Date: Thursday, Oct 18th
Presenter: Prof. Marco Rolandi, Department of Materials Science and Engineering, University of Washington
The ability to precisely manipulate, localize, and assemble biological and bioinspired molecules into organized structures has contributed to great advances in bionanotechnology. These advances include bioelectronics, biophotonics, tissue engineering, and regenerative medicine. For these applications, chitin is particularly appealing. Chitin is a naturally abundant polysaccharide, which is mechanically stable, biodegradable, nontoxic, and physiologically inert. Here, I will present our efforts to create nanoscale structures and devices using self-assembled chitin nanofibers. First, I will discuss a novel nanofabrication approach based on a chitin nanofiber ink, which self-assembles into ultrafine (3nm) nanofibers upon drying. This ink is coupled with airbrushing, replica molding, and microcontact printing to manufacture chitin nanofiber structures across length scales. Second, I will describe applications of these structures in biocompatible photonic devices and scaffolds for tissue engineering. Preliminary results in engineering neural networks and aligned cardiac tissue will be presented. Third, I will introduce the first biopolymer field effect transistor with protons (H+) as charge carriers. In a chitin derivative (maleic chitosan) nanofibers, H+ hop along the hydrated nanofiber hydrogen bond network following the Grotthuss mechanism. The H+ flow is measured with PdHx proton transparent contacts, and this flow is turned on or off by an electrostatic potential applied to a gate electrode. In nature, protonic (H+) and ionic (not electronic) currents are used to communicate information across cell membranes. As such, these biocompatible protonic devices may represent a versatile biotic-abiotic interface for bionanoelectronics.
Marco Rolandi, Ph. D., is an Assistant Professor of Materials Science and Engineering at the University of Washington (2008). He received his Ph. D. in Applied Physics from Stanford University (2005) working with Prof. Hongjie Dai and his postdoctoral training at the University of California, Berkeley (2008) working with Prof. Jean M. J. Fréchet. His research focuses on micro- and nano biological and bionspired structures and their integration in biocompatible devices. His work on bionanoprotonic transistors has been highlighted in the New York Times, EnGadget, Popular Science, MRS 360, IEEE Spectrum, Materials Views, and other sites. He was nominated TR-35 GI (one of the top Italian innovators under 35) by the MIT Technology Review (Italy). He was the recipient of an NSF-CAREER award in 2012 and a 3M Nontenured Faculty award in 2010.