic Systems [SMART-LEES] in January 2012, managing the MIT part of the budget. SMART-LEES, led by Eugene A. Fitzgerald, the Merton C. Flemings-SMA Professor of Materials Science and Engineering at MIT, was renewed for another five years in January 2017.

Shared experimental facilities, including X-Ray diffraction, scanning and transmission electron microscopy, probe microscopy, and surface analytical capabilities, are used by more than 1,100 individuals each year. “The amount of investment that needs to be made to keep state-of-the-art shared facilities at a university like MIT is on the order of 1 to 2 million dollars per year in new investment and new tools. That kind of funding is very difficult to get. It certainly doesn’t come to us through just NSF funding,” says TDK Professor of Polymer Materials Science and Engineering Michael F. Rubner, who is retiring after 16 years as CMSE director. “MIT.nano, in concert with MRL, will be able to work together to look at new strategies for trying to maintain state-of-the-art equipment and to find funding sources and to figure out ways to not only get the equipment in, but to have highly trained professionals running that equipment.”

Associate Professor of Materials Science and Engineering Geoffrey S.D. Beach succeeds Rubner as co-director of the MIT MRL and principal investigator for the NSF-MRSEC.

Spinning out jobs

Merton Flemings Merger 8974 DP MIT MRL
Merton C. Flemings, founding director [1980-82] of MIT Materials Processing Center and retired Toyota Professor of Materials Processing. Photo, Denis Paiste, MIT MRL.

NSF-MRSEC-funded research through CMSE has led to approximately 1,100 new jobs through spinouts such as American Superconductor [superconductivity], OmniGuide Surgical [optical fibers] and QD Vision [quantum dots], which Samsung acquired in 2016. Many of these innovations began with seed funding, CMSE’s earliest stage of support, and evolved through joint efforts with MPC, such as microphotonics research that began with a seed grant in 1993, followed by Interdisciplinary Research Group funding a year later. In 1997, MIT researchers published two key papers in Nature and Physical Review Letters, won a two-year, multi-university award through DARPA for Photonic Crystal Engineering, and formed the Microphotonics Center. Further research led to the spinout in 2002 of Luminus Devices, which specializes in solid-state lighting based on light emitting diodes [LEDs].

“Our greatest legacy is bringing people together to produce fundamental new science, and then allowing those researchers to explore that new science in ways that may be beneficial to society, as well as to develop new technologies and launch companies,” Rubner says. He recalls that research in complex photonic crystal structures began with Francis Wright Davis Professor of Physics John D. Joannopoulos as leader. “They got funding through us, at first as seed funding and then IRG [interdisciplinary research group] funding, and over the years, they have continued to get funding from us because they evolved. They would seek a new direction, and one of the new directions they evolved into was this idea of making photonic fibers, so they went from photonic crystals to photonic fibers and that led to, for example, the launching of OmniGuide.” An outgrowth of basic CMSE research, the company’s founders included Professors Joannopolous, Yoel Fink, and Edwin L. [“Ned”] Thomas, who served as William and Stephanie Sick Dean of the George R. Brown School of Engineering at Rice University from 2011 to 2017.

Under Fink’s leadership, that work evolved into Advanced Functional Fabrics of America [AFFOA], a public-private Manufacturing Innovation Institute devoted to creating and bringing to market revolutionary fibers and textiles. The institute, which is a separate nonprofit organization, is led by Fink, while MIT on-campus research is led by Lammot du Pont Professor of Chemical Engineering Gregory C. Rutledge.

Susan D. Dalton, NSF-MRSEC Assistant Director, recalls the evolution of perfect mirror technology into life-saving new fiber optic surgery. “From an administrator’s point of view,” Dalton says, “it’s really exciting because day to day, things happen that you don’t know are going to happen. When you think about saving people’s lives, that’s amazing, and that’s just one example,” she says.

Government, industry partners

Through its Collegium and close partnership with the MIT‪ Industrial Liaison Program (‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬ILP), MPC has a long history of government and industrial partnerships as well as individual faculty research projects. Merton C. Flemings, who is MPC’s founding director [1980-82], and a retired Toyota Professor of Materials Processing, recalls that the early focus was primarily on metallurgy, but ceramics work also was important. “It’s gone way beyond that, and it’s a delight to see what’s going on,” he notes.‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬‬

“From the time of initiation of the MPC, we had interdepartmental participation, and quite soon after its formation, we initiated an industrial collegium to share in research formulation and participate in research partnerships. I believe our collegium was the first to work collaboratively with the Industrial Liaison Program. It was also at a period in MIT history when working directly with the commercial sector was rare,” Flemings says.

Founded in February 1980, the Materials Processing Center won early support from NASA, which was interested in processing materials in space. A question being asked then was: “What would it be like when you’re in zero gravity and you try and purify a metal or make anything out there? Dr. John R. Carruthers headed this zero gravity materials processing activity in NASA, and as he considered the problem, he realized we didn’t really have much of a science base of materials processing on earth, let alone in space. With that in mind, at Carruthers’ instigation, NASA provided a very generous continuing grant to MIT that was essential to us starting in those early years,” Flemings explains.

Carruthers went on to become director of research with Intel and is now Distinguished Professor of Physics, at Portland [Oregon] State University. The two men – Flemings at MIT and Carruthers at the University of Toronto – had been familiar with each other’s work in the study of how metals solidify, before Carruthers joined NASA as director of its materials processing in space program in 1977. Both Flemings and Carruthers wanted to understand how the effects of gravitationally driven convection influenced the segregation processes during metals solidification.

John Carruthers Merger MIT MRL
Dr. John R. Carruthers headed zero gravity materials processing activity in NASA, and provided critical early funding for MIT Materials Processing Center. Courtesy photo.

“In molten metal baths, as the metal solidifies into ingots, the solidification process is never uniform. And so the distribution of the components being solidified is very much affected by fluid flow or convection in the molten metal,” Carruthers explains. “We were both interested in what would happen if you could actually turn gravity down because most of the convective effects were influenced by density gradients in the metal due to thermal and compositional effects. So, we were quite interested in what would happen given that those density gradients existed, if you could actually turn the effects of gravity down.”

“When the NASA program came around, they wanted to try to use the low gravity environment of space to actually fabricate materials,” Carruthers recalls. “After a couple of years at NASA, I was able to secure some block grant funding for the center. It subsequently, of course, has developed its own legs and outgrown any of the initial funding that we provided, which is really great to see, and it’s a tribute to the MIT way of doing research, of course, as well. I was really quite proud to be part of the early development of the center,” Carruthers says. “Many of the things we learned in those days are relevant to other areas. I’m finding a lot of knowledge and way of doing things is transferrable to the biomedical sciences, for example, so I’ve become quiet interested in helping to develop things like nanomonitors, you know, more materials science-oriented approaches for the biomedical sciences.”

Expanding research portfolio

From its beginnings in metals processing with NASA support, MPC evolved into a multi-faceted center with diverse sponsors of research in energy harvesting, conversion and storage; fuel cells; quantum materials and spintronics; materials integration for microsystems; photonic devices and systems; materials systems and sustainability; solid-state ionics; as well as metals processing, an old topic that is hot again.

MRL-affiliated MIT condensed matter physicists include experimentalists Raymond C. Ashoori, Joseph G. Checkelsky, Nuh Gedik, and Pablo Jarillo-Herrero, who are exploring quantum materials for next-generation electronics, such as spintronics and valleytronics, new forms of nanoscale magnetism, and graphene-based optoelectronic devices. Riccardo Comin explores electronic phases in quantum materials. Theorists Liang Fu and Senthil Todadri envision new forms of random access memory, Majorana fermions for quantum computing, and unusual magnetic materials such as quantum spin liquids.

In the realm of biophysics, Associate Professor Jeff Gore tests fundamental ideas of theoretical ecology and evolutionary dynamics through experimental studies of microbial communities. Class of 1922 Career Development Assistant Professor Ibrahim Cissé uses physical techniques that visualize weak and transient biological interactions to study emergent phenomena in live cells with single molecule sensitivity. On the theoretical front, Professor Thomas D. & Virginia W. Cabot Career Development Associate Professor of Physics Jeremy England focuses on structure, function, and evolution in the sub-cellular biophysical realm.

Alan Taub, Professor of Materials Science and Engineering at the University of Michigan, has become a member of the new Materials Research Laboratory External Advisory Board. Taub previously served in senior materials science management roles with General Motors, Ford Motor Co. and General Electric and served as chairman of the Materials Processing Center Advisory Board from 2001-2006. He notes that under Director Lionel Kimerling [1993-2008], MPC embraced the new area of photonics. “That transition was really well done,” Taub says. The MRL-affiliated Microphotonics Center has produced collaborative roadmapping reports since 2007 to guide manufacturing research and address systems requirements for networks that fully exploit the power of photonics. Taub also is chief technical officer of LIFT Manufacturing Innovation Institute, in which MIT Assistant Professor of Materials Science and Engineering Elsa Olivetti and senior research scientist Randolph E. [Randy] Kirchain are engaged in cost modeling.

From its founding, Taub notes, MPC engaged the faculty with industry. Advisory board members often sponsored research as well as offering advice. “So it was really the way to guide the general direction, you know, teach them that there are things industry needs. And remember, this was the era well before entrepreneurism. It really was the interface to the Fortune 500’s and guiding and transitioning the technology out of MIT. That’s why I think it survived changes in technology focus, because at its core, it was interfacing industry needs with the research capabilities at the Institute,” Taub says.

Alan Taub Merger MIT MRL
Alan Taub, Professor of Materials Science and Engineering at the University of Michigan, has become a member of the new Materials Research Laboratory External Advisory Board. Courtesy photo.

Broadening participation

Susan Rosevear, who is the Education Officer for the NSF-MRSEC, is responsible for an extensive array of programs, including the Summer Scholars program, which is primarily funded through NSF’s Research Experience for Undergraduates (REU) program. Each summer a dozen or so top undergraduates from across the country spend about two months at MIT as lab interns working with professors, postdocs and graduate students on cutting edge research.

CMSE also conducts summer programs for community college students and teachers, middle and high school teachers, and participates in the Women’s Technology Program and Boston Area Girls' STEM Collaborative. “Because diversity is also part of our mission, part of what our mission from NSF is, in all we do, we try to broaden participation in science and engineering,” Rosevear says.

Teachers who participate in these programs often note how collaborative the research enterprise is at MIT, Rosevear notes. Several have replaced cookbook-style labs with open-ended projects that let students experience original research.

Confidence to test ideas

Merrimack [N.H.] High School chemistry teacher Sean Müller first participated in the Research Experience for Teachers program in 2000. “Through my experiences with the RET program, I have learned how to ‘run a research group’ consisting of my students. Without this experience, I would not have had the confidence to allow my students to research, develop, and test their original ideas. This has also allowed me to coach our school’s Science Olympiad team to six consecutive state titles, to mentor a set of students that developed a mini bio-diesel processor that they sold to Turner Biodiesel, and to mentor another set of students that took second place in Embedded Systems at I.S.E.F. [Intel International Science and Engineering Fair] last year for their ChemiCube chemical dispensing system,” Müller says.

Müller says he is always looking for new ideas and researching older ideas to develop lab activities in his classroom. “One year my students made light emitting thin films. We have grown beautiful bismuth crystals in our test furnace, and currently I am working out how to make glow-in-the-dark zinc sulfide electroluminescent by doping it with copper so that we can make our own electroluminescent panels,” he says. “Next year we are going to try to make the clear see-through wood that was in the news earlier this year. I am also bringing in new materials that they have not seen before such as gallium-indium eutectic. These novel materials and activities generate a very high level of enthusiasm and interest in my students, and students that are excited, interested, and motivated learn more efficiently and more effectively.”

Müller developed a relationship with Prof. Steve Leeb that has brought Müller back to MIT during past summers to present a brief background in polymer chemistry, supplemented by hands-on demonstrations and activities, for the Science Teacher Enrichment Program (STEP) and Women’s Technology program. “Last year I showed them how they could use their cell phone and a polarized film to see the different areas of crystallization in polymers when they are stressed,” Müller says. “I enjoy the presentation because it is more of a conversation with all of the teachers, myself included, asking questions about different activities and methods and discussing what has worked and what has not worked in the past.” 

Conducive environment

Looking back on his nine years as MPC director, Thompson says, “The MPC served a broad community, but many people at MIT didn’t know about it because it was in the basement of Building 12. So one of the things that I wanted to do was raise the profile of MPC so people better understood what the MPC did in order to better serve the community.” MPC rolled out a new logo and developed a higher profile Web page, for example. “I think that was successful. I think many more people understand who we are and what we do and that enables us to do more,” Thompson says. In 2014 MPC moved to Building 24 as the old Building 12 was razed to make way for MIT.nano. The new MRL is consolidating its offices in Building 13.

“Research breakthroughs by their very nature are hard to predict, but what we can do is we can create an environment that leads to research breakthroughs,” Thompson says. “The successful model in both MPC and CMSE is to bring together people interested in materials, but with different disciplinary backgrounds. We’ve done that separately, we’ll do it together, and the expectation is that we’ll do it even more effectively.”

 – Denis Paiste, Materials Research Laboratory
October 10, 2017
Updated January 25, 2018

Tuesday, 28 November 2017 16:50

Turning emissions into fuel

MIT-developed method converts carbon dioxide into useful compounds.
MIT Fuel From CO2 Wu Web
XiaoYu Wu pictured with the reactor his team used for the research. MIT researchers have developed a new system that could potentially be used for converting power plant emissions of carbon dioxide into useful fuels. The method may not only cut greenhouse emissions; it could also produce another potential revenue stream to help defray its costs. Image, Tony Pulsone

MIT researchers have developed a new system that could potentially be used for converting power plant emissions of carbon dioxide into useful fuels for cars, trucks, and planes, as well as into chemical feedstocks for a wide variety of products.

The new membrane-based system was developed by MIT postdoc Xiao-Yu Wu and Ahmed Ghoniem, the Ronald C. Crane Professor of Mechanical Engineering, and is described in a paper in the journal ChemSusChem. The membrane, made of a compound of lanthanum, calcium, and iron oxide, allows oxygen from a stream of carbon dioxide to migrate through to the other side, leaving carbon monoxide behind. Other compounds, known as mixed ionic electronic conductors, are also under consideration in their lab for use in multiple applications including oxygen and hydrogen production.

Carbon monoxide produced during this process can be used as a fuel by itself or combined with hydrogen and/or water to make many other liquid hydrocarbon fuels as well as chemicals including methanol (used as an automotive fuel), syngas, and so on. Ghoniem’s lab is exploring some of these options. This process could become part of the suite of technologies known as carbon capture, utilization, and storage, or CCUS, which if applied to electicity production could reduce the impact of fossil fuel use on global warming.

The membrane, with a structure known as perovskite, is “100 percent selective for oxygen,” allowing only those atoms to pass, Wu explains. The separation is driven by temperatures of up to 990 degrees Celsius, and the key to making the process work is to keep the oxygen that separates from carbon dioxide flowing through the membrane until it reaches the other side. This could be done by creating a vacuum on side of the membrane opposite the carbon dioxide stream, but that would require a lot of energy to maintain.

In place of a vacuum, the researchers use a stream of fuel such as hydrogen or methane. These materials are so readily oxidized that they will actually draw the oxygen atoms through the membrane without requiring a pressure difference. The membrane also prevents the oxygen from migrating back and recombining with the carbon monoxide, to form carbon dioxide all over again. Ultimately, and depending on the application, a combination of some vaccum and some fuel can be used to reduce the energy required to drive the process and produce a useful product.

The energy input needed to keep the process going, Wu says, is heat, which could be provided by solar energy or by waste heat, some of which could come from the power plant itself and some from other sources. Essentially, the process makes it possible to store that heat in chemical form, for use whenever it’s needed. Chemical energy storage has very high energy density — the amount of energy stored for a given weight of material — as compared to many other storage forms.

At this point, Wu says, he and Ghoniem have demonstrated that the process works. Ongoing research is examining how to increase the oxygen flow rates across the membrane, perhaps by changing the material used to build the membrane, changing the geometry of the surfaces, or adding catalyst materials on the surfaces. The researchers are also working on integrating the membrane into working reactors and coupling the reactor with the fuel production system. They are examining how this method could be scaled up and how it compares to other approaches to capturing and converting carbon dioxide emissions, in terms of both costs and effects on overall power plant operations.

In a natural gas power plant that Ghoniem’s group and others have worked on previously, Wu says the incoming natural gas could be split into two streams, one that would be burned to generate electricity while producing a pure stream of carbon dioxide, while the other stream would go to the fuel side of the new membrane system, providing the oxygen-reacting fuel source. That stream would produce a second output from the plant, a mixture of hydrogen and carbon monoxide known as syngas, which is a widely used industrial fuel and feedstock. The syngas can also be added to the existing natural gas distribution network.

The method may thus not only cut greenhouse emissions; it could also produce another potential revenue stream to help defray its costs.

The process can work with any level of carbon dioxide concentration, Wu says — they have tested it all the way from 2 percent to 99 percent — but the higher the concentration, the more efficient the process is. So, it is well-suited to the concentrated output stream from conventional fossil-fuel-burning power plants or those designed for carbon capture such as oxy-combustion plants.

“It is important to use carbon dioxide to produce carbon monoxide for the conversion of sustainable thermal energies to chemical energy,” says Xuefeng Zhu, a professor of chemical physics at the Chinese Academy of Sciences, in Dalian, China, who was not involved in this work. “Using an oxygen-permeable membrane can significantly reduce the reaction temperature, from 1,500 C to less than 1,000 C, indicating a great energy saving compared to the traditional carbon dioxide decomposition process,” he says. “I think their work is important to the field of sustainable energy and membrane processes.”

The research was funded by Shell Oil and the King Abdullah University of Science and Technology.

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David L. Chandler | MIT News Office
November 28, 2017

Materials Day 2017

Bringing together researchers from different science and engineering fields promises solutions to global needs in energy, health and quality of life.

Interdisciplinary materials research holds the key to solving the existential challenges facing humanity, former Sandia National Laboratories executive Julia M. Phillips told the annual MIT Materials Research Laboratory [MRL] Materials Day Symposium on Wednesday, Oct. 11, 2017. “What is both very exciting for us as materials researchers, also a little frustrating, is that the real impact of materials occurs when they turn into something that you actually carry around in your pocket or whatever,” Phillips said.

During the second half of the 20th century, many of the technological advances that we take for granted today, such as laptop computers and smart phones, came from fundamental advances in materials research and the ability to control and make materials, she noted. Phillips, who retired from Sandia National Laboratories as Vice President and Chief Technology Officer, also serves as chair of the MRL External Advisory Board and is a member of the National Science Board.

MRL formed from the merger of the Materials Processing Center and the Center for Materials Science and Engineering, effective Oct. 1, 2017. MRL Director Carl V. Thompson noted in his introductory remarks, the appointment of Associate Professor of Materials Science and Engineering Geoffrey S.D. Beach as co-director of the MRL and principal investigator for the National Science Foundation Materials Research Science and Engineering Center.

View the embedded image gallery online at:
https://mrl.mit.edu/index.php/tag/transportation#sigProId07c8403e82

Fueled by industrial needs and government-funded research in the post-World War II era, “Materials research was undeniably an early model for interdisciplinary research,” Phillips said. With new tools such as scanning probe microscopes to understand the structure and properties of materials, materials scientists in the last half of the 20th Century created whole new classes of materials and products, ranging from super alloys that enabled larger and more reliable jet engines to strained layer superlattices that underlie modern magnetic recording,7 lasers and infrared detectors.

Future gains will come from the ability to synthesize and control increasingly complex materials, Phillips says, noting progress in areas such as high-temperature superconductors, porous solids like metal organic frameworks, and metamaterials that generate new properties from combining biological materials, organics, ceramics and metals at near molecular scale precision in ways not found in nature. “Somewhere in the fuzzy space between molecules and materials,” Phillips notes, these newer materials have very interesting properties that are still in the process of being fully explored, and they will be exploited in the years to come. “It’s very clear to many people that these also will be transformational as we move forward,” she says.

The materials research approach, which brings together researchers from across different science and engineering fields to solve complex problems, provides a model for solving 21st Century challenges in energy, environment and sustainability; health care and medicine; vulnerability to human and natural threats; and expanding and enhancing human capability and joy. “These are exemplars, but you can see materials written all over this list, and I would posit that any comparable list you might come up with would have materials written all over it,” Phillips said. “In order to address those grand challenges, we really need to be able to treat realistically complex systems that bring together all of these disciplines from the sciences, from engineering, from the social and behavioral sciences, and arguably even from the arts.”

Progress in scientific understanding and computational modeling are accelerating researchers’ ability to predict the structure and properties of new materials before actually making them, Phillips said.

MIT faculty members Antoine Allanore, Polina Anikeeva, A. John Hart, Pablo Jarillo-Herrero, Juejun Hu, and Jennifer Rupp presented research updates on their recent work which spans a range from ultra-thin layered materials for new electronic devices and cellular level probes for the brain and spinal cord to larger scale methods for 3D printing and metals processing.

Merging 2D materials with CMOS

Associate Professor of Physics Pablo Jarillo-Herrero stacks atomically thin, two-dimensional [2D] layers of different materials to discover new properties. Jarillo-Herrero’s lab demonstrated photodetectors, solar cells and the world’s thinnest LED. With materials such as tungsten selenide [WSe2], changing the number of layers also changes their electronic properties. Although graphene itself has no bandgap, closely aligning the lattices of graphene and boron nitride opens a 30-millivolt bandgap in graphene, he said.

“You have full electronic control with gate voltages,” Jarillo-Herrero said. Using bilayer molybdenum ditelluride, which is 10,000 times thinner than a silicon solar cell, he showed in work published in Nature Nanotechnology, a photodetector just 10 nanometers thick can be integrated on a silicon photonic crystal waveguide.

“You can just stack this at the very end of your CMOS [complementary metal oxide semiconductor] processing, and you don’t have to do any extra fabrication, any extra growth, you can just slap it on top,” Jarillo-Herrero explained. “It can be made as thin as 4 nanometers, so it’s still ultra thin, and you have a high degree of control in an ultra thin platform. The whole thing is semitransparent so we can see the light go in and out.” These new devices can be operated at telecommunications wavelengths by tuning the bandgap of the material.

Phase change materials

Juejun (JJ) Hu, the Merton C. Flemings Associate Professor of Materials Science and Engineering, is reducing power consumption, shrinking device size and ramping up processing speed with innovative combinations of materials that alternate between two different solid states, or phases, such as an alloy of germanium, antimony, selenium and tellurium. These materials are the basis for nonvolatile storage, meaning their memory state is preserved even when the power is turned off. Hu collaborated with MIT Professor Jeffrey C. Grossman and former postdoc Huashan Li to identify desirable materials for these alloys from first principles calculations, and graduate materials science and engineering student Yifei Zhang did much of the experimental work.

An earlier generation of devices based on germanium, antimony and tellurium [GST] suffers from losses to light absorption by the material. To overcome this problem, Hu substituted some of the tellurium with a lighter element, selenium, creating a new four-element structure of germanium, antimony, selenium and tellurium [GSST]. “We increase the bandgap to suppress short wavelength absorption, and we actually minimize any carrier mobility to mitigate the free carrier absorption,” he explained. Switching between amorphous and crystalline states can be triggered with a laser pulse or an electrical signal.

Although the structural state switching happens on the order of 100 nanoseconds, figuring out the techniques to accomplish it took a year of work, Hu said. Specifically, he found that using materials that switch between amorphous and crystalline states allows light to be directed over two different paths and reduces power consumption. He coupled this GSST optical phase change material with silicon nitride microresonators and waveguides to show this behavior. These switches based on phase change materials can be connected in a matrix to enable variable light control on a chip. Ultimately, Hu hopes to use this technology to build re-programmable photonic integrated circuits.

New tools for brain exploration

Class of 1942 Associate Professor in Materials Science and Engineering Polina Anikeeva works at the border between synthetic devices and the nervous system. Traditional electronic devices, with hardness like a knife, can trigger a foreign-body response from brain tissue, which typically is as soft as pudding or yogurt. Working with Prof. Yoel Fink and other MIT colleagues, Anikeeva developed soft polymer-based devices to stimulate and record activity of brain and spinal cord tissue borrowing from optical fiber drawing techniques.

An early version of their multi-functional fibers included three key elements: conductive polyethylene carbon composite electrodes to record brain cell activity; a transparent polycarbonate waveguide with cyclic olefin copolymer cladding to deliver light; and microfluidic channels to deliver drugs.

“Using this structure, for the first time, we were able to record, stimulate and pharmacologically modulate neural activity,” Anikeeva said. But the device recorded activity from clusters of neurons, not individual neurons. Anikeeva and her team addressed this problem by integrating graphite into the polyethylene composite electrodes, which increased their conductivity enough to shrink them into a structure that is as thin as a human hair. The device has six electrodes, an optical waveguide and two microfluidic channels.

Yet adding graphite increased the size and hardness of the glassy polycarbonate device, so her group turned to a new process using rubbery, stretchy polymers that they then coated with a conductive metal nanowire mesh. “This mesh of conductive metal nanowires can maintain low impedance even at 100 percent strain, and it maintains its structural integrity without any changes up to 20 percent strain, which is sufficient for us to operate in the spinal cord,” Anikeeva said.

Her students implanted these nanowire-mesh coated fibers in mice, which allowed them to stimulate and record neural activity in the spinal cord. A video showed a mouse moving its hindlimb when an optical signal delivered to the lumbar spinal cord traveled down the sciatic nerve to the gastrocnemius muscle. In these experiments, the device implanted in mice showed no decline in performance a year after surgery, Anikeeva said.

More recently, Anikeeva developed iron oxide-based nanoparticles that heat up in an applied magnetic field, which can trigger a response from neurons in the brain that express ion channels that are sensitive to heat such as capsaicin receptor, the same mechanism that is triggered when we eat hot peppers. Experimenting with mice, Anikeeva injected these tiny particles deep in the brain in a section that is associated with reward. “In our lab, we have started by modeling hysteresis in magnetic nanoparticles, synthesizing a broad range of these nanomaterials by engineering iron oxide with dopants and looking at different sizes and shapes, developing power electronics and a biological tool kit to assess this process,” Anikeeva explained. “In this case, there is no external hardwire, no wires, no implants, nothing is sticking out of the brain… however, they can now perceive magnetic field.” she said. To quantify their results, the researchers measured calcium ion influx into neurons. Work is now focused on shortening the response time to a few thousandths of a second by improving the heat output of the magnetic nanoparticles.

Ceramics for Solid-State Batteries, CO2 Sensors and Memristive Computing

Jennifer L. M. Rupp, the Thomas Lord Assistant Professor of Materials Science and Engineering, presented research showing a solid lithium garnet electrolyte can lead to batteries miniaturized on an integrated circuit chip.

Safety concerns regarding lithium batteries stem from their liquid component, which serves as the electrolyte and presents a risk of catching fire in air. Replacing the liquid electrolyte with a solid one could make batteries safer, Rupp explained. Her research shows that a ceramic material made of garnet, a material that is perhaps more familiar as a gemstone, can effectively pass lithium through a battery cell, but because it is solid, can be very safe for batteries and also have the opportunity to be miniaturized to thin film architectures. This garnet is a four-element compound of lithium, lanthanum, zirconium and oxygen. “The lithium is completely encapsulated; there is no risk of inflammation,” Rupp said.

In published research, Rupp showed that pairing a lithium titanium oxide anode with a ceramic garnet electrolyte and blurring the interface between the two materials allowed much faster battery charging time for large-scale cells. Lessons learned from applying these garnet materials pointed also to a new use for carbon dioxide sensing. “We can reconfigure the electrodes to have one electrode which simply goes as a reference, and another which undergoes a chemical reaction with carbon dioxide, and we use a tracker potential to track the effective change of carbon dioxide concentration in the environment based on bulk processing,” she explained. Rupp is also developing strained multi-layer materials to improve storage for memristive memory and computing elements.

Frontier for metals at high temperature

Associate Professor of Metallurgy Antoine Allanore pointed out that from 1980 to 2010, the world almost doubled its consumption of materials, with the fastest growth in metals and minerals. Such demand is due to the formidable low cost and high productivity of materials processing. The majority of such processes involve at some stage a high temperature operation and often the molten state of matter. Developing the science and engineering of the molten state brings huge opportunities, for example heat management in high-temperature processes such as metals extraction and glass making.

Steelmaking, for example, is already a highly efficient manufacturing process, turning out rebar, coil or wires of steel at a cost less than 32 cents per kilogram [about 15 cents per pound]. “Productivity is actually the key criteria to make materials processing successful and matter at the scale of the challenge of adding 2 billion people in the next 20 years,” he said.

Allanore’s group demonstrated that tin sulfide at high temperature, about 1,130 degrees Celsius [2,066 Fahrenheit], is an effective thermoelectric generator. “We have indications that the theoretical figure of merit for some sulfides, can be up to 1 at 1,130 [degrees Celsius]. For molten copper sulfide for example, we have estimates of the thermal conductivity, the melting point, and we have a cost that is a little bit high in my opinion, but that’s the nature of the research,” Allanore said. When his group looked at existing data, they found that for many molten compounds of sulfur and a metal, such as tin, lead or nickel, the thermoelectric figure of merit, as well as the compositional phases, had never been quantified, opening a frontier for new materials science research at high temperature. “It’s actually very difficult to know what are the true properties of the liquid,” Allanore said. “I need to know if that material will have semiconductivity. I need to know if it’s going to be denser or lighter than another liquid. … We don’t actually have computational methods to predict such property for liquids at high temperature.”

To address the problem, Allanore studied the relation in high-temperature melts between transport properties, including electrical conductivity and Seebeck coefficients, and a thermodynamic property called entropy. “We’ve put together a theoretical model that connects the transport property, like thermal power, and the thermodynamic property like entropy. This is important because it works for semiconductors, it works for metallic materials and more importantly it allows to find out regions of immiscibility in liquids,” Allanore said. Immiscibility means a material in the given condition will separate into two phases that do not mix together and remain separate.

Allanore has also developed a new method for observing molten compounds such as alumina, using a floating zone furnace, which is a transparent quartz tube located at the focal distance of four lamps. “If we can do that with oxides, we would really like to do that with sulfides,” he explained, showing a picture of molten tin sulfide sitting on a graphite plate in the floating zone furnace. The wide range of temperatures and properties of molten materials, “the ultimate state of condensed matter”, allows for better heat management, higher processing temperatures and electricity harvesting or electrical control of heat flow, he said.

3D printing a new manufacturing model

Traditional manufacturing requires economies of scale, in particular, large production volumes because of the fixed costs necessary to set up the production process, but 3D printing and other additive manufacturing technologies offer an alternative of high-performance, customizable products and devices, Associate Professor of Mechanical Engineering A. John Hart said.

Additive manufacturing is already a $6 billion a year business with reach from Hollywood special effects to high-tech jet engine nozzles. “Additive manufacturing already enables a diverse collection of materials, applications, and related processes – including by extrusion of plastics, melting metals, using lasers, and by coordinated chemical reactions that essentially are done with point wise control,” Hart explained.

“We can think of accessing new spaces in terms of the value of the products we create using additive manufacturing, also generally known as 3D printing. 3D printing is reshaping the axes by which we judge the economic viability of a manufacturing process, and allowing us to access new value spaces. For instance, we can think not only about production volume, but think about advantages in complexity of geometries, and advantages by customization of products to specific markets or even individuals. In these ways, 3D printing is influencing the entire product life cycle,” Hart said.

For instance, Hart’s group studied existing 3D printers to discover how to speed up the process from about 60 minutes to just 5 to 10 minutes to print a handheld mechanical part such as a gear. Former graduate student Jamison Go [SM, 2015] led this work, Hart said, building a desktop 3D printer about the size of a small microwave oven. The system features a control system for the printhead that moves the motors to the corner; an extrusion mechanism that drives the feedstock polymer filament like a screw; and a laser that penetrates and melts the polymer.

“By combining the fast motion control, the high heat transfer, and the high force, we can overcome the limits of the existing system,” Hart explained. The new design is three to 10 times faster in build rate than existing machines. “These kinds of steps forward can also change how we think about producing objects. If you can make something fast, you can think about how you might, or how others might, work differently,” he said. He mentioned, for instance, physicians who may need to 3D print a part for an emergency medical operation, or a repair technician who could use a 3D printer rather than hold inventory of many spare parts.

Hart’s group is currently working in collaboration with Oak Ridge National Lab on algorithms for optimization of 3D printing toolpaths, and adapting his innovations to large-scale 3d printers. “We can think about upscaling these principles to high productivity systems that are not only printing small things but printing big things,” Hart said. Hart has also worked with 3D printing of cellulose, which can be used for customization of consumer products and antimicrobial devices, and is the world’s most abundant natural polymer. He co-founded the company Desktop Metal with three other MIT faculty members and Ric Fulop SL ’06, who serves as Desktop Metal’s CEO. “The company is only two years old and will soon ship its first product which enables an entirely new approach to metal 3D printing,” Hart said.

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Denis Paiste, MIT Materials Research Laboratory
October 30, 2017

Coming up in November Newsletter: Materials Day Panel Discussion and Poster Session coverage

 

 

 

MRL Logo
Materials Day 2017
Interdisciplinary materials science model offers key to progress
Bringing together researchers from different science and engineering fields promises solutions to global needs in energy, health and quality of life.

 
Read More
Material could bring optical communication onto silicon chips Selective memory – New data caches 33 to 50% more efficient

Noelle Selin: Tracing toxins around the world
Chronicle features Felice Frankel’s scientific imagery
 
Chemistry World highlights Allanore potash research
  

Upcoming Events 

  • Seminar: Functional Hybrid Nanomaterials, From Fundamentals to Applications, Cornell University Professor Uli Wiesner, 6-104, MIT Chipman Room, 4pm,  Thurs., Nov. 2, 2017.
     
  • Pappalardo Distinguished Lecture: “Our Galactic Center, A Unique Laboratory for the Physics & Astrophysics of Black Holes,” UCLA Professor Andrea Ghez, 4pm, MIT Room 10-250. Refreshments at 3:30pm in 4-349, Pappalardo Community Room.
     
  • MIT Industrial Liaison Program Research and Development Conference, Wed., Nov. 15: 7:30am-5pm, Thurs., Nov. 16: 7:30am-1:30pm. Explore sensing, Internet policy research, the future of transportation, advanced manufacturing, novel materials, and more.Sessions will be held at Kresge Auditorium (W16), MIT Walker Memorial (Building 50), and Stratton Student Center (W20). Register
     
  • 2017 MRS Fall Meeting, Hynes Convention Center, 900 Boylston St., Boston, Sheraton Boston Hotel, 39 Dalton St., Boston, Mass. Nov. 26-Dec. 1, 2017. 
     
  • Special Chez Pierre Seminar: "Quantum devices in 2D material,”  ETH-Zurich Prof. Klaus Ensslin, MIT 4-331, 12pm, Tues., Nov. 28, 2017.

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Monday, 23 October 2017 15:06

Building 31 powers back up

Members of AeroAstro and MechE are returning to a dramatically renovated building, with robots, drones, and even a Corvette in tow.

MIT Building31 1 Daily LPaquette
Associate professors Julie Shah, Sertac Karaman, and Amos Winter, in front of the newly renovated Building 31. Photo, Lillie Paquette/MIT School of Engineering

A $52 million renovation of the 90-year-old Building 31 on MIT’s campus has transformed the space into a gleaming home for research in autonomy, turbomachinery, energy storage, and transportation. The three-year project added nearly 7,000 square feet of new space and doubled Building 31's capacity for faculty, students, and researchers.

Faculty and students are moving back in with their robots, drones, and even a Corvette in tow. “The architects even redesigned an entrance to be wide enough to drive a full-scale car in,” says Amos Winter, an associate professor in the Department of Mechanical Engineering (MechE), who works on automotive technologies.

At the heart of the building is the new Kresa Center for Autonomous Systems, a 80-foot-long by 40-foot-wide space boasting 25-foot ceilings dedicated for work in all types of autonomous vehicles including rotor and fixed-wing aircraft. The space was enabled by a gift from MIT alumnus Kent Kresa. Professor Jonathan How from the Department of Aeronautics and Astronautics (AeroAstro) describes the space as “one of the largest custom-designed, dedicated spaces for robotics research that I am aware of in academia.”

Read more at the MIT News Office.

Mark Veligor | School of Engineering
September 24, 2017