Oxalis-Inspired, Two-Stage Interlocking of Bionic Micro-Jigsaw Structure in Laser-Induced Graphene-Based Pressure Sensor

Achieving high sensitivity over a wide response range is a major challenge for pressure sensors. Inspired by the unique geometry of natural oxalis leaves, we here propose a novel approach that includes preetching, growth, and transfer process to fabricate laser-induced graphene (LIG) with a two-stage (e.g., micro-jigsaw, micropore) structure. Experimentally, the oxalis-inspired pressure sensor exhibits a balanced sensitivity and response range (sensitivity of 15.8 kPa-1 in a linearity range of 0.5–5 kPa), due to the piezoresistive synergistic effects of two-stage structures. The mechanical interlocking between outer micro-jigsaw structures initiates huge resistance changes, whereas the inner shape-adaptive micropore structure plays a buffer role in the dynamic deformation, enabling reversible resilience over a wide working range. In combination with a self-developed all-in-one wireless transmission system, the oxalis-inspired pressure sensor is further assembled to monitor various health parameters such as tiny pulse, heartbeat, and voice, revealing a huge prospect in future wearable electronics.