Fabrication of high-transmission microporous membranes by proton beam writing-based molding technique

NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION B-BEAM INTERACTIONS WITH MATERIALS AND ATOMS

卷:404

Article; Proceedings Paper

Wang, Liping¹  Meyer, Clemens^1,2  Guibert, Edouard¹  Homsy, Alexandra¹  Whitlow, Harry J.^1,3 

[1] Univ Appl Sci Western Switzerland HES SO, Haute Ecole Arc Ingn, Eplatures Grise 17, CH-2300 La Chaux De Fonds, Switzerland

[2] Univ Augsburg, Inst Phys, D-86135 Augsburg, Germany

[3] Univ Louisiana Lafayette, Dept Phys, Louisiana Accelerator Ctr, Lafayette, LA 70503 USA

关键词: Proton beam writing;    Microfabrication;    Porous membranes;    Release coating;    Soft lithography;   

DOI  :  10.1016/j.nimb.2017.04.069

来源: Elsevier

【 摘 要 】

Porous membranes are widely used as filters in a broad range of micro and nanofluidic applications, e.g. organelle sorters, permeable cell growth substrates, and plasma filtration. Conventional silicon fabrication approaches are not suitable for microporous membranes due to the low mechanical stability of thin film substrates. Other techniques like ion track etching are limited to the production of randomly distributed and randomly orientated pores with non-uniform pore sizes. In this project, we developed a procedure for fabricating high-transmission microporous membranes by proton beam writing (PBW) with a combination of spin-casting and soft lithography. In this approach, focused 2 MeV protons were used to lithographically write patterns consisting of hexagonal arrays of high-density pillars of few mu m size in a SU-8 layer coated on a silicon wafer. After development, the pillars were conformably coated with a thin film of poly-para-xylylene (Parylene)-C release agent and spin coated with polydimethylsiloxane (PDMS). To facilitate demolding, a special technique based on the use of a laser-cut sealing tape ring was developed. This method facilitated the successful delamination of 20-mu m thick PDMS membrane with high-density micropores from the mold without rupture or damage. (C) 2017 Elsevier B.V. All rights reserved.

【 授权许可】

Free