Surface Bonding Graphene-Based Elastomeric Sensor: Preliminary Characterization of Adhesion Strength

Abstract

This research intends to propose a structural integration methodology for a strain sensor based on nano-filled elastomer and its preliminary bonding strength characterization. To provide a good strength adhesion onto a structural component, a special mould was designed, made of Acrilonitrile butadiene styrene (ABS) material and realised with a 3D printing. This specific texture provided the lower surface of the elastomer (PDMS-matrix) with a special micro voids allowing for the adhesive penetration. The electrodes were made by simple conductive paste. To have a chemically compliant coupling between the elastomer and this paste, an off-the-shelf cheap neutral silicone was used. This paste was then made conductive by adding a low-cost graphite powder, obtained from a pencil lead. The test was realized with an aluminium beam in cantilever configuration. The load were applied at the free edge by means of calibrated masses of increasing weights. For each mass, the values of tip displacement and the resistance provided by the nano-filled elastomer and a reference strain gauge were logged for a set of 10 cycles. Obtained data clearly revealed that, all sensors exhibit coherent readouts with respect to the reference strain gauges and a quasi linear sensitivity curve in the whole range.