An area/power efficient electrode-matched neural-spike detector embedded in implantable 256-channel MEA

Abstract

A compact area/power efficient electrode-matched neural-spike detector (NSD) is proposed to provide an implantable multi-electrode array (MEA). A correlation scheme with only the input sampling capacitors makes an area reduction, and the recording of neural-spike events enables a power reduction, showing 0.0044 mm2 and 0.55 μW. Together with proposed NSD, an implantable 256-channel MEA is fabricated. The electrical measurement results show that the NSD achieves an input-referred noise of 10.1 μVrms with 1 kHz to 10 kHz bandwidth, providing NEF/PEF/AEF of 1.71/5.28/0.0044, respectively, and CMRR of 67.5 dB. It shows ×7.5/×1.6 area/power improvements, compared to previous state-of-the-art NSDs. The fabricated implantable MEA is demonstrated by cell-cultured and brain-sliced experiments.