Soft electronics aims to bridge the gap between functional, high performance, electronic devices and our soft, compliant, and organic environment. The use of 3D printing and direct write techniques offers distinct advantages for the integration of functional electronic devices onto non-traditional substrates and for the realization of compliant devices. The development of flexible, printable, and mechanically robust energy storage devices, in particular, is a key for many of these applications and will facilitate innovation in the manufacturing of flexible electronics. We have explored multiple approaches, including a mechanically robust and flexible current collector based on a nonwoven carbon nanotube mat, we demonstrate highly stable, bendable and even creasable Li-ion batteries. Additive manufacturing and direct write printing approaches enable direct integration of a power source into a device during the fabrication process. We utilized a well-dispersed and directly castable mixture of active material, carbon nanofibers, and polymer to make printable electrode inks. We also demonstrated a dry phase inversion printing technique to generate porosity within a polymer matrix and a ceramic Al2O3 filler to control pore size distribution and tortuosity. This technology for both electrolyte and electrode inks is an enabling step toward direct integration of flexible power in confined areas or on non-planar device surfaces.
Dr. Michael F. Durstock is a Technical Director (acting) of Functional Materials Division, Materials & Manufacturing Directorate, Air Force Research Laboratory (AFRL), on an assignment from his position of a Chief of the Soft Matter Materials Branch, where he defines, advocates, and executes the strategic vision for research and development activities in flexible electronic materials and devices, biomaterials and processes, and soft matter materials in general. Dr. Durstock holds Materials Science and Engineering BS degree from University of Cinincinnatti (1994) and PhD degree from MIT (1999). Prior to joining AFRL, Dr. Durstock worked for the Dow Chemical Company and NKK Corporation in Kawasaki, Japan. Dr. Durstock is active in a variety of different technical communities and his research interests center on flexible and stretchable hybrid electronic materials and processes. He leads research activities focused on nanostructured materials for high performance devices, including batteries, capacitors, and solar cells, as well as 3D printing and direct write techniques for integrated device concepts. He has co-authored more than 140 papers, several book chapters, and 9 patents. He has presented hundreds of invited presentations and seminars to academic, industrial, and government professionals and he continues to drive research and development collaborations.