Electric split-ring metamaterial based microfluidic chip with multi-resonances for microparticle trapping and chemical sensing applications

Electric split-ring metamaterial based microfluidic chip for label-free microparticles trapping and biosensing applications. (TS: trapping structure). [Display omitted] •An integration of terahertz (THz) electrical split-ring metamaterial (eSRM) with microfluidic chip is presented.•A label-free strategy in microparticle trapping and detecting is proposed for biosensing application.•eSRM-based microfluidic chip exhibits multiple resonances and selectively microparticle trapping characteristic.•eSRM-based microfluidic exhibits high sensitivity to detect microparticles in TE mode. In this work, an integration of terahertz (THz) electrical split-ring metamaterial (eSRM) with microfluidic chip is presented. This eSRM-based microfluidic chip exhibits multiple resonances in the THz spectrum and trapping selectively microparticle size characteristics. The arrangement of eSRM array is dislocation. It generates the fundamental inductive-capacitive (LC) resonant mode, quadrupole, and octupolar plasmon resonant modes and then exhibits high sensitivity to the environmental refraction index. The trapping structures of microparticles are elliptical barricades on eSRM surface. Thus, the electric field energy is strongly confined within the gap of eSRM in transverse electric (TE) mode and then the elliptical trapping structures are anchored on both sides of the split gap to ensure the microparticles can be trapped and located on the gap. To imitate the microparticle sensing ambient environment qualitatively and quantitatively in the THz spectrum, the microparticles are designed different feature sizes with different refraction index from 1.0 to 2.0 in ethanol medium. The results show the proposed eSRM-based microfluidic chip possesses the trapping and sensing abilities in single microparticle and high sensitivity for fungus, microorganism, chemical and environmental applications.