An Opto-Electric Micropump for Saline Fluids

TL;DR

This paper introduces an opto-electric micropump that uses focused laser heating and electric fields to control saline fluid flow in lab-on-chip devices, allowing adjustable direction and flow rate.

Contribution

It presents a novel laser-based heating method combined with electric fields for precise fluid pumping in microfluidic systems.

Findings

Flow velocities up to tens of micrometers per second achieved.

Flow direction and rate can be easily controlled by changing the focal area.

Applicable to NaCl+water solutions in lab-on-chip devices.

Abstract

A novel method to pump fluid in lab on chip devices with velocities up to tens of micrometer per second is introduced. A focused laser beam locally heats up an electrolyte. A net charge tends to accumulate in the heat-absorbing area, due to unequal tendencies of positive and negative ions to move in the presence of the temperature gradient. An external electric field then exerts a net force on the accumulated charge and consequently on water. This causes flow of water, with velocities up to tens of micrometer per second, for a simple NaCl+water solution. The method lets us change direction and amount of fluid pumping, simply by replacing the focal area.