Multidirectional strain-insensitive stretchable RF electronics.

Abstract

Stretchable radio-frequency (RF) electronics underpin emerging wearable systems for body-centric communication, continuous health monitoring, and wireless power transfer. However, on-body stretchable antennas undergo multidirectional in-plane strain during natural motion, which detunes resonance and destabilizes wireless links. Existing strain-insensitive designs are typically effective only along prescribed loading directions and often compromise radiation performance. Here, we establish a systematic directional mechano-electromagnetic analysis framework for resonant planar antennas and introduce a dual-port multidirectional strain-insensitive antenna (DP-MSiA), whereby strain-insensitive resonance (shift ≤ 40 MHz at 2.45 GHz) is achieved under up to 45% strain across diverse in-plane directions. Based on the stable resonance and high realized gain of the DP-MSiA, we demonstrate strain-insensitive wireless energy harvesting with rectifiers under in-plane strain of varying direction and magnitude, as well as a strain-robust on-body communication system that sustains stable multimodal health-data transmission during natural motion. Our work opens new opportunities for creating deformation-insensitive electronics and enables integrated functionalities in wearable and embodied systems.