A stretchable flexible strain sensor with high sensitivity and fast response fabricated by embedded 3D printing of the hybrid polydimethylsiloxane/conductive carbon paste composites

Abstract Flexible strain sensors are widely used in the fields of human motion monitoring, electronic skin, and soft robotics. In this work, to satisfy the demand for high‐sensitivity, low‐cost, and fast‐response flexible strain sensors for these fields, embedded 3D printing (E‐3DP) technology is employed to fabricate highly sensitive and fast‐responding flexible strain sensors. The effects of conductive carbon paste concentration and printing process parameters by establishing the E‐3DP system on the piezoresistive behavior of the sensor were investigated. The results show that the gauge factor of the strain sensor is about 36.1 and 247.67, under the strain of 0%–40% and 40%–45%, respectively. Its response/recovery time is about 250/350 ms. On this basis, the sensor can also accurately sense and distinguish the motion in distinct parts of the human body, demonstrating that the flexible strain sensor manufactured by the method possesses the potential to be widely used in the fields of human motion monitoring, electronic skin, and soft robotics.