Colloidal Machines: How to Power, Program, and Apply Them?

Abstract:  The sustained operation of colloidal machines – that is, dynamic assemblies of colloidal components that perform useful functions – requires a steady input of energy, which must be delivered remotely and converted efficiently into useful motions. In this context, we have developed an electric motor that operates efficiently at small scales using electrostatic forces powered by steady electric (or electrochemical) currents. The underlying mechanism – termed contact charge electrophoresis (CCEP) – relies on the electrostatic actuation of conductive particles or droplets, which are repeatedly charged by contact with biased electrodes. In contrast to traditional forms of electrophoresis or dielectrophoresis, CCEP allows for rapid and sustained particle motions driven by low power DC voltages, which make it an ideal mechanism for powering the active components of small machines (e.g., mobile microfluidic technologies).  This talk will describe the basic physics underlying CCEP motions and present several strategies for rectifying these motions to achieve useful functions such as microfluidic droplet generation, particle transport, and fluid mixing.

Bio: Kyle Bishop received his PhD in Chemical Engineering from Northwestern University under the guidance of Bartosz Grzybowski for his work on nanoscale forces in self-assembly.  Following his PhD, Dr. Bishop was a post-doctoral fellow with George Whitesides at Harvard University, where he developed new strategies for manipulating flames with electric fields.  He started his independent career at Penn State University in the Department of Chemical Engineering. In 2016, Dr. Bishop moved to Columbia University, where he is currently an Associate Professor of Chemical Engineering. Dr. Bishop has been recognized by the 3M Non-tenured Faculty award and the NSF CAREER award.  His research seeks to discover, understand, and apply new strategies for organizing and directing colloidal matter through self-assembly and self-organization far-from-equilibrium.

All seminars are held on Wednesdays from 12:00 noon-1:00 p.m. in the Bowen Hall Auditorium Room 222. A light lunch is provided at 11:30 a.m. in the Bowen Hall Atrium immediately prior to the seminar.