Lin Pin-Tso, Chu Heng-Yi, Lu Tsan-Wen, Lee Po-Tsung
Department of Photonics, National Chiao Tung University, Room 413 CPT Building, 1001 Ta-Hsueh Road, Hsinchu 300, Taiwan.
Lab Chip. 2014 Dec 21;14(24):4647-52. doi: 10.1039/c4lc00731j. Epub 2014 Oct 7.
We propose and demonstrate a trapping configuration integrating coupled waveguides and gold bowtie structures to form near-field plasmonic tweezers. Compared with excitation from the top, waves coupled through the waveguide can excite specific bowties on the waveguide and trap particles precisely. Thus this scheme is more efficient and compact, and will assist the circuit design on a chip. With lightning rod and gap effects, the gold bowtie structures can generate highly concentrated resonant fields and induce trapping forces as strong as 652 pN W(-1) on particles with diameters as small as 20 nm. This trapping capability is investigated numerically and verified experimentally with observations of the transport, trapping, and release of particles in the system.
我们提出并展示了一种集成耦合波导和金蝴蝶结结构以形成近场等离子体镊子的捕获配置。与从顶部激发相比，通过波导耦合的波可以激发波导上的特定蝴蝶结并精确捕获粒子。因此，该方案更高效、更紧凑，并将有助于芯片上的电路设计。借助避雷针效应和间隙效应，金蝴蝶结结构可以产生高度集中的共振场，并在直径小至20nm的粒子上诱导出高达652 pN W(-1)的捕获力。通过对系统中粒子的传输、捕获和释放进行观测，对这种捕获能力进行了数值研究和实验验证。
