Laser-Induced Corrugated Graphene Films for Integrated Multimodal Sensors

Microstructures play a dominant role in flexible electronics to improve the performance of the devices, including sensitivity, durability, stretchability, and so on. However, the complicated and expensive fabrication process of these microstructures extremely hampers the large-scale application of high-performance devices. Herein, we propose a novel method to fabricate flexible graphene-based sensors with a 3D microstructure by generating laser-induced graphene (LIG) on the 3D printed polyether ether ketone corrugated substrate, which is referred to as CLIG. Based on that, two integrated piezoresistive sensors are developed to monitor the precise strain and pressure signals. Contributed to the 3D corrugated graphene structure, the sensitivities of strain and pressure sensors can be up to 2203.5 and 678.2 kPa^-1, respectively. In particular, the CLIG-based strain sensor exhibits a high resolution to the microdeformation (small as 1 μm or 0.01% strain) and remarkable durability (15,000 cycles); meanwhile, the pressure sensor presents a remarkable working range (1-500 kPa) and fast response time (24 ms). Furthermore, the CLIG-based sensors provide a stable data source in the applications of human-motion monitoring, pressure array, and self-sensing soft robotic systems. High accuracy allows CLIG sensors to recognize more subtle signals, such as pulse, swallowing, gesture distinction of human, and movement status of soft robotics. Overall, this technology shows a promising strategy to fabricate high-performance sensors with high efficiency and low cost.