An intelligent insole based on wide-range flexible pressure sensor

In this paper, an intelligent insole that contains five wide-range flexible capacitive pressure sensors is developed. The output signal of these five sensors is collected and processed by a portable microprocessor system, which is then transmitted to a cloud platform via a Wi-Fi module. The ensuing data visualization is constructed with a WeChat mini-program. The wide-range flexibility is achieved by employing composition materials with a high pressure-sensitive effect. A novel approach is proposed to fabricate flexible pressure-sensitive dielectrics, thereby significantly enhancing the sensitivity and detection range of pressure sensors. The fabrication process involves utilizing polydimethylsiloxane (PDMS) as a flexible substrate, incorporating nano-iron powder and polyvinylidene fluoride as sensitizing materials, and applying an external magnetic field to control the distribution of iron nanoparticles during the curing process of PDMS. Furthermore, a motion detection system tailored for these flexible sensors is developed. By integrating sensor networks with Internet of things technology, the application potential of wide-range flexible pressure sensors in kinematics and medical rehabilitation fields can be effectively realized.