Fig. 3

Three different direct-current EStim systems. a Direct current is applied between two metallic electrodes. b Two agar salt bridges connect culture medium to saturated solution of inert salt and delivery current. This system prevents cells from exposing directly to faradic products. c Microfluidic EStim chamber consist of a pair of electrodes, an inlet, an outlet and a fluidic channel. Cells are loaded through the inlet, driven to middle of the electrodes, exposed to EStim, and driven to outlet. The small cross-section of channel reduces the amount of toxic products