A microfluidic sensor based on meta-surface absorber for rapid and nondestructive identification of edible oil species

Abstract

—In this paper, a sensor based on a meta-surface absorber loaded with microfluidics is proposed for identification of edible oil species and provides a non-destructive, rapid, and convenient technology for the measured samples. First, a narrow-band absorber with absorption frequency of 9.887 GHz and Q value of 147, which is implemented with four W-shaped meander line resonators, is designed by Finite Element Method. Its corresponding electromagnetic resonance mechanism is explored to reveal absorption characteristics, build its corresponding equivalent circuit model, and guide the design of the palindromic microfluidic channel. The sensor shows a high sensitivity of 500 MHz/ε′r,and the corresponding sensing performance is experimentally validated by the fact that the distinguishable resonance absorption frequency shift is 461 MHz, 458 MHz, 449 MHz, 444 MHz, and 436 MHz when rapeseed oil, corn oil, peanut oil, sesame oil, and olive oil are loaded into the microfluidic channel, respectively. The identification is successfully achieved according to the resonance absorption frequency shift. Moreover, a good agreement between the simulated and measured results demonstrates that the proposed meta-surface-inspired sensor is a promising candidate to monitor and determine the quality of edible oil to some extent, and is relatively valuable to the modern agriculture and food industry.