AMHERST, Mass. – A team of researchers at the University of Massachusetts Amherst has received a four-year, $1.75 million grant from the National Science Foundation (NSF) to study and construct soft stretchable electronic devices that can be used in future healthcare, security and communications applications. The scientists plan to use conductive protein nanowires and mechanically soft nanomaterials to create a new nanocomposite that is strong, flexible and highly conductive.
The interdisciplinary research team is led by Stephen S. Nonnennman, associate professor of mechanical and industrial engineering, and includes Todd S. Emrick, professor of polymer science and engineering, Derek R. Lovley, Distinguished Professor of microbiology, and Jessica D. Schiffman, associate professor of chemical engineering. All four faculty members are affiliated with the Institute of Applied Life Sciences (IALS), which combines deep and interdisciplinary expertise from 29 departments on the UMass Amherst campus to translate fundamental research into innovations that benefit humankind.
Soft nanoelectronic composites are critical to advancing fields such as wearable devices, soft robotics, and personalized healthcare. “The conductive protein nanowires exhibit highly tunable conductivity while remaining significantly softer than carbon nanotubes or noble metals such as gold,” says Nonnenmann. “The second key point is that they disperse evenly in water, while nanotubes and metals clump together. These two factors really make pili-polymer nanocomposite pairings particularly exciting to explore and manufacture.”
The NSF Designing Materials to Revolutionize and Engineer our Future (DMREF) program is related to the national Materials Genome Initiative (MGI) which aims to “deploy advanced materials at least twice as fast as possible today, at a fraction of the cost.” MGI integrates experimental materials discovery with computational design. The DMREF team also includes Arthi Jayaraman, professor of chemical engineering and materials science at the University of Delaware, a world-renowned authority on computational studies of molecular-level phenomena. Together, their work “has the potential to bring the U.S. to the forefront of flexible electronics development, while training the next generation workforce to maintain this competitive advantage.”
Building the new soft electronics will require a new class of materials that exhibits high conductivity while also remaining chemically and mechanically compatible with the host matrix. Current stretchable electronics use thin, hard and brittle conductive materials such as metal nanowires or carbon nanotubes embedded in stretchable elastic polymers, but they often fail because of the mechanical mismatch between the materials. The new devices will use conductive protein nanowires, or pili, that will function as the conductive element of the protein-based soft electronics.
The team will leverage their collective expertise to design and develop protein nanowire-matrix pairings that are both highly functional and easily manufactured. Development of such structures will pair molecular modeling (Jayaraman) with synthetic biology (Lovley) to determine amino acid sequences that not only provide conductivity, but also anchor points to integrate into the polymer matrices (Emrick) and flexible fabrics (Schiffman) developed in parallel. Nonnenmann will evaluate their electronic-mechanical functionality using advanced microscopy and transport methods, thus forming a computational-synthetic-experimental feedback loop across the team. The goal of advantageously combining new synthetic polymers with these biologically derived protein nanowires is both intellectually challenging and vital to making advances in this bioelectronics field.