Implantable medical drug delivery systems using microelectromechanical systems technology

A unique design of an implantable micropump for medical drug delivery systems was proposed. Three pump chambers (/spl phi/12 mm in diameter) are individually actuated by each bulk PZT (lead zirconate titanate) disk in a peristaltic motion. This peristaltic motion drives the fluid forward. A 70 mm/spl times/35 mm/spl times/1.63 mm micropump was fabricated using MEMS fabrication technology. Three 90 /spl mu/m deep and 12 mm in diameter micropump chambers were connected by a 2 mm long and 10 mm wide flow passage. To pump drug at a target rate of 10 /spl mu/L/min, a 12 mm in diameter and 80 /spl mu/m thick silicon membrane of each pump chamber was actuated at 0.5 Hz in a peristaltic mode. The state-of-the-art fabrication technology was applied to the proposed micropump. The deep trench reactive ion etching, anodic bonding, radio frequency (RF) sputtering, STS etching and oxidation deposition were employed. A micropump was successfully fabricated to prove the concept.