Nanorefrigerative tweezers for optofluidic manipulation

Abstract

Plasmonic optical tweezers with the ability to manipulate nano-sized particles or molecules that are beyond the diffraction limit have been developed rapidly in recent years. However, plasmonic heat generation always limits its applications in capturing particles or biomacromolecules that are vulnerable to high temperatures. Here, we propose nanorefrigerative tweezers based on a single refrigerative nanocrystal, which can form a nanometer-sized cold-spot via anti-Stokes fluorescence. Numerical simulations are performed to compute the temperature and velocity fields. The results show that thermo-osmosis and thermophoresis play major roles in nanoparticle manipulation, while natural convection in the nanoscale is negligible. This tweezing scheme not only offers a sub-diffraction-limit way to manipulate nano-objects but also avoids possible thermal damage to the trapped targets. Therefore, it will potentially become a powerful tool in biomedical and biosensing research studies.

Highly‐Adaptable Optothermal Nanotweezers for Trapping, Sorting, and Assembling across Diverse Nanoparticles

“…Note that natural convective flow is suppressed due to the shallower chamber height (30 μm). [66,67]…”

光致温度场光镊：原理及生物医学应用

“…钟义立， 彭宇航， 陈嘉杰 * ， 周健行， 戴小祺， 张晗， 屈军乐， 邵永红 深圳大学物理与光电工程学院，射频异质异构集成全国重点研究实验室，光电子器件与系统教育部/广东省重点实验 室，广东 深圳 518060 2 Schematic of refrigerative tweezers for nanoparticles manipulation [42] 图 3 温度场粒子驱动的物理机制 ［32］ 。 (a)热泳示意图； (b)热电效应示意图 Fig. 3 Physical mechanisms of OTFT [32] .…”