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Home | Seminars and Symposia | Past seminars/symposia: Monday, March 31, 2003

DTC Seminar Series

Hydrogel-Based Microsystems for Physiological Sensing and Active Flow Control


Babak Ziaie
University of Minnesota

Monday, March 31, 2003
3:30 pm

402 Walter Library

Slide presentation (pdf 2.9 MB) Environmentally sensitive hydrogels offer unique opportunities for active flow control in microflow systems. These tangled networks of cross-linked polymer chains, immersed in a solvent, manifest a reversible and abrupt swelling phase transition in response to changes in environmental factors such as glucose concentration, pH, electric field, temperature, and light. This transition often results in an abrupt volume change (swelling or shrinking) that can be as large as 1000 fold or more. Because of this property, hydrogels are attractive candidates as components of microactuators operating in aqueous media such as body fluids. For example, the volume phase transition in these materials can be harnessed in smart microfluidic components used for implantable drug delivery systems. In this seminar, Dr. Babak Ziaie will discuss several MEMS-based hydrogel-actuated microflow control devices developed in our laboratory at the University of Minnesota. These include: 1) a hydrogel-actuated microvalve with a porous back-plate, 2) a hydrogel-gated smart flow controller, and 3) a microvalve with double side tethered structure for the entrapment of hydrogel.


Dr. Babak Ziaie is currently an assistant professor of Electrical/Computer and Biomedical Engineering at the University of Minnesota. Dr. Ziaie received his doctoral degree in Electrical Engineering from the University of Michigan in 1994. His dissertation project emphasized the development of an implantable single channel microstimulator for functional neuromuscular stimulation applications. From 1995-1999 he was a postdoctoral-fellow and an assistant research scientist at the Center for Integrated Microsystems (CIMS) at the University of Michigan. In October 1999, he joined the Department of Electrical and Computer Engineering at the University of Minnesota. His research group at the University of Minnesota works on a variety of projects mostly related to biomedical applications of MEMS and microsystems. These include implantable wireless microsystems for diagnosis and management of glaucoma, hydrogel-based microsystems for active flow control and drug delivery, multichannel wideband wireless interfaces for central nervous system, and ultra-sensitive detectors for biological (molecular and cellular) applications. Dr. Ziaie is the recipient of the NSF Career award in Biomedical Engineering (2001) and the McKnight Endowment Fund for Neuroscience Technological Innovations Awards in Neuroscience (2002).