| 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.
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