Sealable microvalve that can be repeatedly opened and sealed
A substantially leak-free, sealable microvalve that can be repeatedly opened and sealed is presented. The resealable microvalve includes a block with a through via and a sealing plate. The gap between the block and the sealing plate is sealed by a sealing material. The sealing material can be melted when heat is applied and can be solidified when heat is absent. To close the resealable microvalve, heat is applied by flowing a current through a resistive heater and an actuator brings the block and the sealing plate into a contacting position. By removing the heat, the sealing material is solidified and creates a sealed state. To open the resealable microvalve, heat is applied to the sealing material. When the sealing material melts, the actuator moves the block and the sealing plate into a spaced apart position.
1. A resealable microvalve comprising:
first and second plates in facing relationship, wherein at least one of the first and second plates is capable of movement from a first spaced apart position to a second contacting position, the first plate comprising a through via;
a first wetting element disposed on the first plate and surrounding the through via;
a second wetting element disposed on the second plate in facing relationship with the first wetting element;
a sealing material disposed on one or both of the first and second wetting elements, the sealing material capable of reversible melt and solidification and of wetting the first and second wetting elements when in a molten state; and
a heating element in thermal communication with the sealing material, wherein the heating element is positioned on at least one of the first and second plates;
wherein at least one of the first and second plates is supported on a leak-proof structure;
wherein a surface of the first plate surrounding the first wetting element has a non-wetting interaction with the sealing material, and
wherein a surface of the second plate surrounding the second wetting element has a non-wetting interaction with the sealing material.
2. The microvalve of claim 1 , wherein the heating element comprises a resistive heater.
3. The microvalve of claim 1 , wherein the first plate is supported on a thermally insulating membrane.
4. The microvalve of claim 3 , wherein the first plate is at least partially surrounded by a thermal insulator.
5. The microvalve of claim 4 , wherein the thermal insulator is air or a thermally insulating material.
6. The microvalve of claim 1 , further comprising an actuator for moving the first and second plates between the first spaced apart position and the second contacting position.
7. The microvalve of claim 6 , wherein the actuator is piezoelectric, electromagnetic, electrostatic, or thermopneumatic.
8. The microvalve of claim 7 , wherein the piezoelectric actuator comprises electrodes covering a portion of the actuator.
9. The microvalve of claim 6 , wherein the actuator is supported on thermally insulating tethers.
10. The microvalve of claim 6 , wherein the actuator is coupled to the second plate and the heating element is placed on a surface of the first plate.
11. The microvalve of claim 10 , wherein the first plate is comprised of a thermally conducting material.
12. The microvalve of claim 6 , wherein the second plate is supported on a thermally insulating membrane.
13. The microvalve of claim 12 , wherein the second plate is at least partially surrounded by a thermal insulator.
14. The microvalve of claim 13 , wherein the thermal insulator is air or a thermally insulating material.
15. The microvalve of claim 12 , wherein the first plate is supported on a thermally insulating membrane and the actuator is coupled to the thermally insulating membrane.
16. The microvalve of claim 12 , wherein the actuator is coupled to the first plate and the heating element is placed on the surface of the first plate.
17. The microvalve of claim 12 , wherein the second plate is a thermally insulating membrane.
18. The microvalve of claim 1 , further comprising:
first and second frames supporting the first and second plates; and
a connector coupling the first and second frames.
19. A method of sealing a resealable microvalve, the method comprising:
providing a resealable microvalve according to claim 1 ;
heating the sealing material to melt the sealing material;
moving the first and second plates from the first spaced apart position to the second contacting position, wherein the molten sealing material wets the surfaces of the first and second wetting elements to form a molten seal; and
cooling the molten seal to resolidify the sealing material and forming a gas-tight seal.