Zaman Mohammad Asif, Wu Mo, Ren Wei, Jensen Michael A, Davis Ronald W, Hesselink Lambertus
Department of Electrical Engineering, Stanford University, Stanford, California 94305, USA.
Department of Biochemistry, Stanford University, Stanford, California 94305, USA.
Appl Phys Lett. 2023 Jul 24;123(4):041104. doi: 10.1063/5.0160939. Epub 2023 Jul 25.
An optoelectronic tweezer (OET) device is presented that exhibits improved trapping resolution for a given optical spot size. The scheme utilizes a pair of patterned physical electrodes to produce an asymmetric electric field gradient. This, in turn, generates an azimuthal force component in addition to the conventional radial gradient force. Stable force equilibrium is achieved along a pair of antipodal points around the optical beam. Unlike conventional OETs where trapping can occur at any point around the beam perimeter, the proposed scheme improves the resolution by limiting trapping to two points. The working principle is analyzed by performing numerical analysis of the electromagnetic fields and corresponding forces. Experimental results are presented that show the trapping and manipulation of micro-particles using the proposed device.
本文介绍了一种光电子镊子（OET）装置，在给定光斑尺寸下，该装置具有更高的捕获分辨率。该方案利用一对图案化的物理电极产生不对称电场梯度。这反过来除了产生传统的径向梯度力之外，还会产生一个方位力分量。沿着光束周围的一对对映点实现稳定的力平衡。与传统的光电子镊子不同，传统光电子镊子在光束周边的任何点都可能发生捕获，而该方案通过将捕获限制在两个点来提高分辨率。通过对电磁场和相应力进行数值分析来分析其工作原理。给出了实验结果，展示了使用该装置对微粒的捕获和操控。
