Shape memory alloy microactuation of tf-LIFEs: preliminary results

In this paper, a new approach aimed at improving the performance of intraneural longitudinal interfaces (tf-LIFEs) with the peripheral nervous system (PNS) is presented. Our goal is to develop a movable interface by embedding microactuators into the flexible tf-LIFEs structure. In this way, the optimal position of the electrical contacts can be searched inside the PNS and lost connections with neural cells could be replaced. For this purpose a thin film of shape memory alloy (tf-SMA) was selected. A multisegmented SMA was realized and embedded between two polyimide thin films in order to simulate the tf-LIFE structure. Thermal evaluation, fabrication procedure, the first characterization and preliminary experimental results of the new movable interface are described in the manuscript. A total controllable stroke of about 10 [micro]m was obtained for the presented prototype. Index Terms--Biorobotics, intraneural interfaces, neuroprostheses, shape memory alloys, tf-LIFE.