Parylene-based electrochemical-MEMS force sensor array for assessing neural probe insertion mechanics

We present the first use of a Parylene-based electrochemical-MEMS (EC-MEMS) sensor array for instrumentation of ceramic-based neural electrode probes. The sensor array consists of a liquid-filled Parylene-based microchannel and an array of enclosed electrodes that monitor local variations in impedance during mechanical deformation of the channel. The array provides real time measurement of out-of-plane interfacial forces produced directly on the electrode shank surface (<;5 mm²) during insertion of the probe. We demonstrate the ability to examine the relative force distribution of interfacial forces produced on the shank surface during insertion, thereby providing a clearer understanding of probe insertion mechanics. Our approach enables, for the first time, robust mechanical instrumentation of electrode shanks providing a means for assessing the poorly understood interfacial mechanics between neural probes and tissue.