MIKROFLUIDVENTIL MIT ELEKTRISCHER ÖFFNUNGSSTEUERUNG

摘要

The microvalve has a flat support (12), with an inlet microchannel (14) and an outlet microchannel (16) made in the internal face of the support so an end of each microchannel opens near the other. A heat-sensitive material (18) is deposited on the internal face of the support between the ends. When the temperature of the material is raised by a heater (20), fluid flow is restored : The microvalve also includes a coating (22) fixed to the support (12). The heat-sensitive material is a thermofusible material such as a thermofusible polymer or glue. Alternatively, the heat-sensitive material is a thermoexpanding or thermoretracting material, or a pyrotechnic material such as a nitrocellulose- based material. The heater is a conducting route (20) with conducting zones (202, 203) and at least one heating zone (201) which is at least partially in contact with the heat-sensitive material deposit. The temperature rise is achieved by applying an electrical current to the conducting route. The heating zone is made of a resistive material or is a restriction in the conducting route. The thermoexpanding material is placed in a pit on the internal face of the support. The coating layer has a gap in the ends of the microchannels. The microvalve can also include means of evacuating gas. Independent claims are included for: (1) a method of making the microvalve by making the support containing the microchannels, depositing the heat-sensitive material and depositing the conducting route (or the conducting route and then the heat-sensitive material). A coating layer may be added by fixing a film to the support. The heat-sensitive material and the coating are fixed to the support by cold or hot lamination using a thermofusible glue; (2) a system including such a microvalve or a microvalve made using the method described; (3) opening a microvalve as described by applying an electrical current to the conducting route, raising the temperature of the heating zone, modifying the structure of the heat-sensitive material, at least partially unblocking the connection of the two microchannels and allowing fluid flow.