A silicone-based soft matrix nanocomposite strain-like sensor fabricated using Graphene and Silly Putty[formula omitted

Abstract

Off-the-shelf planar strain gauges are ubiquitous and are generally designed for materials with a large elastic modulus such as steel or aluminum. Correspondingly, the strain gauges themselves are stiff and do not deform substantially under applied stress. Pairs of this type of strain gauge are typically used in a Wheatstone bridge circuit allowing the measurement of very small changes in resistance due to the changes in sensing element cross-sectional area to be measured. However, their use with softer low-modulus materials is limited due to the larger elastic deformations involved. The conductive property of graphene is leveraged to produce a different type of strain sensor that is sensitive yet also capable of significant elastic deformation. The graphene is dispersed in a silicone-based polymer matrix such that the deformation induces a change in resistance that can be measured using a voltage divider circuit. The target application for which this sensor is developed is to measure strain in a pressurized length of soft Tygon® tubing which is often used in pumping fluids through microfluidic devices. However, the silicone-based graphene polymer can easily be applied to a variety of other shapes and soft materials.