Flexible BioMEMS devices enabled by micromachining of plasma-polymerized fluorocarbon

Abstract

Microelectromechanical systems for biological purposes (BioMEMS) have shown huge potential for diagnostics, medical treatment or even augmenting certain body functions in humans. This is enabled by the high level of integration, manufacturing precision and high throughput of fabrication techniques in sophisticated semiconductor industries. For minimally invasive devices, mechanically compliable polymeric materials are widely used, like SU-8, polyimide and parylene C, which have good biocompatibility but are difficult to be integrated with standard fabrication processes in semiconductor industries, therefore limiting the production throughput and complexity of device architecture. In this work we present various micromachining techniques of plasma-polymerized fluorocarbon (PPFC), which is a feasible polymeric material acquirable by plasma etching systems. Due to its excellent chemical stability, PPFC is compatible with standard fabrication techniques like plasma etching, photolithography and deposition of thin metal films, which enable the functionalization of PPFC-based platforms for BioMEMS devices. The processing parameters have been discussed, and structures like high aspect ratio nanopillars and PPFC membranes are demonstrated. As a proof of concept, flexible free-standing microelectrode arrays are fabricated. Since PPFC resembles the physiochemical properties of fluorocarbon, which is recognized by USP Class VI standards, we expect PPFC-based platform to be a strong candidate for development of various BioMEMS devices, like biological implants, tissue engineering, neuroprosthetic electrodes, brain-machine interfaces, etc.