Unveiling the potential of direct graphene patterning via mechanical exfoliation for wearable strain sensors

Abstract

Graphene-based strain sensor was fabricated through the exfoliation of graphene into a desired shape from a graphite sheet using a self-designed mask. This study aims to demonstrate a facile and environmentally benign method for direct graphene patterning into strain sensors using a single-step mechanical exfoliation process at room temperature. This cost-effective approach avoids chemical treatments and complex equipment, resulting in a highly sensitive and flexible strain sensor. The presence of graphene was confirmed via Raman spectroscopy followed by microstructural studies using X-ray diffraction and scanning electron microscopy. The sensor demonstrated rapid response and recovery times of 170 ms and 175 ms under tensile strain, and 115 ms and 70 ms under compressive strain, respectively. It exhibited excellent stability and durability, maintaining consistent performance over 1000 bending cycles. Furthermore, its integration into motion-monitoring systems effectively captured wrist and knee movements with high sensitivity, showing up to an 80 % resistance change for a 90° knee bend. These results highlight the potential of this sensor for applications in wearable electronics, healthcare, sports performance, and rehabilitation, offering a scalable and efficient solution for real-time strain detection.