Laser-Induced Graphene for Screen-Printed Strain Sensors

The rapid progress in wearable electronics necessitates the development of high-performance flexible strain sensors. This research presents a significant breakthrough in the large-scale production of laser-induced graphene (LIG) through the utilization of laser direct writing technology. The subsequent conversion of LIG into screen printing ink enables the creation of the patterned LIG electrode, facilitating the fabrication of a flexible strain sensor with exceptional performance. This screen-printed LIG strain sensor demonstrates remarkable sensitivity, indicated by a gauge factor (GF) of 100.5, along with impressive response and recovery times of 0.25 and 0.29 s, respectively. Moreover, the sensor exhibits outstanding cyclic stability, enduring over 2000 stretching-release cycles. Notably, this strain sensor accurately captures and monitors various human movements, including finger bending, vocal vibration, wrist flexion-extension, and pulse detection. Leveraging the inherent simplicity, cost-effectiveness, and reliability of the screen printing process for LIG electrodes, our approach enables efficient and stable mass production, thereby enhancing commercial feasibility. In comparison to traditional graphene-based strain sensors, the screen-printed LIG strain sensor offers the advantage of controllable electrode shapes, allowing for seamless integration onto a diverse range of flexible substrates to meet compatibility requirements and achieve modular integration. As a result, our flexible screen-printed LIG strain sensor holds immense potential for transformative applications in the field of flexible wearable electronic devices.