Smart Surfaces: Reversible Switching of a Polymeric Hydrogel Topography

MOLINA M.A.; RIVAROLA C.R.; BROGLIA, M.F.; ACEVEDO D.F.; BARBERO C.A.

SOFT MATTER

ROYAL SOC CHEMISTRY

Año: 2011 vol. 8 p. 307 - 310

1744-683X

Patterns imprinted on smart surfaces are fabricated by direct laser interference patterning (DLIP) of thick films based on poly(N-isopropylacrylamide) (PNIPAM) doped with suitable dyes. Optical and Atomic Force (AFM) microscopy images reveal that the pattern imprinted on the dry hydrogel film (line-arrays) becomes flat by swelling of the hydrogel upon immersion in water. The pattern re-emerges after drying the hydrogel. Heating the hydrogel above the phase transition temperature of PNIPAM (ca. 32 oC) also restores the pattern by hydrogel volume collapse. This behaviour suggests that this patterning technique allow us to produce surfaces useful for technological application.