Nepenthes-inspired Two-stage Structure for Laser-induced Graphene Piezoresistive Sensors with High Sensitivity and Wide Pressure Range
摘要
Typical tactile properties possessed by carnivorous plants like Nepenthes enable them to hunt and survive with the super-lubricity traps. Inspired by the two-stage structure of the unique peristome in Nepenthes, we propose a bionic manufacturing method includes UV laser patterning, CO2 laser-induced formation, lubricating oil infusion, and face-to-face encapsulation steps, to fabricate high-performance Laser-Induced Graphene (LIG) piezoresistive sensors. It was found that the Nepenthes-inspired electrode has a Water Sliding Angle (WSA) of 9.45° and shows self-cleaning properties for milk, cola, artificial plasma, and chemical solvents. The LIG-based electrode exhibits two-stage topological features, the microgrooves could provide efficient conductive paths, while the numerous micropores in graphene undergoes reversible compression and rebound under external pressure, thereby synergistically enhancing the resistance changes. Experimentally, the Nepenthes-inspired piezoresistive sensor demonstrates excellent sensitivities of 275.83, 93.23, and 4.28 kPa− 1 in linear pressure ranges of 0.15-36, 36–70, and 70–160 kPa, and keeps excellent signal repeatability and stability even after 6000 cycles under the pressure of 100 kPa. After integrating the self-developed wireless sensing system, this Nepenthes-inspired sensor could realize real-time monitoring of human respiratory status and joint movements, providing a green, low-cost, and easy-to-operate tech-route for the fabrication of wide-range, high-reliability wearable electronics.