The enhancement of sensitivity and response times of PDMS-based capacitive force sensor by means of active layer modification

Abstract

In this work, sensitivity and response times of PDMS-based capacitive force sensors are enhanced via the modifications of the PDMS layer. Two modifying approaches are proposed; (i) change PDMS’s (elastomer:curing agent) ratio and (ii) adding conductive polymer PEDOT:PSS into the PDMS layer. The change of PDMS (elastomer:curing agent) ratio from (10:1) to (30:1) increases the sensitivity from 0.4 ± 0.08 to 0.72 ± 0.23 kPa−1 (+80%) but it does not significantly affect the response/recovery times. In addition, by adding 1% wt. of PEDOT:PSS to PDMS (30:1), the further increment of sensitivity from 0.72 ± 0.23 to 1.44 ± 0.17 kPa−1 (+100%) and the shorter response time from 1.59 ± 0.02 to 0.45 ± 0.03 s (−72%) are observed. The mechanical and electrical studies reveal that the change of PDMS (elastomer:curing agent) ratio and the adding of PEDOT:PSS to PDMS layer result in the modification of PDMS’s deformability and the increase of charge transportation, leading to the enhancement of sensing characteristics of the sensors.

PDMS Microfabrication and Design for Microfluidics and Sustainable Energy Application: Review

“…With integrating the laser processing, the advantages of reducing the cost and shortening the process time can be achieved. Furthermore, researchers have also focused on the triboelectric/dielectric properties, including a variety of sensors [40][41][42][43][44][45][46][47][48][49] produced by composite structures from PDMS and other materials. Triboelectric properties are the main reason for research on TENG in recent years.…”