High-sensitive and stretchable resistive strain gauges: Parametric design and DIW fabrication

The main advantages of the direct ink write (DIW) printed strain gauge are capable of achieving both the high sensitivity and the large stretchability. The performance of the DIW-printed strain gauge is mainly determined by the design parameters and fabrication process. However, it is still a big challenge for parametric design and precision manufacturing of the DIW-printed strain gauge due to the lack of universal analytical model and optimized process parameters. Here we propose an analytical model for designing widely used sandwich-structure strain gauges with coating-filament-base layers on substrates. The resistive strain gauges with a commercial carbon paste are fabricated by the DIW technology on polyimide and aluminium alloy substrates, respectively. Both its high sensitivity and large stretchability are designed from the present analytical model and reproduced well by the DIW-based fabrication. Our analytical model and DIW-based fabrication will be of great help for designing and fabricating other sandwich-structure gauges.