We use moving light patterns to control the motion of {\it Escherichia coli} bacteria whose motility is photo-activated. 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. We articulate design principles for using moving light patterns and light-activated micro-swimmers to achieve particular experimental goals.
@article{arxiv.1811.09133,
title = {Dynamic optical rectification and delivery of active particles},
author = {Nick Koumakis and Aidan T. Brown and Jochen Arlt and Samuel E. Griffiths and Vincent A. Martinez and Wilson C. K. Poon},
journal= {arXiv preprint arXiv:1811.09133},
year = {2018}
}