Photopatterning of a p(HEMA) based, pH-sensitive hydrogel

Conference · Fri Dec 31 04:00:00 EST 1993

OSTI ID:141790

Lesho, M J; Sheppard, Jr, N F ^[1]

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1. John Hopkins Univ., Baltimore, MA (United States)

A photopolymerization process was used to prepare patterned films of poly(hydroxyethyl methacrylate -co- dimethylaminoethyl methacrylate) hydrogels with lateral dimensions of a few mm. Lithographic sensitivity, thickness, lateral resolution, and adhesion were characterized. To prepare the films, a prepolymer solution as formulated consisting of the monomers, crosslinker, photoinitiator and poly(HEMA) to increase viscosity. This was spun at various spin speeds onto oxidized silicon wafers treated with a silane adhesion promoter. The wafers were then exposed through a photomask to UV light to effect the polymerization. At a photoinitiator concentration of 2% w/w and an ultraviolet dose greater than 400 mJ/cm{sup 2}, gels were reproducible and ranged in thickness from 3.5 to 22 microns depending on the p(HEMA) concentration and spin speed. Edge effects at the mask boundary limited the lateral resolution to 60 microns. Films remained adherent up to 4 weeks while undergoing daily cycling from pH 5 to 9.

• OSTI ID: 141790
• Report Number(s): CONF-930304--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
FILMS
GELS
METHACRYLATES
PH VALUE
PHOTOCHEMICAL REACTIONS
POLYMERIZATION
SURFACE FINISHING