Metamaterial-based sensor design using split ring resonator and Hilbert fractal for biomedical application

In this work, a novel approach is presented to design a metamaterial-based sensitive sensor for biomedical applications. The metamaterial-based sensor objective is to differentiate between different types of cancer cell lines (biological cells) based on their electrical properties. The sensor is designed by incorporating a single circular split ring resonator (SRR) and a Hilbert fractal curve. The SRR is designed based on its capacitive and inductive resonance properties, thereby making the SRR a favorable candidate for sensing applications. Moreover, the Hilbert fractal curve is introduced as a defected ground structure to move the resonance frequency of the SSR to lower band, and to increase sensor sensitivity. Different Hilbert curve orders are investigated. The fourth-order Hilbert curve is used in the final design as it showed the optimal performance among other orders. To verify the sensor functionality and selectivity, the proposed sensor is tested on three types of breast cancer cell lines, these are MCF7, MCF-7, and HS578T. Measurement results of the fabricated sensor compared well with simulated results obtained using high-frequency structure simulator (HFSS18).