Surface micromachined and integrated capacitive sensors for microfluidic applications

Abstract

We have demonstrated an entire series of capacitive sensors using a multi-layer parylene/photoresist surface micromachining technology. The developed sensors are designed for total integration into parylene-based microfluidic systems for real-time system monitoring. Sensors have been demonstrated for the following applications: in-line pressure sensing (range: 0-35 kPa, resolution: 0.03 kPa); liquid front position and/or volumetric measurements (range: 0->50 pL, resolution: <5 pL); and dielectric measurements, which can be used to deduce fluid properties such as liquid composition. The reported sensor technology demonstrates versatility, high sensitivity, small footprints, and easy integration.