Flexible Smart Insole and Plantar Pressure Monitoring Using Screen-Printed Nanomaterials and Piezoresistive Sensors
Jaeho Lee, Jimin Lee, Yoon Jae Lee, Hodam Kim, Youngjin Kwon, Yunuo Huang, Matthew Kuczajda, Ira Soltis, Woon‐Hong Yeo
Abstract
High Resolution Image Download MS PowerPoint Slide Individuals experiencing gait dysfunction─such as the elderly, those with peripheral nervous system damage, or individuals with Parkinson’s disease─face a heightened risk of physical injury due to imbalanced weight distribution. Despite recent advancements in wearable movement trackers, there remains a significant need for a reliable long-term plantar pressure monitoring system. While some existing devices measure pressure characteristics, many are hindered by limitations in spatial resolution, sensitivity, and the presence of bulky peripherals. Here, we introduce a flexible smart insole system that integrates screen-printed nanomaterials to create a high-density piezoresistive sensor array, enabling accurate plantar pressure measurement during daily activities. To ensure scalable and cost-effective manufacturing, we utilize a screen-printing method to fabricate 173 carbon-based sensors directly onto a flexible insole circuit. The printed sensors demonstrate a remarkable sensitivity of −0.322 kPa –1, surpassing previous benchmarks. When combined with a wearable mobile communication circuit, this system offers a comprehensive analysis of the user’s plantar pressure distribution. Experimental studies conducted with human subjects showcase the smart insole’s real-time monitoring capabilities in common daily ambulation scenarios. The integration of high spatial resolution, exceptional sensitivity, and a fully mobile wearable system holds significant promise for enhancing outcomes across various applications, from healthcare to athletics.