Battery-free flexible wireless sensors using tuning circuit for high-precision detection of dual-mode dynamic ranges

Abstract

Tracking the dynamic range of properties in objects plays a crucial role in intelligent systems. However, complexity and discrete circuitry continue to pose significant challenges in achieving miniaturized integration and high-precision detection. Inspired by RFID tags, we introduce a flexible passive wireless sensor that detects pressure and temperature parameters of the contact object. The sensor features inductor-capacitor-resistance changes based on concentric fiber-membrane components for precisely decoupling frequency and amplitude shifts by tuning a resonant circuit, which enables a sensing performance for 600 kPa and 67 °C with distinguishing a pressure limit of 1 Pa and a temperature limit of 0.1 °C. The sensor can be paired with a portable vector network analyzer for wireless electrical signal monitoring, thus illustrating the broad utility. This design strategy enables potential applications in smart human-machine interfaces and personal health monitoring.