Sheathless particle focusing in a microfluidic chamber by using the thermoplasmonic Marangoni effect

摘要: We experimentally investigated the modes of Marangoni flow around a microbubble in 50-μm-thick water chamber and found transition mode that enables sheathless particle focusing. A temperature gradient was thermoplasmonically induced laser spot on gold nanoisland film, flows were generated to drive submicron particles dispersed water. When slightly displaced from bubble center, continuously collected by underneath leaked one direction form focused stream. The generation particle-focusing attributed appropriate balance perpendicular horizontal directions chamber, which controlled position against center. Temporally controlling this with power caused periodic emission clustered underneath. This handling method thermoplasmonic can be useful for improving efficiency reaction or sensing processes take place microfluidic chamber.