Flexible three-axis tactile sensor based on double-layer electrospun polyimide nanofiber membrane

The construction of multi-modal human-machine interaction system makes computer more and more adaptable to human. A flexible three-axis tactile sensor based on a double electrospun polyimide (PI) nanofiber membrane as a dielectric layer has been proposed to sense the multi-axis forces like normal and shearing. A range of thicknesses of double PI nanofiber membranes were explored to optimize the dielectric layer. The sensor with such a dielectric layer exhibited high sensitivity (average sensitivities of the force sensor units were 1.5370 N−1, 0.6620 N−1 and 0.6960 N−1, respectively for the normal force, X-axis, and Y-axis shear forces), wide scale range (0–8 N, 0–3 N, 0–3 N, respectively), quick response (87.5 ms) and good cyclic stability (>10,000 cycles). A typical 4 × 4 sensor array could be used to accurately sense and then designed to achieve multiple combination control modes. A three-axis tactile force sensor may advance artificial skin and robotic applications such as human-machine interaction and disability rehabilitation in the future.