A Wireless, Zero-Power and Multiplexed Sensor for Wound Monitoring

In this work, a battery-free wireless multiplexed sensor is presented for monitoring the wound healing process. The compact, integrated wireless wound sensor can simultaneously detect moisture and temperature at the wound or surgical site with high sensitivity and accuracy. Specifically, design of the sensor telemetry system is inspired by the concept of higher-order parity-time (PT)-symmetry in quantum mechanics, but implemented in a circuit analogy, of which the spatially balanced and distributed gain, neutral and loss elements are represented by active -RLC reader, LC intermediator and RLC sensor. By leveraging the constant and branching eigenvalues in the complex-frequency plane, impedance perturbations in multiple sensors can be deterministically read. Our experimental results show that the multimodal wireless wound sensor exhibits high sensitivity and robustness in instantaneously detecting temperature (25–50 °C) and relative humidity (30%-90%). With further development, the proposed sensor may detect multiple wound healing indictors including temperature, humidity, pH value, strain, and uric acid level.