The flow of a fluid around an optically trapped particle forces the particle to move out of its equilibrium position. The particle will escape the trap if the fluid velocity exceeds a certain limit. Accordingly, we propose a novel and accurate method to sort the particles due to a difference in their escape velocities that depends on the size and refractive index of the particles. Here, the influence of the numerical aperture of the microscope objective and laser power on the escape velocities are studied for calibration. In addition, the method is used to sort various pairs of the particles; polystyrene beads with diameters of 1.48 and 2.18 micron, 1.65 and 3.0 micron, and 3.0 micron silica and polystyrene beads. The results show an efficiency of about 95% to locate the particles into the desired region. To verify the capability of the method for cell sorting, we have accomplished this technique to sort thalassemia red blood cells from healthy ones. Our presented method, as an ...

中文翻译：

---

使用自制压电镜在光镊系统中进行逃逸速度分选

围绕被光学捕获的粒子的流体流动迫使粒子移出其平衡位置。如果流体速度超过一定极限，粒子将逃脱陷阱。因此，我们提出了一种新颖且准确的方法来对颗粒进行分选，这归因于取决于颗粒尺寸和折射率的颗粒逃逸速度的差异。在这里，研究了显微镜物镜的数值孔径和激光功率对逃逸速度的影响，以进行校准。另外，该方法用于分类各种不同的颗粒。直径为1.48和2.18微米，1.65和3.0微米的聚苯乙烯珠以及3.0微米的二氧化硅和聚苯乙烯珠。结果表明，将颗粒定位到所需区域的效率约为95％。为了验证细胞分选方法的功能，我们已经完成了这项技术，可以将健康的地中海贫血红细胞分选出来。我们提出的方法，作为...