Controlled Microfluidic Interfaces for Microoptics and Microsensing

Professor Hongrui Jiang, Assistant Professor, Department of Electrical and Computer Engineering, Faculty Affiliate with the Department of Biomedical Engineering, and a faculty member of the Materials Science Program, University of Wisconsin (UW)-Madison
Surface tension profoundly affects fluid behavior at the microscale. Through careful engineering, controlled liquid-liquid or liquid-gas interfaces at the microscale can be formed and used in many interesting applications. In this talk, I will present our work on applying such interfaces to microoptics and microsensing. I will first introduce a few types of microlenses and microlens arrays, including “smart” and adaptive liquid microlenses actuated by stimuli-responsive hydrogels, liquid microlenses in situ formed within microfluidic channels via pneumatic control of droplets, and polydimethylsiloxane (PDMS) microlens arrays fabricated through liquid-phase photopolymerization and molding. I will then discuss about a few microsensing techniques including chemical and biological sensing using dissolvable micromembranes in microchannels, chemical and biological sensing at liquid crystals interfacing either air or aqueous solutions, and collection of gaseous samples and aerosols through air-liquid microfludic interfaces.

Hongrui Jiang received the B.S. degree in physics from Peking University, Beijing, China, and the M.S. and Ph.D. degrees in electrical engineering from Cornell University, Ithaca, NY, in 1999 and 2001, respectively. He was a Postdoctoral Researcher at the Berkeley Sensor and Actuator Center, University of California-Berkeley, Berkeley, from 2001 to 2002. He is currently an assistant professor with the Department of Electrical and Computer Engineering, a Faculty Affiliate with the Department of Biomedical Engineering and a faculty member of the Materials Science Program, University of Wisconsin (UW)-Madison, Madison. His research interests are in microfabrication technology; biological and chemical microsensors, microactuators, optical MEMS, smart materials and micro-/nanostructures; lab on a chip; and biomimetics and bioinspiration. He received the National Science Foundation CAREER Award and DARPA Young Faculty Award in 2008.