A method for simultaneously preparing crack-based and composite-based PDMS strain sensors by mixing AgNWs and Ag microparticles

Abstract

Resistive-type strain sensors have been widely studied because of their high precision and convenient measurement. But the high sensitivity and large strain range of this kind of sensor conflict with each other. It is difficult to prepare a sensor with high sensitivity and a large tensile range at the same time. Here, we propose a method to use AgNWs/Ag microparticles (AgMPs) and PDMS to simultaneously manufacture two strain sensors with different principles, a crack-based sensor and a composite-based sensor. On the one hand, the crack-based sensor has a low detection limit of 0.5% strain and high sensitivity of GF ≈ 90 at the strain of 0 ∼ 50%. It is suitable for the detection of small strains and can detect throat vibration when speaking. On the other hand, the composite-based sensor has a large strain range of 0 ∼ 240% and excellent stability. After 1000 cycles of stretching-releasing at 50% strain, the resistance change rate remains unchanged. It is suitable for the detection of large strains. Moreover, the sensitivity and working range of the composite-based sensor can be adjusted by changing the ratio and total amount of AgNWs/AgMPs composites. It can accurately monitor the different bending angles of the elbow joint and a people’s walking status and pace. The strain sensor prepared by this method has great practical value in wearable devices and electronic skin.