Geometry-Engineered Porous Graphene Microheaters for Efficient Electrothermal Heating, Temperature Sensing, and Deicing Applications

Abstract

Flexible microheaters are critical components for localized thermal management in wearable and soft electronic systems; however, achieving efficient electrothermal performance while maintaining multifunctionality remains challenging. Here, we report geometry-engineered porous graphene microheaters fabricated through a single-step maskless laser writing process on polyimide substrates. Finite-element simulations and experimental investigations reveal that heater geometry plays a decisive role in governing current distribution and Joule heating behavior. In particular, smooth-cornered microheater architectures suppress current crowding, resulting in improved current uniformity, reduced resistive losses, and enhanced electrothermal performance. The optimized geometry achieves a maximum temperature of ∼117 °C at 5 V, compared to ∼87 °C for conventional sharp-cornered designs. Furthermore, optimization of laser processing conditions and metal-assisted fabrication produces highly conductive porous graphene with low defect density (ID/IG ≈ 0.24) and low sheet resistance (∼10 Ω sq–1), enabling rapid heating with a maximum ramp rate of ∼13 °C s–1. Beyond thermal actuation, the same device architecture functions as an intrinsic temperature sensor, exhibiting high linearity (R2 ≈ 0.99), a sensitivity of ∼0.069 % °C–1 over 30–100 °C, rapid response (∼2.1 s), and stable operation under repeated bending. The optimized porous graphene heater also demonstrates efficient deicing performance, achieving complete ice removal within ∼240 s with a heat flux of 115.6 mW cm–2 and an energy consumption of 27.7 J cm–2. These results establish geometry and process engineering as effective strategies for enhancing porous graphene microheater performance and provide a scalable platform for integrated thermal actuation and temperature monitoring in flexible electronic systems.