Rounding of Negative Dry Film Resist by Diffusive Backside Exposure Creating Rounded Channels for Pneumatic Membrane Valves

Micromachines

Philipp Frank²  Sebastian Haefner²  Georgi Paschew²  Andreas Richter¹ 

[1] Polymeric Microsystems, Institute of Semiconductors and Microsystems, Technische Universität Dresden, 01062 Dresden, Germany

关键词: soft lithography;    dry film resist;    microfluidics;   

DOI  :  10.3390/mi6111442

来源: mdpi

【 摘 要 】

Processing of dry film resist is an easy, low-cost, and fast way to fabricate microfluidic structures. Currently, common processes are limited to creating solely rectangular channels. However, it has shown that rounded channels are necessary to ensure proper closing of pneumatic membrane valves for microfluidic devices. Here, we introduce a modification to the standard lithography process, in order to create rounded channels for microfluidic structures. Therefore, a diffuser element was inserted into in the optical path between the light source and glass substrate, which is then exposed through the backside, hence altering the exposure to the dry resist spatially. Characterization of the process was carried out with different exposure times, features sizes, and substrate thickness. The process modification is almost effortless and can be integrated in any lithography process.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.