Body-resonance: transmission line-like wireless links enabling high-speed wearable communication.

Seamless interaction between humans and Artificial Intelligence-empowered, battery-operated, miniaturized devices is reshaping wearable technology by forming an anthropomorphic artificial nervous system that demands high-speed, low-power connectivity. Besides being radiative, radio frequency links suffer absorption losses in non-line-of-sight scenarios and consume more than tens of milliwatts of power. Electro-quasistatic human body communication provides non-radiative links with  ~100X better energy efficiency and  ~30X superior signal confinement over radio wave-based wireless. However, it is limited by  ~60-70 dB path loss, limited bandwidth, and data rates ≤30 Mbps, insufficient for applications such as High definition streaming, and distributed computing at wearable sensor nodes. To overcome these challenges, we propose Body-Resonance Human Body Communication, which leverages the human body's transmission-line behavior in the near-intermediate field to enhance channel capacity by up to 30X. It achieves approximately 20 dB higher channel gain and a wider bandwidth compared to electro-quasistatic regime, supporting data rates of hundreds of Mbps. Experimental results validate low-loss (~40-50 dB), wideband body channels that are more than 10X less leaky than antenna-based wireless links. Body Resonance can potentially open up the possibilities of immersive augmented/virtual reality and cooperative on-body computing by enabling energy-efficient, high-speed wearable networks across healthcare, defense, and consumer electronics.