Polymer and carbon nanotube based sensors for pressure and strain measurements

In this paper we investigate the fabrication process of a novel polymer-based pressure/strain microsensor for use in pressure and strain measurements in medical environments. Our proposed flexible polymer-based pressure/strain microsensor is built using SU-8, and polyimide film (Kapton film). Single-walled carbon nanotube (SWCNTs) resistors are used as the sensing material. Here we report on our progress to date, and highlight the fabrication techniques that led us to investigate various sensor implementations, and their corresponding properties, and in particular sensitivity and reproducibility. The carbon nanotubes (CNTs) material is chosen because of its metallic and semiconducting properties and its nanoscale dimension. Published work has also shown it to provide high sensitivity and high reliability compared to Wheatsone-bridged piezoresistor sensors. This makes the CNTs ideal to be used in micro-sensor design, particularly in a medical implant scenario. We will also report on both the simulation and experimental results of this novel sensor during the prototyping stage.