Carbon-based flexible strain sensors: Recent advances and performance insights in human motion detection

Abstract

Flexible strain sensors have evolved from basic mechanical strain gauges to advanced systems, playing a vital role in monitoring structural health and human body movements across a range of applications including healthcare, sports, and rehabilitation. These sensors, particularly those made from carbon-based materials like graphene and carbon nanotubes, offer high sensitivity and durability by converting mechanical deformations into measurable electrical signals through a combination of flexible substrates and conductive layers. Wearable devices and IoT systems, utilizing wireless communication protocols such as Low Power Bluetooth (BLE), Wi-Fi, Near Field Communication (NFC), and Radio Frequency Identification (RFID), enable real-time monitoring and tracking, with battery-less RFID tags providing an efficient solution for wireless body movement tracking. The integration of AI, especially through machine learning and deep learning, has further enhanced wearable sensor technology by enabling advanced data analysis and continuous monitoring with minimal supervision. Despite significant advancements, challenges remain in the fabrication and daily integration of these sensors, which require innovative approaches in materials and AI-driven data processing to develop reliable, high-performance sensors for everyday use, expanding their potential in health monitoring and human–machine interfaces.