IBB Seminar

Sumita Pennathur
Professor of Mechanical Engineering
University of California, Santa Barbara

ABSTRACT
Over the last several decades, advances in micro- and nanofabrication have allowed researchers to miniaturize tools for a wide range of bioanalytical and biomedical applications. Beyond improving sensitivity, accuracy, and precision, reducing the dimensions of fluidic systems has enabled the exploitation of physical phenomena that emerge at small length scales. For example, when micro- and nanofluidic channels approach the characteristic length scale of the electrical double layers that form near charged surfaces, electrostatic interactions can strongly influence ion distributions, fluid motion, and molecular transport. By combining experimentally validated models with electrokinetic and optical measurements, we are developing a framework for understanding how changes in interfacial charge translate into changes in fluid and ionic transport. The resulting coupling between electrostatics, ion transport, and fluid dynamics creates opportunities for controlling fluids and molecules in ways that are not possible in conventional systems.  In this talk, I will present two examples from my research where fundamental understanding of these coupled phenomena has led to new capabilities. First, using bipolar electrodes, charged hydrogels, and conductive polymers such as PEDOT:PSS, we are investigating how the electrostatic state of an interface can be actively tuned to control local ion distributions, electric potential, and electrokinetic transport. Second, I will show how the same electrostatic principles operate at larger scales to drive mechanical motion in MEMS, where our zipper actuators and pumps use electrically driven deformation to meter extremely small fluid volumes in compact, low-power devices. Together, these efforts aim to establish electrostatics as an active engineering tool for controlling ions and fluids, with applications ranging from tunable micro- and nanofluidic systems to wearable drug delivery and next-generation biomedical devices.

BIO 
Sumita Pennathur is a Professor of Mechanical Engineering at the University of California, Santa Barbara. With degrees from MIT (B.S., M.S.) and Stanford (Ph.D.), she is a leading expert in nanofluidics, electrokinetics, and bioanalytical systems. Her groundbreaking research merges fundamental fluid physics at the micro- and nano-scale with practical device design, resulting in publications, patents, and several successful startups, including Asta Fluidics, Alveo Technologies, and Laxmi Therapeutic Devices. Among numerous honors, she received the prestigious PECASE award and the ADA Visionary Award.

Mark Prausnitz, faculty host