Integration of Wireless Power Transfer Technology With Hierarchical Multiwalled Carbon Nanotubes-Polydimethylsiloxane Piezo-Responsive Pressure Sensor for Remote Force Measurement

Integrating sensory devices with wireless power transfer technology for remote sensing (RS) requires the implementation of complex electronic circuitry and communication protocols. To overcome this challenge and remotely monitor mechanical force, we directly integrated piezo-responsive porous multiwalled carbon nanotubes (MWCNTs)/polydimethylsiloxane (PDMS) nanocomposites with a near-field wireless power transfer system. The wireless system transfers power bidirectionally between the transmitter and the sensing receiver at the resonant frequency of 13.56 MHz. The detection principle is based on the mechanical force-induced impedance changes in the receiver circuit. The modulated impedance signal is detected wirelessly at the transmitter circuit via a full-bridge rectifier and a smoothing capacitor. Furthermore, we demonstrate the wireless monitoring of finger bending and applied force using our flexible and disposable sensor without using any energy storage devices. The results suggest a response and recovery time of 400 ± 50 ms, strain sensitivity of 24.73, and pressure sensitivity of 0.98. Our approach adds a new path for disposable haptic-based sensory applications that do not require complex communication protocols in medical, robotics, and other fields.