A parylene bellows electrochemical actuator for intraocular drug delivery

Abstract—We present the first electrochemical actuator with Parylene bellows for large-deflection operation. The bellows di-aphragm was fabricated using a polyethylene-glycol-based sacrifi-cial molding technique followed by coating in Parylene C. Bellows were mechanically characterized and integrated with a pair of interdigitated electrodes to form an electrochemical actuator that is suitable for low-power pumping of fluids. Pump performance (gas generation rate and pump efficiency) was optimized through a careful examination of geometrical factors. Overall, a maximum pump efficiency of 90 % was achieved in the case of electroplated electrodes, and a deflection of over 1.5 mm was demonstrated. Real-time wireless operation was achieved. The complete fabri-cation process and the materials used in this actuator are bio-compatible, which makes it suitable for biological and medical applications. [2009-0095] Index Terms—Bellows, drug delivery device, electrolysis pump, intraocular implant. I