Title: The Countoscope: Counting Particles to Measure Dynamic Properties of Suspensions In and Out of Equilibrium

Speaker: Brennan Sprinkle, Colorado School of Mines

Abstract: Modern microscopy techniques can image complex, microscopic systems with an unprecedented resolution - but methods to analyze these images are much less robust. Available techniques to probe dynamics rely on reconstructing particle trajectories, which can be difficult or impossible in some cases, or some form of video analysis, which can be unreliable and expensive. Inspired by the early work of Smoluchowski we introduce the `Countoscope', a technique that near completely ameliorates these issues by simply counting particle number fluctuations in observation boxes. By varying properties like the size or aspect ratio of the boxes and taking different measures of correlation between these observation boxes, we can `zoom' in or out to measure individual or collective particle kinetics in both passive and active systems. Using colloidal suspensions as a test case, we employ a combination of experiments, simulations, and analytical theory to support our findings.

Zoom: https://northwestern.zoom.us/j/97359869177

-----

To subscribe to the Applied Mathematics Colloquia List send a message to LISTSERV@LISTSERV.IT.NORTHWESTERN.EDU with the command:

add esam-seminar Youremail Firstname Lastname