Lei Hongxiang, Zhang Yao, Li Baojun
State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou, China.
Opt Express. 2012 Jan 16;20(2):1292-300. doi: 10.1364/OE.20.001292.
We report a separation of two different size particles in fluidic flow by an optical fiber. With a light of 1.55 μm launched into the fiber, particles in stationary water were massively trapped and assembled around the fiber by a negative photophoretic force. By introducing a fluidic flow, the assembled particles were separated into two different downstream positions according to their sizes by the negative photophoretic force and the dragging force acted on the particles. The intensity distribution of light leaked from the fiber and the asymmetry factor of energy distribution have been analysed as crucial factors in this separation. Poly(methyl methacrylate) particles (5-/10-μm diameter), SiO(2) particles (2.08-/5.65-μm diameter), and SiO(2) particles (2.08-μm diameter) mixed with yeast cells were used to demonstrate the effectiveness of the separation. The separation mechanism has also been numerical simulated and theoretical interpreted.
我们报道了一种利用光纤在流体流动中分离两种不同尺寸颗粒的方法。将波长为1.55μm的光注入光纤，静止水中的颗粒会因负光泳力而大量捕获并聚集在光纤周围。通过引入流体流动，聚集的颗粒会根据其尺寸，在负光泳力和作用于颗粒的拖曳力的作用下，被分离到两个不同的下游位置。已分析了从光纤泄漏的光的强度分布和能量分布的不对称因子，作为这种分离中的关键因素。使用聚甲基丙烯酸甲酯颗粒（直径5/10μm）、二氧化硅颗粒（直径2.08/5.65μm）以及与酵母细胞混合的二氧化硅颗粒（直径2.08μm）来证明分离的有效性。还对分离机制进行了数值模拟和理论解释。
