Ag nanoparticle/polydimethylsiloxane composite films for high-sensitivity strain gauge applications

This paper presents a type of Ag/polydimethylsiloxane (Ag/PDMS) nanocomposite material for use in strain gauge element applications. In these elements, the Ag nanoparticles work as conductive elements by electron tunneling and the PDMS forms the tunneling dielectric structure. In our experiments, the piezoresistance and piezocapacitance characteristics of these Ag/PDMS composites have been studied under applied strain/stress. From the results, the gauge factors for piezoresistance and piezocapacitance can reach up to 153 and 224, respectively. Also, when acting as strain elements, the Ag/PDMS composites show fine levels of repeatability and stability. The results given here prove that the material can be used to form a new type of high-sensitivity element for sensor applications. The detection method used for the sensor signals also offers diversity by including both piezoresistance and piezocapacitance.