Optoelectronic Heating for Fabricating Microfluidic Circuitry

Abstract

This work reports on optoelectronic-based heaters that can transduce low-power optical images into high-power heating to melt frozen liquids and form desired microfluidic circuitry. The mechanism of optoelectronic heating (OEH) was studied and characterized. OEH relies on photocurrent heating in the illuminated parts of actuating images. Resolution was affected by dark current heating. Photocurrents and dark currents were measured and related to the operating parameters. Successful melting of a frozen media within seconds with 2 mW light patterns and a 4 V operating voltage was demonstrated with feature sizes down to 200 μm × 200 μm. Strategies to increase resolution were addressed. It was shown that the size and location of heating areas can be reliably and rapidly reconfigured by changing the actuating image.