Kirigami Inspired Inkjet-Printed Split Ring Resonator as a Disposable, Low Cost Strain Sensor

초록

The study presents a kirigami inspired split ring resonator (SRR) strain sensor. Since the SRR resonance frequency depends strongly on its split gap, one kirigami cut was designed to align with the SRR split gap, allowing SRR resonance frequency to be varied by applying uniaxial stress. The strain sensing mechanism is explained based upon the relationship between frequency and induced strain. A composite substrate comprised of two paper sheets bonded using epoxy is used as the dielectric. An SRR coupled with microstripline is inkjet-printed on the top paper using silver nanoparticle ink, and the ground plane on the bottom paper is realized using stretchable ink. Reflection coefficients for the fabricated prototype are measured at different strain levels. Resonance frequency increases from 4 to 4.64 GHz for 17.24% applied strain, with measured strain sensitivity = 4.2\times 10^{7}\ \text{Hz}/\%, and minimum detectable strain level ≈ 0.84%. The proposed strain sensor is easy to manufacture, low cost, and disposable because it is inkjet-printed on paper. Thus, paper-based strain sensor can be considered a suitable substitute of polymer-based strain sensor. © 2020 IEEE.

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