NFC based Polymer Strain Sensor for Smart Packaging

This paper presents a polymer strain sensor integrated with an NFC tag to detect strain semi-quantitatively. The strain sensor is fabricated using flexible and transparent polymer Polydimethylsiloxane (PDMS) microchannel having conductive polymer poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as an active material. The sensor was tested with different bending conditions and it was found that the resistance increases with higher bending. A maximum of 3 order change in resistance was observed for $\sim$100□ bending. The sensor was finally tested using a custom-developed passive NFC tag having an LED connected in series with the strain sensor and powered from the reader via the NFC antenna in the tag.