Abstract:

Micro and nanopatterning of rigid materials such as semiconductors, metals, and dielectrics has revolutionized human life by enabling integrated circuits, microsensors, and smart phones. Imagine applying the same micro/nano patterning principles and multi-scale integration to biological and living materials. We could then create adaptable implants, living robots, microphysiological systems, and homeostatic materials. This talk will describe our efforts to apply micro and nanoscale patterning and heterogeneous integration to hydrogels and living cells/organoids. I will describe shell microelectrode array interfaces for brain organoids for organoid intelligence (O.I). I will describe shape-changing temperature responsive and DNA polymerization gels that display diverse functions such as gripping, locomotion, and complex programmable shape change. I will give examples wherein such hydrogel transformers can be applied widely, including for adaptive implants, soft-robots, digitally programmable materials, and automata). I will also describe the first demonstration of the patterning of live cells with nanolithographic arrays of gold dots and wires using a biocompatible biotransfer process. Integrating lithographic patterns on live cells offers the potential to create living material interfaces and incorporate electronic/optical tattoos. These studies indicate the potential for the design of a range of intelligent materials, robots, and integrated devices that have the touch and feel of biological matter.

Biography:

David Gracias is a Professor at the Johns Hopkins University with a primary appointment in Chemical and Biomolecular Engineering in the Whiting School of Engineering and secondary appointments in the Krieger School of Arts and Sciences and the Johns Hopkins School of Medicine. Prof. Gracias received his PhD from UC Berkeley and did post-doctoral research at Harvard University prior to starting his independent laboratory. He has made pioneering contributions to micro and nanotechnology as described in over 200 technical publications, including several in high impact journals such as Science. He is also a prolific inventor and holds 36 issued US patents, with notable inventions on microchip integration, self-folding polyhedra, integrated biosensors, programmable soft-robots and untethered microgrippers. He has been recognized by several national and international awards (including the NSF Career, NIH Director’s New Innovator, Beckman Young Investigator, Camille Dreyfus Teacher Scholar and Bessel Award) and elected as a Fellow of diverse international scientific and engineering societies, including AAAS, IEEE, APS, RSC, and AIMBE.

**Refreshments will be served beginning at 3:30 pm in the Olin lobby