Characterization of a micromachined planar patch clamp for cellular electrophysiology

We have fabricated planar patch-clamp substrates suitable for use in cellular electrophysiology. The substrates are a base component of a larger automated dose-response measurement system. Substrates with cell-patch-site apertures ranging from 0.5 mum to 11 mum were fabricated using standard MEMS techniques. The resistance of the cell-patch-site apertures and substrate capacitance were measured using impedance spectroscopy. The resistance of the cell-patch sites ranged from 0.2 MOmega to 47 MOmega for apertures ranging from 12 mum to 0.75 mum. The substrate capacitance was 17.2 pF per mm(2) of fluid contact area for substrates with a 2-mum thick layer of silicon dioxide. It was found that the electrical properties of the substrates are acceptable for use in electrophysiological applications.