Valves, valved fluid transfer devices and ambulatory infusion devices including the same

1. A valve, comprising:

a first valve layer defining a valve seat; and

a second valve layer, associated with the first valve layer, defining a valve element movable relative to the valve seat between a closed position where the valve element engages the valve seat to prevent flow past the valve seat and an open position where the valve element is in spaced relation to the valve seat to allow flow past the valve seat;

wherein one of the valve seat and the valve element includes a main portion that is formed from a first material and a seal portion that is formed from a second material that is less tacky than the first material and that is in contact with the other of the valve seat and the valve element when the valve element is in the closed position.

2. The valve as claimed in claim 1 , wherein

the second valve layer abuts the first valve layer.

3. The valve as claimed in claim 1 , wherein

the second valve layer includes a base portion; and

the valve seat extends away from the base portion.

4. The valve as claimed in claim 3 , wherein

the valve seat tapers with distance from the base portion.

5. The valve as claimed in claim 3 , wherein

a gap is defined between the base portion and the valve element when the valve element is in the closed position.

6. The valve as claimed in claim 1 , wherein

the valve seat defines a pointed end; and

the valve element engages the pointed end of the valve seat to prevent flow through the opening when in the closed position.

7. The valve as claimed in claim 1 , wherein the first material comprises an elastomeric material selected from the group consisting of silicone rubber, latex rubber, fluoropolymers, urethane, butyl rubber, and isoprene.

8. The valve as claimed in claim 1 , wherein

the main portion is formed from an elastomeric material; and

the seal portion is selected from the group consisting of

a layer of silicon suboxide on the main portion,

a relatively thin layer of a relatively hard elastomeric material,

a relatively thin layer of a fluoroelastomer or a low friction protective coating, and

a coating of a filler material.

9. The valve as claimed in claim 8 , wherein

the valve element includes the main portion and the seal portion that is less tacky than the main portion.

10. The valve as claimed in claim 8 , wherein

the first valve layer comprises a first patterned valve layer; and

the second valve layer comprises a second patterned valve layer.

11. The valve as claimed in claim 1 , wherein

the main portion is formed from an elastomeric material; and

the seal portion is selected from the group consisting of

a surface of the valve seat main portion that has been halogenated,

a surface of the valve seat main portion that has been implanted with ions of a ceramic material or ions of a metal material or ions of a metal oxide material, and

a surface of the valve seat main portion that has been implanted and coated with ions of a ceramic material or ions of a metal material or ions of a metal oxide material.

12. The valve as claimed in claim 11 , wherein

the valve element includes the main portion and the seal portion that is less tacky than the main portion.

13. The valve as claimed in claim 11 , wherein

the first valve layer comprises a first patterned valve layer; and

the second valve layer comprises a second patterned valve layer.

14. The valve as claimed in claim 1 , wherein

the valve element includes a first side that engages the valve seat and a second side opposite the first side; and

the second side is exposed to reservoir pressure from a reservoir.

15. The valve as claimed in claim 1 , wherein

the valve element includes the main portion formed from the first material and the seal portion formed from the second material that is less tacky than the main portion.

16. The valve as claimed in claim 1 , wherein

the valve element faces the opening and is aligned with the opening when the valve element is in the open position; and

the valve element faces the opening and is aligned with the opening when the valve element is in the closed position.

17. The valve as claimed in claim 1 , wherein

at least one of the first and second valve layers comprises a patterned valve layer.

18. The valve as claimed in claim 1 , wherein

the first valve layer comprises a first patterned valve layer; and

the second valve layer comprises a second patterned valve layer.

19. The valve as claimed in claim 1 , wherein

the valve element is biased to the closed position.