Maskless visible-light photolithography of copper microheater for dynamic microbioreactor

Abstract

Advances in microfabrication have led to the development of microbioreactor including microheater as one of important components for microbioreactor. Microheater should be fabricated based on specific requirement of microbioreactor including shape, size, target working temperature, and heating rate profile, where they would determine the heat distribution to the microbioreactor. Here, we propose serpentine-shaped and spiral-shaped microheaters for a dynamic-flow microbioreactor. Computer models were generated and characterized by finite element analysis (FEA) to simulate the heating performance. Microheaters were then fabricated by maskless photolithography using visible light generated by a commercial digital light projector (DLP) followed by wet etching. Geometrical features of fabricated microheaters were then measured to characterize the design transfer. FEA result shows that given same amount of input electrical power and observation time; both microheaters have different heat distribution profiles which could affect the heating control scheme. Geometrical measurement on certain segments shows that the current fabrication technique can transfer the design with dimensional error percentage of 0.5 to 39 % without significant change in the geometrical shape.Advances in microfabrication have led to the development of microbioreactor including microheater as one of important components for microbioreactor. Microheater should be fabricated based on specific requirement of microbioreactor including shape, size, target working temperature, and heating rate profile, where they would determine the heat distribution to the microbioreactor. Here, we propose serpentine-shaped and spiral-shaped microheaters for a dynamic-flow microbioreactor. Computer models were generated and characterized by finite element analysis (FEA) to simulate the heating performance. Microheaters were then fabricated by maskless photolithography using visible light generated by a commercial digital light projector (DLP) followed by wet etching. Geometrical features of fabricated microheaters were then measured to characterize the design transfer. FEA result shows that given same amount of input electrical power and observation time; both microheaters have different heat distribution profiles w...