Microfluidic Eighth-Mode Substrate-Integrated-Waveguide Antenna for Compact Ethanol Chemical Sensor Application

Abstract

In this communication, a microfluidic antenna is proposed for chemical sensor applications. An eighth-mode substrate-integrated-waveguide (EMSIW) antenna with a microfluidic channel is introduced in order to devise a compact and nondestructive chemical sensor. The frequency response of the proposed antenna is controlled by changing the nanoliter liquid in the microfluidic channel, which further results in a change in the effective dielectric constant. First, the EMSIW antenna is designed, and then the microfluidic channel is designed for nondestructive chemical sensor applications. The S-parameters of the proposed microfluidic EMSIW antenna are simulated and measured. The resonant frequency is successfully switched from 4.2 to 4.6 GHz when the concentration of ethanol is changed from 0% to 100%. The possibility of the proposed antenna to be used as an ethanol chemical sensor is demonstrated from the relationship between the resonant frequency and the concentration of ethanol.