Dynamic optical rectification and delivery of active particles

We use moving light patterns to control the motion of Escherichia coli bacteria whose motility is photoactivated. Varying the pattern speed controls the magnitude and direction of the bacterial flux, and therefore the accumulation of cells in up- and down-stream reservoirs. We validate our results with two-dimensional simulations and a 1-dimensional analytic model, and use these to explore parameter space. We find that cell accumulation is controlled by a competition between directed flux and undirected, stochastic transport. Our results point to a number of design principles for using moving light patterns and light-activated micro-swimmers in a range of practical applications.

Koumakis, N. (2019). Dynamic optical rectification and delivery of active particles, [image]. https://doi.org/10.7488/ds/2603.