Use of Freeze-Thaw Flow Management for Controlling and Switching Fluid Flow in Capillary Tubes

We report an improved demonstration of a new method for many flow in capillaries or narrow channels. By freezing and thawing the contents of a small section of the tube, it is possible to make the fluid act as its own shutoff valve. By so directing flow to a second capillary, we have shown that this approach can be employed to form the basis of an innovative flow switching technique. No moving parts are required, and the switch element contributes no effective void volume