Selective Surface Patterning with an Electric Discharge in the Fabrication of Microfluidic Structures

✍ Scribed by Niina M. Suni; Markus Haapala; Ari Mäkinen; Lauri Sainiemi; Sami Franssila; Elina Färm; Esa Puukilainen; Mikko Ritala; Risto Kostiainen

• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 538 KB
• Volume: 120
• Category: Article
• ISSN: 0044-8249
• DOI: 10.1002/ange.200801569

✦ Synopsis

Surfaces with micro-and nanoscale patterns are attracting wide interest for their potential use in, for example, sensors, data storage, displays, optoelectronics, biomimetics, and micro-and nanofluidics. An attractive method to manipulate substrate properties easily and with good controllability is selective surface modification with self-assembled monolayers (SAMs). Selective modification of SAMs is possible through selective placement, for example, by microcontact printing (mCP) [1] and dip-pen nanolithography (DPN), [2] or by selective removal of the monolayer constituents, for example, by energetic beams (photons, electrons, atoms, ions) [3][4][5][6] or scanning probe lithography (SPL). [7] mCP is a rapid and simple technique but, even though successfully applied to curved substrates, [8] as a contact stamping method it does not tolerate textured surfaces. DPN and SPL are high-resolution techniques but neither can handle high-relief structures. In addition, these techniques are slow in scanning large areas and require expensive equipment. Bombardment with energetic beams is relatively fast and better suited for textured surfaces. However, these methods tend to need masks, complex setups, special equipment, or a vacuum environment.

Herein, we report the exploitation of an electric discharge for selective surface modification of a hydrophobic trichloro-(octadecyl)silane (ODS) SAM on a Si-SiO 2 surface. Electric discharge is widely utilized in the micromachining of metal, glass, and semiconductor substrates. Microelectro discharge