title: Photomodification of polymer microchannels induced by static and dynamic excimer ablation: effect on the electroosmotic flow.
abstract: This paper presents a study of polymer surfaces modified by laser ablation using poly(ethylene terephthalate) (PET) as a model system. The surface properties induced by static and dynamic ablation with the 193-nm pulsed radiation of an ArF excimer laser (4 x 10(7) W/cm2) in air have been successfully used to control the electroosmotic flow (EOF) in photoablated PET microchannels. Through the creation of well-defined static ablation patterns onto the walls of a trapezoidal channel, it was found that the resulting reduction in the EOF could be controlled. For example, a reduction of 25% in the EOF was observed in 42-microm-deep microchannels when using a static ablation pattern treating 50% of the total wall surface area. A numerical study describing the fluidic behavior induced by a static pattern is also presented. Moreover, X-ray photoelectron spectroscopy has been used to point out surface changes between static and dynamic ablation, thereby demonstrating an ability to create new functionalities in microchannels by laser treatment.
authors.affiliation: Laboratoire d'Electrochimie, Ecole Polytechnique Fédérale de Lausanne, Switzerland.
authors.forename: F
authors.initials: F
authors.lastname: Bianchi
authors.forename: Y
authors.initials: Y
authors.lastname: Chevolot
authors.forename: H J
authors.initials: HJ
authors.lastname: Mathieu
authors.forename: H H
authors.initials: HH
authors.lastname: Girault