4M Knowledge base - papers

S. Wilson (a),(b), W.Pfleging (c), A. Welle (d), P.Kirby (b), M.Przylbyski (e)

(a) Institute for Microstructure Technology, Forschungszentrum Karlsruhe, 76344 Eggenstein-L, DE
(b) School of Applied Sciences., Cranfield University, Cranfield, Beds. MK43 0AL, UK
(c) Institute for Materials Research 1, Forschungszentrum Karlsruhe, 76344 Eggenstein-L, DE
(d) Institute for Biological Interfaces, Forschungszentrum Karlsruhe, 76344 Eggenstein-L, DE
(e) ATL Lasertechnik GmbH, Burger Str. 48, 42929 Wermelskirchen, Germany

Abstract

Laser patterning is of interest for MST applications; direct ablation of polymer material for generating 2D and 3D shapes such as microfluidic channels, curved shapes or micro-holes and alternatively photo-induced change of chemical or physical surface properties. Correct laser choice and process parameters enables new approaches for the fabrication of lab-on-chip devices with integrated functionalities. Laser-assisted ablation and modification of polystyrene (PS) is introduced with respect to the fabrication of polymer devices for high throughput planar patch clamping - a method of measuring the electrical activity of a cell currently a focus for high throughput systems (HTS). There are currently no marketed systems using novel materials that have surface modifications for either individual cell placement, or for dealing with cell networks, a physiologically important consideration for tissue engineering and understanding cell to cell interactions.
Within 4M, a design jointly proposed by FZK and Cranfield University for the fabrication of a polymer patch clamping system, laser micro-drilling of PS and subsequent surface functionalisation for cell adhesion has been investigated as a function of laser and process parameters. High power ArF laser with a pulse of 20 ns as well as high repetition ArF excimer laser sources with pulse lengths of 4-6 ns were used in order to study the influence of laser pulse length on laser drilling and laser induced surface modification. Micro-drilling of PS with diameters down to 1.5 μm have been demonstrated. Furthermore, localized formation of chemical structures suitable for improved single cell and cell network adhesion has been achieved on PS surfaces.