Development and fabrication of highly flexible, stretchable, and sensitive strain sensor for long durability based on silver nanoparticles-polydimethylsiloxane composite

In this study, silver nanoparticles (AgNPs) conductive filler was attached on polydimethylsiloxane (PDMS) substrate to produce resistive-type strain sensors. The sandwich-structured-like PDMS covered AgNPs strain sensors (Ag-PDMS) and AgNPs modified PDMS composite strain sensors (Ag@PDMS) were fabricated by a drop-casting method. The effect of AgNPs loading such as 0.20 wt%, 0.25 wt%, and 0.30 wt% with PDMS was investigated and electromechanical performance were compared between Ag-PDMS and Ag@PDMS composite strain sensors. Based on the strain performance, the gauge factor of strain sensor fabricated with AgNPs loading with 0.25 wt% in PDMS (Ag-0.25@PDMS) composite revealed the gauge factor of 10.08 with a strain range of 70%, which demonstrated fast time response, good stretchability, durability, and repeatability. Ag-0.25@PDMS composite strain sensor fabricated in the present study is able to be used in finger motion detection, which indicates the capability of the sensor to be used for human body motion capture and other highly sensitive strain-sensing applications.