Large‐Area Conductor‐Loaded PDMS Flexible Composites for Wireless and Chipless Electromagnetic Multiplexed Temperature Sensors

Abstract Capacitive dielectric temperature sensors based on polydimethylsiloxane (PDMS) loaded with 10 vol% of inexpensive, commercially‐available conductive fillers including copper, graphite, and milled carbon fiber (PDMS‐CF) powders are reported. The sensors are tested in the range of 20–110 °C a...

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Bibliographic Details
Main Authors: Benjamin King, Nikolas Bruce, Mahmoud Wagih
Format: Article
Language:English
Published: Wiley 2025-05-01
Series:Advanced Science
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Online Access:https://doi.org/10.1002/advs.202412066
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Summary:Abstract Capacitive dielectric temperature sensors based on polydimethylsiloxane (PDMS) loaded with 10 vol% of inexpensive, commercially‐available conductive fillers including copper, graphite, and milled carbon fiber (PDMS‐CF) powders are reported. The sensors are tested in the range of 20–110 °C and from 0.5 to 200 MHz, with enhanced sensitivity from 20 to 60 °C, and a relative response of 85.5% at 200 MHz for PDMS‐CF capacitors. PDMS‐CF capacitors are interrogated as a sensing element in wirelessly coupled chipless resonant coils tuned to 6.78 MHz with a response in the resonant frequency (fr) of the sensor, demonstrating an average sensitivity of 0.38% °C−1, a 40x improvement over a pristine PDMS capacitive sensor and outperforms state‐of‐the‐art frequency‐domain radio frequency temperature sensors. Exploiting its high sensitivity, the wireless sensing platform is interrogated using a low‐cost, portable, and open‐source NanoVNA demonstrating a relative response in fr of 48.5%, good agreement with instrumentation‐grade vector network analyzers (VNAs) and negligible change in performance at a range of reading distances and humidities. Finally, a wireless tag is demonstrated with rapid, reversible dynamic response to changes in temperature, as well as the in the first scalable, multiplexed array of chipless sensors for spatial temperature detection.
ISSN:2198-3844