Shape-adaptive and recyclable radio-frequency devices based on polymer with variable stiffness

Radio-frequency (RF) devices are an indispensable component in wireless communication systems. Developing high-strength, cost-effective RF devices with good performance on irregular surfaces is very important but remains highly challenging. Here, we report a dynamic variable-stiffness polymer with high mechanical strength, shape-memory behavior, and recyclability by introducing multiple dynamic cross-linking interactions (coordination bonds, dipole-dipole interactions, and chain entanglements). Leveraging the unique characteristics of the polymer, we fabricate several shape-adaptive RF devices and a backscatter communication system through the ultra-low-cost planar manufacturing process. These RF components can be fitted to various irregular surfaces when heated and retain their shape with high mechanical strength after cooling. In addition to simultaneously offering mechanical robustness and conformal capability, these devices possess high electromagnetic performance as well as self-healing and recyclable properties. We believe that such shape-adaptive RF devices hold great potential in robots, intelligent aircraft, wearable electronic systems, and more.