Experimental Study of Adulteration Detection in Fish Oil Using Novel PDMS Cavity Bonded EBG Inspired Patch Sensor

Abstract

In this paper, a high impedance surface electromagnetic bandgap inspired resonator patch, bonded with a polydimethylsiloxane (PDMS) cavity was implemented as a sensor device for detecting adulteration in a fish oil dietary supplement. The fabricated sensor on a Neltec substrate of relative permittivity ( $\varepsilon _{r}= 3.2$ ) and dissipation factor (tan $\delta = 0.007$ ) has a unique pattern of electromagnetic bandgap unit cells, and offers TM01, TM11, and TM21 transverse magnetic modes for dielectric spectroscopy of the sample. The measured reflection coefficient at 2.592 GHz of the air-filled PDMS cavity bonded to the patch sensor under TM01 mode was used for calibrating the sensor subjected to 10%, 20%, 30%, 40%, and 50% adulteration in the fish oil. With olive oil as an adulteration ingredient inside fish oil, a maximum shift of 70 MHz was observed in the sensor frequency response for 50% adulteration level. A linearity of more than 91% was achieved in the response of the developed sensor.