Microfabrication of biocompatible cuff electrodes for upper-limb neuroprosthesis

This paper compares two easy, low-cost methods for the microfabrication of neural cuff electrodes. Cuff electrodes are designed to acquire neural signals directly from nerve fascicles, with subsequent use of the signals to control hand grips in the upper-limb neuroprosthesis. Biocompatible materials, such as Au and PDMS are typically used to make electrodes suitable for implants. We studied techniques to transfer etched gold patterns to a PDMS film to produce soft, flexible PDMS-Au cuff electrodes. The gold tracks were fabricated on a silicon wafer using standard photolithography and then transferred to the PDMS substrate by two different methods, a chemical-free transfer and an MPTMS transfer method. In both methods, we compared some relevant tuning parameters, such as curing temperature and ratio of the PDMS, to improve the Au-pattern transfer. We achieve the complete transfer of Au onto PDMS using the MPTMS method.