Mei Zhu, Jun Chen, Jie Li, Jing Xiao, Jiguo Geng,
http://iopscience.iop.org/article/10.1088/1361-6463/aaf6c1/pdf
To improve the sensitivity of detecting micro-particles, we propose new designs of terahertz metamaterial devices. These devices use microstructures to support the metal layer of metamaterial and thus can trap micro-particles at sensitive positions. We present two methods of selectively trapping micro-particles on such devices. One is to trap the micro-particles at the openings of split-ring-resonators (SRR), and the other is to trap them inside the SRR. Both methods use simple thumb gestures to control the movement of micro-particles. The methods can capture particles over a large surface area with time efficiency and low cost. Single particle trapped at each trapping site was achievable; the trapping rate was 64% using the first method, and 71% using the second. As a result, the resonant frequency before and after the micro-particles were trapped shifted 23 GHz for the first method and 71 GHz for the second. This shows great improvement as compared to earlier report of 15% trapping rate and 10 GHz resonant frequency shift.
