Printable Liquid Metal-Textiles for Deformation-Insensitive and Electromagnetically Robust mmWave Devices

Millimeter-wave technologies are critical to the next generation of wireless body area networks, offering high data rates an d wide bandwidths. However, realizing mechanically robust and electromagnetically stable mmWave devices remains a significant challenge due to the high sensitivity of radio-frequency performance to conductive degradation under deformation. Here, we report a strategy to fabricate deformation-insensitive, high-performance mmWave electronic textiles (E-textiles) by combining specially engineered liquid metal (LM) inks with a high-resolution "dual-mask" printing technique. The LM inks, composed of polyvinylpyrrolidone (PVP)-stabilized gallium-based nanodroplets, exhibit excellent surface compatibility, self-healing behavior, and high conductivity (∼11.16 mΩ/sq), enabling the formation of conformal, durable circuits on textiles. We demonstrate a 26 GHz LM-textile antenna array maintaining 9.65 dBi gain after repeated bending, as well as a microstrip transmission line with a negligible attenuation increase after mechanical cycling. Compared to printed silver inks and metallic-cloth-based antennas, the LM-textile antenna exhibits superior mechanical reliability and maintains a wireless transmission range of 4.5 meters for high-definition images. These results establish LM-textiles as a promising platform for future wearable mmWave devices, offering scalable, flexible, and resilient solutions for high-frequency wireless communication.