In celebration of Women's History Month in the US (March), the #seeHER movement features materials researcher Paula T. Hammond of the Massachusetts Institute of Technology for her work on nanomaterials in drug-delivery systems. For more details on this work, see the MRS-TV interview with Prof. Hammond about her Fred Kavli Distinguished Lecture given at the Plenary session during the 2018 MRS Fall Meeting.
The 2018 MRS Fall Meeting & Exhibit came to a successful conclusion on Friday, November 30, with over 6,500 attendees and 234 exhibitors. Our congratulations go to Meeting Chairs Kristen H. Brosnan, David A. LaVan, Patrycja Paruch, Joan M. Redwing, and Takao Someya for putting together an excellent technical program along with various special events. MRS would also like to thank all the Symposium Organizers, Session Chairs, and Symposium Assistants for their part in the success of this meeting. A thank you goes to the Exhibitors, Symposium Support, and to the sponsors of the special events and activities.
Contributors to news on the 2018 MRS Fall Meeting & Exhibit include Meeting Scene reporters Daniel Gregory, Sean Langan, Hortense Le Ferrand (@HortenseLeFerra), Tianyu Liu (@Tianyuliu_Chem), Judy Meiksin (@Judy_Meiksin), Don Monroe, Arthur L. Robinson, Arundhati Sengupta, and Ashley White; Bloggers JuFang Hu (@Jufang6), Biplab Sarkar (@biplab_chem), Armin VahidMohammadi (@armin_vm), and Jingyi Yang (@JingyiYang14); and photographers Stephanie Gabborin and Heather Shick; with newsletter production by Jacqueline DuMont and Shayla Poling, and newsletter design by Erin Hasinger.
Thank you to MRS Meeting Scene sponsors SPI Supplies, Harrick Plasma, National Electrostatics Corp., Goodfellow Corporation, Lake Shore Cryotronics, Inc., American Elements, Wiley, Rigaku, JEOL USA, Inc., Bruker, and Thermo Fisher Scientific.
Thank you for subscribing to the MRS Meeting Scene newsletters from the 2018 MRS Fall Meeting & Exhibit. We hope you enjoyed reading them and continue your subscription as we launch into the 2019 MRS Spring Meeting & Exhibit - the conversation already started at #s19mrs! We welcome your comments and feedback.
Svetlana Boriskina, Massachusetts Institute of Technology
Wearable Fabrics for Passive Heating and Cooling - Can Polyethylene Do Both?
Written by Daniel Gregory
Fabrics provide a key additional layer that helps to regulate human body heat. In extreme environments, current clothing options are typically either very bulky, cool passively using moisture wicking from sweat, or have poorly integrated elaborate active cooling systems. Svetlana Boriskina explored the ability of polyethylene to provide both active and passive cooling effects. Polyethylene was chosen due to its low absorption of near-infrared wavelengths, emitted for radiative cooling in humans. Other textile fabrics usually absorb strongly in this region, and so are unable to let heat escape to cool properly, or reflect the heat back to the wearer, though metals can be added for this reflection.
The challenge with polyethylene is to make it visible in the near infrared yet opaque at visible wavelengths. To do this, Boriskina explained how she and her group were able to create fibers with diameters roughly equal to the wavelength of visible light but thinner than infrared radiation, causing a scattering effect that provided the visible light opacity. This was further demonstrated through infrared and visible camera comparisons. Polyethylene processed in several different ways was then compared to metallized emergency blankets and unprotected bare skin analogue in their ability to insulate heat given off by a surface and also keep that surface cool under sunlight. It was shown that powerful heating or cooling effects depended on the processing method, with knitted polyethylene outperforming the emergency blanket in thermal insulation while nanoporous polyethylene was the most effective cooling fabric, and showed promise as a material for thermal camouflage. Boriskina presented tests of moisture wicking and drying time, showing surprisingly that knitted polyethyelene performed best despite the polymer usually being hydrophobic. The material was also shown to have many other properties such as its light weight and the ability to be processed into fabric on conventional equipment and in a range of colors, as well as already having a well-established recycling procedure.
What are SAMS?
Self-assembled monolayers (SAMs) are capable of changing the surface properties of a material and therefore relevant for many fields in science. The video shows a simple way to prepare them and also defines them and describes some of their applications.
The 2018 SciVid Competition is sponsored by the Materials Research Society Foundation, Goodfellow, and A. J. Drexel Nanomaterials Institute.
Michael Strano, Massachusetts Institute of Technology
From Energy Harvesting to Living Plants—Concepts in Biosensing and Energy Conversion Using Carbon Nanomaterials
Written by Daniel Gregory
As he presented an expansive variety of ideas currently under research, Michael Strano provided an excellent example of how modular and customizable nanomaterials can be. He began his talk with work on transitioning the extraordinary mechanical properties of carbon nanotubes and graphene into macroscopic materials. This was achieved by growing graphene from chemical vapor deposition on a substrate, then rolling or folding the substrate into a fiber or sheet, respectively. By doing this, Strano and his group were able to extend reinforcement throughout the dimensions of their material, greatly improving the reinforcement of the composite while reducing the volume fraction. Following this was a brief explanation of a thermal resonator, using the thermal effusivity of carbon nanomaterials to make a device capable of generating power from temperature fluctuations in ambient conditions. The talk moved swiftly on to the properties of nanoconfined water, using temporal Raman spectroscopy to observe fluids moving through nanotubes. The group was able to confirm previously described theoretical predictions and experimentally expand the understanding of highly distorted fluids. Pivoting, Strano gave a detailed description of his group’s ability to embed readable and writable circuits in colloidal nanoparticles using two different methods. After talking briefly about near-infrared fluorescent single-walled nanotubes and their applications in individual protein sensing, Strano concluded with a description of how nanotube-wrapped DNA molecules were shown to penetrate previously impenetrable membranes in plants, such as the chloroplast membrane. After developing models and equations to describe this motion, Strano finished with some intriguing applications in chemical sensing and bioluminescence.
Written by Sean Langan
Late Thursday afternoon, MRS members who had not yet headed home from the conference were treated to a wonderful lecture from Laura Na Liu, who was selected to give The Kavli Foundation Early Career Lecture in Materials Science due to her outstanding work in the field of plasmonics, specifically DNA-based dynamic plasmonic nanosystems. She calls her work DNA origami. For this origami, hundreds of short DNA strands are formed into complex two- and three-dimensional architectures. These form templates for functionalized DNA capture strands that extend from the origami, and because of the nature of DNA binding, these functionalized capture strands can be placed with incredible accuracy, and be used as the basis for complex nanosystems with optical functionality. With these nanosystems Liu is successfully mimicking the motor-like functions present in biological cells, such as rotary motors like FOF1-ATP synthase, and linear motors like Kinesin-1, Myosin, and Kinesin-5.
Liu’s first example of her work was a system with rotation. Two of the DNA origami bundles form a cross-like structure, with functionalized gold plasmonic particles on its top and bottom, forming a rotary system. These can form chiral left-handed and right-handed configurations. When specific DNA strands are added to the solution with the rotary system, they interact with the functionalized capture strands on the DNA origami to cause it to rotate between a relaxed state, a right-handed state, and a left-handed state. Through circular dichroism spectroscopy, these three states can be identified.
A problem with this technique is system degradation because of dilution that comes from adding more DNA strands, so Liu and her team began to experiment with using light as a switch for the rotary system instead. To do this, Azobenzene molecules, which change from a trans configuration to a cis configuration when exposed to UV light, and vice versa when exposed to visible light, were used. These molecules were placed between DNA bases so the functionalized DNA could change from a hybridized form to a dehybridized form, and vice versa, when light interacts with it. With this, light can change the rotational system from a locked to relaxed state. Other methods of control such as magnetic or pH control are being investigated as well. This kind of rotational system can be functionalized to detect several compounds in real time—cocaine and ATP were given as examples—when used in conjunction with circular dichroism spectroscopy.
Liu went on to show that this technique could be used for more than just changing the angles of one of these structures, but for full rotation as well. To do so, a DNA origami ring has 8 pairs of complementary strands placed across from each other, and by adding the correct paired strands to the solution, a separate piece of DNA origami can rotate around this structure.
A similar technique can be used to make a gold nanorod “walk” across a DNA origami platform. The gold nanorod is functionalized, as is the origami platform at regular intervals. Strands of DNA are added to the solution, one causing a functionalized strand from the platform to release the nanorod, while another causes a strand on the platform to bind with the nanorod farther down, creating a walking effect across the origami platform.
Using the Kinesin-5 protein that moves microtubules in a cell as a model, Liu developed a system plasmonic sliding system as well. Two gold nanocrystals are placed between two DNA origami pieces, and act as rollers between them. Using the same technique as before, these two nanocrystals will slide the origami pieces in opposite directions.
To conclude, Liu reiterated that through manipulating DNA and plasmonics, artificial devices can be created. As a next step, Liu wants to bring the various systems she has developed, both rotary and linear motors, together to make a single device.
The Kavli Foundation is dedicated to advancing science for the benefit of humanity, promoting public understanding of scientific research and supporting scientists and their work.
Brian Litt, Penn Epilepsy Center
Engineering the Next Generation of Neurodevices—New Materials and Clinical Translation
Written by Hortense Le Ferrand
Innovation in materials science can help clinicians in many ways. As an example, Brian Litt from the Penn Epilepsy Center introduced the case of an epileptic patient suffering from regular seizures. By implanting four electrodes into the brain of the patient, the clinicians could determine where abnormal activity occurs and locally ablate those areas. This is the technology used to treat epilepsy for the past 20 years and still used today. As a result, the patient had less intense seizures, but still some epileptic symptoms remain.
Litt described several areas where materials researchers can work together with medical doctors to improve the therapy and treat the patient. First, decreasing the size of the electrodes and improving their biocompatibility would reduce the inflammatory response post-implantation and the tissue damage. Second, increasing the number of electrodes to a reasonable amount could allow a more accurate detection of the epileptic network location. Third, development of a cloud-based system to collect, compute, and interpret the data from the electrodes is also needed.
If there is a lot of progress and innovation in the fabrication of multiple channels electrodes and biocompatible materials, there is still a significant gap between the research and the concrete applications. Litt emphasizes with this example the need for collaborations to achieve translational applications.
MRS Graduate Student Awards are intended to honor and encourage graduate students whose academic achievements and current materials research display a high level of excellence and distinction. MRS recognizes the following students of exceptional ability who show promise for significant future achievement in materials research.
Gold Award
Hyeon Seok An, Ulsan National Institute of Science and Technology
Megan E. Beck, Northwestern University
Lucas M Caretta, Massachusetts Institute of Technology
Janna Domenico, Drexel University
Mihai Duduta, Harvard University
William Gent, Stanford University
Seokhyoung Kim, University of North Carolina at Chapel Hill
Zhe Li, Iowa State University
Yayuan Liu, Stanford University
Kelly W. Mauser, California Institute of Technology
Jing Yang, Massachusetts Institute of Technology
Wenjie Yang, The Australian National University
Silver Award
Ankita Bhutani, University of Illinois at Urbana-Champaign
Snehashis Choudhury, Cornell University
Mohammad Faqrul Alam Chowdhury, McGill University
Mohamed Elhebeary, University of Illinois Urbana Champaign
Victor Fung, University of California, Riverside
Yue Gao, The Pennsylvania State University
Jianhe Guo, The University of Texas at Austin
Jiuk Jang, Ulsan National Institute of Science and Technology
Hariom Jani, National University of Singapore
Ivan Lemesh, Massachusetts Institute of Technology
Lu Li, Rensselaer Polytechnic Institute
Meng Li, Tufts University
Qi Li, Carnegie Mellon University
Wenjie Li, University of Wisconsin-Madison
Yanbin Li, Stanford University
Yongtao Liu, Oak Ridge National Laboratory
Nathan Nakamura, Carnegie Mellon University
Xinchen Ni, Massachusetts Institute of Technology
Khalil Ramadi, Massachusetts Institute of Technology
Xinjian Shi, Stanford University
Ruitao Su, University of Minnesota
Atsunori Tanaka, University of California, San Diego
Danqing Wang, Northwestern University
Kehao Zhang, The Pennsylvania State University
Arthur Nowick Graduate Student Award
In addition, this year’s Arthur Nowick award goes to Hariom Jani of the National University of Singapore. This award honors the late Dr. Arthur Nowick and his lifelong commitment to teaching and mentoring students in materials science. MRS acknowledges the generous contribution for the Nowick Award to the MRS Foundation from Joan Nowick in memory of her husband Dr. Arthur Nowick.
Philipp Simmons, Massachusetts Institute of Technology
All-Solid-State Glucose Fuel Cell for Energy Harvesting in the Human Body
Written by Daniel Gregory
Wearable devices and implants within the human body require a reliable source of power. Fuel cells operating through the oxidation of glucose to gluconic acid are an attractive option; however, current devices predominantly use polymer membranes or liquid electrolytes to separate the membranes. This leads to immense challenges with rapid degradation, unpredictability, and an inability to miniaturize the system, leading to insufficient power density. Philipp Simmons introduced an all solid-state glucose fuel cell using a solid ceria membrane and a porous platinum catalyst. The materials are all biocompatible and provide a high power density, and the device is fabricated on silicon for easy integration to other devices.
A key challenge when fabricating these devices was the mechanical stress imposed by the pulsed laser deposition (PLD) of the ceria. By lowering the background pressure in the PLD system, Simmons found that the microstructure of the ceria changed, with grain sizes increasing as the film grew away from the silicon substrate, reducing strain. The novel microstructure also improved device performance due to the ceria now becoming nanoporous. Simmons then explained the mechanism of proton transport in ceria and the way in which the device was able to confirm this, before concluding with a detailed presentation of the device performance. Of note was the high current density even in unengineered devices, and a record high cell potential nearly triple current literature values. More work is being done by the group to determine the causes for this and further optimize the device performance.