Optical fiber-based manipulation of microparticles in microfluidic channel through thermal convection

We demonstrate a simple optical fiber microfluidic control device based on photothermal effect induced convection, which can realize flexible manipulation and particle sorting over a range of hundreds of microns. Three single-mode optical fibers in a regular arrangement were utilized for the realization of the particle capture function, which simplifies the complex equipment and reduces the cost in traditional optical tweezers. We also display a unique control mode: the horizontal manipulation of particles by moving the fiber vertically. It will hopefully be applied in biomedical, chemical analysis, material testing and other fields.