Development of a Novel and Flexible MWCNT/PDMS Based Resistive Force Sensor

Abstract

A novel multi-walled carbon nanotubes (MWCNTs) and polydimethylsiloxane (PDMS) based resistive force sensor was fabricated using screen printing and laser-pattering processes for detecting various applied forces. The electrodes for the force sensor was developed by depositing silver (Ag) ink on a flexible polyimide substrate using screen printing process. The honey comb structured and unstructured active sensing layers of the force sensors were prepared by laser patterning the MWCNT/PDMS composite. A surface roughness of $1.65 \pm 0.10 \mu\mathrm{m}$ and $0.43 \pm 0.08 \mu\mathrm{m}$ was measured for the printed electrodes and MWCNT/PDMS, respectively. The capability of the printed sensor was investigated by subjecting it to varying forces ranging from 0 N (no force) to 20 N. The results demonstrated an overall relative resistance change of ~19% and ~5% for the force sensors with honey comb structured and un structured active layers. The fabrication method and sensor responses are analyzed and presented in this paper.