A catalytically powered electrokinetic lens: toward channelless microfluidics

摘要

A chemically powered channelless microfluidic device was designed, fabricated, and characterized. The device consists of an asymmetric silver-gold bimetallic catalytic junction fabricated on a silicon dioxide surface. The decomposition of hydrogen peroxide at the silver-gold interface generates a proton gradient and an associated electric field which in turn drives electroosmosis and electrophoresis when a charged particle is present in the vicinity of the field. By engineering an asymmetric device consisting of an isolated junction, continuous electroos-motic fluid flow across the device has been achieved. In addition, a new device geometry has been developed which is capable of focusing and directing negatively charged particles along a desired path without the need of micro-channels. The efficiency and ease of the fabrication suggest the possibility of many versatile applications including biological molecule sorting and manipulation.