OPTICAL FEEDBACK CONTROL/ANALYSIS OF PHOTOREACTIVE EUGLENA CELLS SWIMMING IN MICRO-AQUARIUMS

Abstract

We present a two-dimensional (2D) optical feedback system to control/analyze photoreactive flagellate microbes confined in mm-scale microfluidic channels (micro-aquariums). The system uses a liquid-crystal (LC) projector to induce the phototaxis reactions of microbes, thus arbitrary 2D patterns with variable colors and intensities can be projected onto microaquariums. We demonstrate that the density and position of Euglena cells in micro-aquariums are controlled by the system dynamically and flexibly. Transient steps in the photophobic reactions of Euglena were observed with the system with a time resolution of several ten ms, showing a complex photoreaction mechanism of Euglena.