We present a facile method to prepare flexible, transparent, biodegradable, and fast resistive heaters by applying silver (Ag) nanowires onto fractal-like leaf skeletons. The fractal-like structure of the leaf skeleton maximizes its surface area, improving the transfer of heat to its surroundings and thus making the heater fast, without compromising transparency. Ag ion layer on the leaf skeleton helps to conformally cover the surface with Ag nanowires. The sheet resistance of the heater can be controlled by the loading of Ag nanowires, without sacrificing the optical transmittance (~80% at 8 Ω sq⁻¹). The heating is uniform and the surface temperature of a 60 mm × 60 mm heater (8 Ω sq⁻¹) can quickly (5–10 s) raise to 125 °C with a low voltage (6 V). The heater displays excellent mechanical flexibility, showing no significant change in resistance and heating temperature when bent up to curvature of 800 m⁻¹. Finally, we demonstrate the potential of the bioinspired heater as a thermotherapy patch by encapsulating it in a biodegradable tape and mounting it on the human wrist and elbow. This study shows that fractal-like structures from nature can be repurposed as fractal designs for flexible electronics.

我们提出了一种简便的方法，通过将银（Ag）纳米线应用于分形的叶片骨架上来制备灵活，透明，可生物降解和快速的电阻加热器。叶片骨架的分形结构使表面积最大化，从而改善了热量向周围环境的传递，从而使加热器快速运转，而又不影响透明度。叶骨架上的银离子层有助于用银纳米线保形覆盖表面。加热器的薄层电阻可以通过负载Ag纳米线来控制，而不会牺牲光透射率（在8Ωsq ^-1时约为80％）。加热均匀且表面温度为60 mm×60 mm加热器（8Ωsq ^-1）可以在低压（6 V）下快速（5–10 s）升至125°C。加热器具有出色的机械柔韧性，弯曲至800 m ^-1的曲率时，电阻和加热温度均无明显变化。最后，我们通过将生物启发式加热器封装在可生物降解的胶带中并将其安装在人的手腕和肘部上，来证明其具有作为热疗贴片的潜力。这项研究表明，来自自然界的分形结构可以重新用作柔性电子产品的分形设计。