A Novel Smart Shoe Insole for Gait Analysis

This paper introduces a novel, robust, and electrically noise-resistant footwear sole using piezoelectric sensors for gait analysis. While numerous piezoelectric footwear energy harvesters have been reported in the literature, they have all faced a common challenge—the low mechanical strength of piezoelectric sensors required to withstand the weight of a human. Our results demonstrate that coating the piezoelectric sensors with silicone rubber not only significantly enhances the strength of the designed sole against mechanical loads but also the optimal value of the hardener-to-resin ratio, resulting in remarkable improvements in sensor efficiency. An electrical circuit is implemented for data acquisition in the test setup and revealed that the silicone coating of the piezoelectric sensors contributes to a reduction in noise levels in the output signals. Various tests have been conducted to investigate the pressure distribution on the foot s sole and its temporal sequence. Additionally, the system accurately detects ankle-twisting incidents, showcasing its potential to diagnose joint-related issues. This innovative sole design holds promising applications, including real-time gait analysis, sports performance tracking, pressure mapping, and rehabilitation purposes.