The field-effect-addressable potentiometric sensor/stimulator (FAPS) - a new concept for a surface potential sensor and stimulator with spatial resolution

We, propose a new concept for a surface potential detector with high spatia l resolution and targe number of addressable points. The so-called field-ef fect-addressable potentiometric sensor/stimulator (FAPS) uses the ability t o control the resistance of FET-channels in semiconductor films with electr ic potentials. Making use of a grid-structure of perpendicular FET-channels and gate electrodes located below the FET-channels, it is possible to tune a single intersection into maximum sensitivity to electrical potentials lo cated above the FET-channel. By covering the surface above the FET-channels of a GaAs based FAPS with less than 100 nm PMMA, a bio-compatible interfac e could be created. This suggests the ability to record extracellular poten tials and apply extracellular stimuli to electrically excitable cells adher ent to the FAPS surface. (C) 1999 Elsevier Science S.A. All rights reserved .