Micro-multi-probe electrode array to measure neural signals

A multi-electrode array (MEA) with 16 channels was designed to record simultaneously the velocity of conduction of neurons in a measurement system for bio-medical applications. MEA were fabricated with MEMS technology on a silicon-on-insulator (SOI) wafer, which controls the thickness of the probe effectively. All used probes have length 3 mm and width 100 μm. The thickness of the probe, 25 μm, was defined by the thickness of the device layer on the SOI wafer. The multiple probes with a 16-site recording electrode array have been manufactured; their strength was tested with a force gauge and their electrical performance was tested with an impedance measurement system. The readout circuitry comprises an array of 16-site preamplifiers fully integrated on a chip that is capable of signal processing to improve the signal-noise-ratio (SNR). To demonstrate the capability, multiple neural signals were recorded simultaneously with all electrodes from each separate probe. To verify its capability of measuring neural signals, the MEA was used to measure these signals from the electrophysiology system of crayfish. The velocity of neural conduction recorded with a fabricated MEA is shown, and is comparable with a measurement with a traditional glass pipette. The MEA for recording neural signals would be improved in further development.