Microsystems Seminar: David Gracias, "From metamaterials to dust-sized surgical tools"
Tuesday, October 20, 2015
1146 A.V. Williams Building
Origami microsystems: From metamaterials to dust sized surgical tools
Professor and Russell Croft Faculty Scholar
Department of Chemical and Biomolecular Engineering
Department of Materials Science and Engineering
Institute for Nanobiotechnology
Johns Hopkins University
Strain engineering can be combined with lithography to transform planar thin films patterns into three dimensional structures. In this talk, I will discuss strategies to pattern metals, 2D layered materials such as graphene, polymer and hydrogel films so that they assemble either spontaneously or in response to a stimulus into static or reconfigurable materials and devices via capillary forces, thin film stress and swelling. It is important to note that in our work, we do not utilize any kind of electrical wiring or active control over the folding or bending pathways; rather the structures self-assemble into their energetic minima when the forces within the material balance each other.
There are several advantages of this approach including, (a) parallel scalable assembly both on-chip and off-chip, (b) precise patterning of nanometer sized features in all three dimensions, (c) facile layering of films in a rolled or folded architecture and (d) actuation without the need for external or on-board power sources. I will highlight applications of these approaches in the construction of metamaterials, bio-origami hydrogels, lab-on-a-chip devices, stimuli responsive drug delivery systems and tiny surgical tools. I will also discuss our studies on the first ever in-vivo biopsies using dust sized forceps.
Prof. Gracias studied at the Indian Institute of Technology (undergraduate), UC Berkeley (PhD, 1999) and Harvard University (post-doc) and worked in R&D at Intel Corporation prior to starting his independent laboratory at the Johns Hopkins University in 2003. He has published over 100 journal publications in prestigious journals such as Science, PNAS, Nature Communications and Nano Letters and has 26 issued US patents. Significant awards include the NIH Director’s New Innovator Award, the DuPont Young Professor Award, Beckman Young Investigator Award, Camille-Dreyfus Teacher Scholar Award, Maryland Outstanding Young Engineer Award and the NSF Career Award. He is a Fellow of the American Institute for Medical and Biological Engineering (AIMBE).