Green Manufacturing of Flexible Sensors with a Giant Gauge Factor: Bridging Effect of CNT and Electric Field Enhancement at the Percolation Threshold

Toxic organic solvents are commonly used to disperse nanomaterials in the manufacturing of flexible conductive composites (e.g., graphene-PDMS). The dry-blended method avoids toxic organic solvent usage but leads to poor performance. Here, we proposed an innovative manufacturing method by adapting the traditional dry-blended method, including two key steps: minor CNT bridging and high-frequency electric field enhancement at the percolation threshold of graphene-PDMS. Significant improvement was achieved in the electrical conductivity (1528 times), the giant gauge factor (>8767.54), and the piezoresistive strain range (30 times) over the traditional dry-blended method. Further applications in measurements of culturing rat neonatal cardiomyocytes and mouse hearts proved that the proposed method has great potential for the manufacturing of nontoxic flexible sensors.