Micromachined tacks for retinal implant applications

To fasten an artificial retinal implant onto the epiretinal surface of the eye, our group has designed retinal microtacks. The microtacks were fabricated using two different micromachining techniques: 1) deep reactive ion etching (DRIE) and 2) ultra-high-precision micromilling. Metrology was performed on each microtack design following fabrication, measuring all critical and overall dimensions. Force measurement experiments were performed to determine the loads required to insert and remove each microtack design in a synthetic material. This was carried out to verify the validity of the new geometric features added to the microtack. Each experiment consisted of three programmed zones: Insertion, Hold, and Removal. The required displacement and velocity were determined for each zone dependent upon microtack design.