title: Rapid prototyping of microstructures in polydimethylsiloxane (PDMS) by direct UV-lithography.
abstract: Microstructuring of polydimethylsiloxane (PDMS) is a key step for many lab-on-a-chip (LOC) applications. In general, the structure is generated by casting the liquid prepolymer against a master. The production of the master in turn calls for special equipment and know how. Furthermore, a given master only allows the reproduction of the defined structure. We report on a simple, cheap and practical method to produce microstructures in already cured PDMS by direct UV-lithography followed by chemical development. Due to the available options during the lithographic process like multiple exposures, the method offers a high design flexibility granting easy access to complex and stepped structures. Furthermore, no master is needed and the use of pre-cured PDMS allows processing at ambient (light) conditions. Features down to approximately 5 µm and a depth of 10 µm can be realised. As a proof of principle, we demonstrate the feasibility of the process by applying the structures to various established soft lithography techniques.
authors.affiliation: Institute for Biological Interfaces, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany. tim.scharnweber@kit.edu
authors.forename: Tim
authors.initials: T
authors.lastname: Scharnweber
authors.forename: Roman
authors.initials: R
authors.lastname: Truckenmüller
authors.forename: Andrea M
authors.initials: AM
authors.lastname: Schneider
authors.forename: Alexander
authors.initials: A
authors.lastname: Welle
authors.forename: Martina
authors.initials: M
authors.lastname: Reinhardt
authors.forename: Stefan
authors.initials: S
authors.lastname: Giselbrecht
mesh_terms: D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D055616:Microtechnology / Q000379:methods*; D010782:Photolysis; D011327:Printing / Q000379:methods*; D013997:Time Factors; D014466:Ultraviolet Rays
chemical_list: D004129:Dimethylpolysiloxanes; C013830:baysilon