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

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 (ε
_r
= 3.2) and dissipation factor (tanδ = 0.007 ) has a unique pattern of electromagnetic bandgap unit cells, and offers TM
₀₁
, TM
₁₁
, and TM
₂₁
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 TM
₀₁
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.