(153d) In Situ Measurements of Particle Electrophoresis in Dynamic Environments

Suspended particles are a fundamental component of numerous scientific fields and engineering applications and precise knowledge of particle zeta potential crucial to predicting particle behavior in different environments. We present a novel microfluidic technique for in situ measurement and visualization of particle zeta potential under chemically dynamic environments.  We have incorporated hydrogel microwindow membranes into microfluidic devices which allow for rapid dialysis of solutions in and out of microchannels while remaining fully permeable to electric fields. We are thus able to measure particle electrophoretic mobility under AC fields while simultaneously changing the chemical environment surrounding it, allowing for investigation of spatially and temporally varying effects on particle surface charge.