| 摘要 |
A valve for controlling fluid flow in a microfluidic device is provided. The valve comprises a chamber 26 formed on a substrate 24, a heating coil 42, and a valve material 30 contained in the chamber 26. When the valve is to be closed, the heating coil is activated causing the valve material to expand out of the chamber, through a neck portion 28, and into the main channel 22, blocking it. Preferably, the valve material is paraffin wax, and is caused to melt by the heating coil 42. On melting the melted paraffin wax flows into the main channel whereupon it cools and solidifies. A restriction 34, with collar 36 provides a cool surface on which the solidifying wax accumulates. |
