Microparticle collection for water purification based on laser-induced convection

摘要

Water purification is required for environmental protection.In this paper,we propose and demonstrate a rapid,effective and low-cost approach to collect numerous impurities (microparticles) in water on the basis of laser-induced thermal convection.We introduce a heat source by using a fiber tip,which is fabricated into a non-adiabatic-tapered shape.In order to improve the laser power absorption efficiency,we coat a gold film with a thickness of 300 nm on the fiber tip.Due to absorption,the laser power transferred from the fiber to the water results in thermal convection.The forces generated from the thermal convection drive the microparticles to move towards the fiber tip,thereby performing microparticle collection and achieving water purification.Laser-induced thermal convection provides a simple,high-efficiency and low-cost method of collecting microparticles,which is a suitable and convenient for local water purification.