Stretch Tunable Active Frequency Selective Fabric for Dynamically Switchable Bandstop and Transparency

Developing zero‐power and wearable electromagnetic functional fabrics is essential for adaptive communication and shielding in complex environments. Here, we propose a stretchable active frequency selective fabric, fabricated by screen printing, that achieves bistable switching between bandstop and broadband transparent states through fracture‐induced topological reconfiguration. In its initial state, the periodic cross‐shaped conductive units produce a strong bandstop response at 10.5 GHz (−22.48 dB, quality factor 7.5). When stretched to 15% strain, conductive pathways rupture into a disordered network, eliminating resonance and enabling nearly transparent transmission (<0.2 dB across 4–14 GHz). Upon release, the conductive structure self‐reconstructs, restoring the original bandstop performance with excellent cycling durability. Unlike conventional diode‐ or bias‐driven active frequency selective surface, the proposed active frequency selective fabric requires no external circuits or energy input, offering a scalable, lightweight, and flexible solution. These attributes highlight its potential for wearable electromagnetic shielding, sustainable communication devices, and next‐generation adaptive smart fabrics.