Three dimensional SMA microelectrodes with clipping structure for insect neural recording

A microelectrode, with clipping structure for insect neural recording, was designed and fabricated by using a Shape Memory Alloy (SMA) thin film. The SMA thin films (TiNi: Titanium Nickel) are deposited by using RF magnetron sputtering, and patterned by HF-HNO/sub 3/ wet etching. The transformation temperatures of the SMA thin films measured 54/spl deg/C(A*) and 50/spl deg/C(M*). The SMA micro-electrode consists of one clipping structure (720 /spl mu/m/spl times/480 /spl mu/m) and two probes(600 /spl mu/m/spl times/70 /spl mu/m). The desired three-dimensional shape is given to the electrode by bonded wire while annealing. The SMA microelectrode can clip a nerve cord tightly, and neural activity from a living insect has been successfully recorded with this SMA microelectrode.