Bonding of a complicated polymer microchannel system for study of pressurized liquid flow characteristics with the electric double effect

Abstract

Liquid flow characteristics with the electric double-layer (EDL) effect are studied in a microchannel made by polymer materials. The microchannel is integrated with arrays of a polymer pressure sensor for measurements of the local pressure distribution inside the channel. The bonding of this complicated microchannel requires special caution not only to ensure good contact between the channel walls and the cover plate leading to correct height of a channel but also to avoid liquid leakage at higher pressure. A bonding technique is developed in this work, which can be readily applied in a complicated lab-on-chip system for the study of micro-fluid behavior. The completed channel system with arrays of micro pressure sensors is used to study both the entry and fully developed flow of pure water. The accurate measurements of the pressure distribution along the channel clarify many of the conflicting issues reported in the microchannel flow system. It is found that the friction factor of liquid flow in the microchannel agrees well with the prediction accounting for the aspect ratio of the channel. The EDL effect on the local pressure drop, which may frequently occur in the liquid flow system, is also discussed and presented.