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 (φ12 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 × 35 mm × 1.63 mm micropump was fabricated using MEMS fabrication technology. Three 90 μm 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 μL/mim, a 12 mm in diameter and 80 μm 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 mieropump. The deep trench reactive ion etching, anodic bonding, radio frequency (RF) sputtering, STS etching and oxidation deposition were employed. A mieropump was successfully fabricated to prove the concept.