surface engineering of microfluidic devices
The table below shows how oxygen plasma surface treatment can be used to produce hydrophilic surfaces and the combinations of hydrophilic and hydrophobic surfaces within a channel and how different regions of a device can be given different wetting characteristics. The hydrophilic surfaces can be readily coated by passing solutions through the channels for example proteins and can be used for culturing biological cells. A range of polymers can be adsorbed onto the surfaces to give surface charge or provide molecular loops and chains to sterically inhibit fouling of the channel walls. Alternatively sheathed flow can be used to provide a liquid barrier to wall contact.
A hydrophobic coating can be applied that increases the contact angle to 110.6 deg.