Development of low-fluorescence thick photoresist for high-aspect-ratio microstructure in bio-application

H Tamai; K Maruo; H Ueno; K Terao; H Kotera; T Suzuki

doi:10.1063/1.4917511

Development of low-fluorescence thick photoresist for high-aspect-ratio microstructure in bio-application

Biomicrofluidics. 2015 Apr 13;9(2):022405. doi: 10.1063/1.4917511. eCollection 2015 Mar.

Authors

H Tamai¹, K Maruo², H Ueno¹, K Terao¹, H Kotera³, T Suzuki¹

Affiliations

¹ Department of Intelligent Mechanical Systems Engineering, Kagawa University , 2217-20 Hayashi-cho, Takamatsu, Kagawa 761-0396, Japan.
² Central Research Center, Daicel Corporation , 1239 Shinzaike, Aboshi-ku, Himeji, Hyogo 671-1283, Japan.
³ Department of Microengineering, Kyoto University , Kyoto daigaku Katsura, Nishikyo-ku Kyoto 615-8540, Japan.

Abstract

In this study, we propose and evaluate a novel low-auto-fluorescence photoresist (SJI photoresist) for bio-application, e.g., in gene analysis and cell assay. The spin-coated SJI photoresist has a wide thickness range of ten to several hundred micrometers, and photoresist microstructures with an aspect ratio of over 7 and micropatterns of less than 2 μm are successfully fabricated. The emission spectrum intensity of the SJI photoresist is found to be over 80% less than that of the widely used SU-8 photoresist. To evaluate the validity of using the proposed photoresist in bio-application for fluorescence observation, we demonstrate a chromosome extension device composed of the SJI photoresist. The normalized contrast ratio of the SJI photoresist exhibits a 50% improvement over that of the SU-8 photoresist; thus, the SJI photoresist is a versatile tool for bio-application.