Surface modification of 2D/3D SU-8 patterns with a swelling–deswelling method

Abstract

The grafting of PEG onto 2D and 3D SU-8 patterns with a swelling–deswelling approach has been demonstrated. The grafting density can be controlled by varying the amount of solvent used in the swelling. The grafting of the PEG-PPG-PEG block copolymers was confirmed directly with fluorescence characterization, and the control of the grafting density was assessed by performing contact-angle measurements. We also achieved the introduction of DNA molecules onto SU-8 patterns with the same approach. The swelling–deswelling approach is an inert and facile surface modification method, and can be extended to various SU-8 patterns for lab-on-a-chip applications and MEMS.