CPM Seminar

The Benefits of Being Thin: The Revolutionary Potential of Ultrathin Membranes for Biology and Medicine

Jim McGrath

University of Rochester

Nearly a decade after we first used silicon microfabrication to create free-standing ultrathin nanoporous membranes, the materials are beginning to realize their potential to create paradigm shifts in multiple disciplines. Today, as a team of more than two dozen faculty, students, entrepreneurs, and engineers at multiple academic institutions and one company, we manufacture and apply a variety of nanoporous and microporous membranes with the common characteristics that they are ultrathin (15 nm - 300 nm) and made from silicon-containing materials. Because these ‘nanomembranes’ are orders-of-magnitude thinner than conventional membranes, they are orders-of-magnitude more permeable to both diffusing molecules and pressurized flow. Molecular scale thickness also enhances the resolution of separations when the membranes are used as sieves. High permeability and high resolution sieving, as well as other expected and unexpected characteristics of nanomembranes, have sparked research programs on topics as disparate as electroosmotic pumps and hemodialysis. This talk will first review our progress in establishing the basic science of ultrathin porous membranes. Through modeling and experimentation we have developed a fundamental understanding of convective and diffusive flows, sieving behavior, fouling, mechanics, and electrokinetic properties. We will then review progress on each of four major applications areas that have emerged as nanomembranes have become reliably manufactured and affordable in recent years: 1) biological separations, 2) electromechanical devices, 3) barrier tissue models and 4) biosensors.