Energy-efficient and Secure Wireless Body Sensor Networks with Metamaterial Textiles

Wearable sensors can be connected to form a wireless body sensor network (WBSN) for applications in physiological monitoring and continuous healthcare. However, wireless connection between devices is currently achieved by radiating signals into the space around the body, which is in general energy-inefficient and vulnerable to eavesdropping attacks. We have recently demonstrated that clothing structured with conductive textiles - termed metamaterial textiles - can support surface-plasmon-like modes that enable wireless signals emitted by standard devices to efficiently and securely propagate around the body. Here, we show that the metamaterial textiles enable wireless signals to be localized to a distance of 10 cm while maintaining connectivity around the body, and demonstrate efficient (~10%) wireless power transfer using antennas optimized for interaction with surface plasmon modes. These results demonstrate that clothing integrated with metamaterial textiles could facilitate wireless powering of battery-free sensors around the body to sense and respond to physiological signals.