Plastic Microfluidic Devices Modified With Polyelectrolyte Multilayers

Published

October 15, 2000

Author(s)

S L. Barker, Michael J. Tarlov, H E. Canavan, J J. Hickman, Laurie E. Locascio

Abstract

Control of the polymer surface chemistry is a crucial aspect of development of plastic microfluidic devices. When commercially available plastic substrates are used to fabricate microchannels, differences in the EOF mobility from plastic to plastic can be very high. Therefore, we have used polyelectrolyte multilayers (PEMs) to alter the surface of microchannels fabricated in plastics. Optimal modification of the microchannel surfaces was obtained by coating the channels with alternating layers of poly(allylamine hydrochloride) and poly(styrene sulfonate). Polystyrene (PS) and polyethylene terephthalate glycol (PETG) were chosen as substrate materials because the significant differences in the polymer chemistries and in the EOF of channels fabricated in these two plastic materials. The efficacy of the surface modification has been evaluated using XPS and by measuring the electroosmotic flow mobility. When microchannels prepared in both PS and PETG are modified with PEMs, they demonstrate very similar electroosmotic mobilities. The PEMs are easily fabricated and provide a means for controlling the flow direction and the electroosmotic mobility in the channels. The PEMs coated microchannels have excellent wettability, allowing facile filling of the channels. In addition, the PEMs produce reproducible results and are robust enough to withstand long term storage.

Citation

Analytical Chemistry

Volume

72

Issue

No. 20

Pub Type

Journals

Keywords

electroosmotic, microchannel, microfluidics, multilayer, PETG, plastic, polyelectrolyte, polystyrene

Citation

Barker, S. , Tarlov, M. , Canavan, H. , Hickman, J. and Locascio, L. (2000), Plastic Microfluidic Devices Modified With Polyelectrolyte Multilayers, Analytical Chemistry (Accessed August 31, 2025)