Parylene-based Electrochemical-MEMS Transducers

Abstract—We report the design, fabrication, and charac-terization of electrochemical microelectromechanical systems (EC-MEMS) devices featuring encapsulated fluid as the basis for transduction. Parylene microstructures, including discrete chambers (square or circular geometry), are utilized as physi-cal transducers for electrochemically mediated liquid impedance transduction of physical phenomenon such as contact and force. Parylene-based EC-MEMS technologies uniquely leverage advan-tages in size (< 500 μm diameter), packaging (no hermetic pack-aging necessary), power (nanowatts to microwatts), and flexibility to address the physical sensing requirements of in vivo applica-tions. Robust EC impedance (EI) sensor responses (up to 20% from base-line) and discrimination of 200-nm chamber deflections were possible using the EI transduction technique. Additional transducer configurations enabling electrolysis-based out-of-plane actuation and biomimetic mechanotransduction in microfluidic channels are also presented. [2010-0157] Index Terms—Biomimetic, contact sensor, electrochemical microelectromechanical systems (EC-MEMS), EC sensing, E