This NSF/DMR-BSF award by the Biomaterials program in the Division of Materials Research to Duke University aims to produce, model and study innovative materials that are inspired by biological structures. This is a collaborative proposal with scientists from US and Israel (Ben Gurion University of the Negev), and this award is co-funded by the Global Venture Funds program in the Office of International Science and Engineering. The scientific goal of this project is to put the ingenuity of nature to the service of modern electronics and devices for environment friendly applications in transportation, energy production and storage, sensing, and other environmental challenges. Applications of these technologies would be very important in the automotive industry, in industrial energy production processes, and in providing energy sources for implantable biomedical devices. While biological materials proteins may not function well in these targeted applications of interest, borrowing some of the motifs and building blocks of nature can be used to produce materials that capture some of the critical functions of biomolecules, while still functioning effectively in demanding non-biological settings. The proposed theoretical and experimental studies are expected to advance the development of components based on biological building blocks. In addition, the proposed theoretical studies would enable the accurate modeling of molecular mechanisms at an atomic level. The collaborative experimental-theoretical nature of this project promotes great cross-training of students in a lively multi-disciplinary setting that will include students and faculty members from two universities at USA and Israel. In mentoring the students, the proposal is particularly attentive to novel curriculum developments, and in recruiting and mentoring underrepresented groups into careers in science and technology.
This project combines theoretical and experimental studies with chemical synthesis and materials characterization to design and elucidate the function of bioinspired electron-proton transport membranes. Extensive studies indicate that the alignment of proton-conduction channels is required for high proton conductivities in these bioinspired structures. This finding motivates the study of self-assembling pi-stacked polypeptides that form beta sheets and lead to designed pathways for proton transport. The main objective of this project is to explore the mechanisms of charge transport (proton and/or electron transport, or coupled proton-electron transport) in biological protein assemblies with beta-sheet architecture (fibrils and nanotubes) using a variety of theoretical and experimental approaches. Fundamental understanding of proton and electron and coupled proton-electron transport mechanisms in these specific examples of biological assemblies will help to establish the structure-function relationship to optimize conductive properties of bioinspired materials. These structures of interest involve natural and engineered amino acids (with modified side-chains) that can self-assemble into fibers or nanotubes because of key hydrogen-bonding motifs. Since proton transfer can involve between side chains and amide bonds, these assemblies promise to provide intrinsic networks with effective long-range proton transport relays. Preliminary data in the investigator's laboratory support the concept of developing lower-cost materials that may, in the long run, be able to compete with favorable proton-transport membrane materials (e.g., Nafion), and yet to operate in a widened ranges of temperature and hydration states. In addition, the biomaterials under study may support tunable channels for proton-coupled electron transport, which would provide advantages for the development of hydrogen separation structures. The theoretical study of charge transport in these materials will extend earlier theories to the mesoscale, encompassing transport on the scale of thousands of molecules. The theoretical studies in the project will use simulation tools that range from ab initio methods to coarse-grained molecular dynamics and mathematical modeling. By combining synthesis, theory, and materials characterization, the project will attempt to realize the promise of this field. The scientific broader impact of this project is to put the ingenuity of nature to the service of modern electronics, which may produce desirable long-term impacts on transportation, energy production and storage, sensing, and environmental challenges.
