Plantar Pressure Monitoring System Based on a Flexible Pressure Sensor Array for Human Walking Feature Recognition

Flexible pressure sensors have advantages in human walking feature recognition because of their good flexibility and sensitivity. In this article, a flexible pressure sensor with stable mechanical properties and high sensitivity was designed based on the single-layer interdigital electrode made by the screen-printing process and the piezoresistive layer with a pyramidal microstructure made by the double inversion method. This structural design improves the sensitivity and wear resistance of the flexible pressure sensor and reduces the difficulty of packaging. The prepared flexible pressure sensor shows a higher sensitivity (−0.886 kPa $^{-{1}}$ ), a wider measurement range (0–180 kPa), a faster response time (80 ms), a lower detection pressure (11.8 Pa), and excellent durability. Then, a human plantar pressure monitoring system based on the flexible pressure sensor array was constructed to reflect the changes in human plantar pressure. Also, this monitoring system can recognize five types of human walking features through the support vector machine (SVM) algorithm. This work proves that the prepared flexible pressure sensor can be used as a flexible wearable device to accomplish complex tasks, such as recognizing human walking features, and it shows great potential in the field of health diagnosis.