Fast voltage transients in capacitive silicon-to-cell stimulation detectedwith a luminescent molecular electronic probe

The capacitive stimulation of nerve cells from semiconductor chips is a pre requisite for the development of neuroelectronic devices. We report on the primary response of a cell membrane to a voltage step applied to oxidized s ilicon. It is observed with a luminescent voltage-sensitive dye. We find ex ponential voltage transients with a time constant of 1-5 mus. We assign the short response to an electrical decoupling by a thin film of electrolyte b etween oxide and membrane. The high-pass filtering of stimulation is a cruc ial constraint for the development of silicon-to-neuron interfaces.