Microsampler and method of making the same

1. A microsampler comprising:

a chamber having a first inlet, wherein the chamber is under vacuum;

a first normally-opened (NO) valve comprising a first valve orifice in fluidic communication with the first inlet prior to activating the first NO valve, a first phase-change material disposed in proximity to the first valve orifice, and a first heating element disposed in proximity to the first phase-change material, wherein the first phase-change material substantially blocks the first valve orifice upon activating the first NO valve;

a first valve seat disposed above the first NO valve, wherein the first valve seat comprises a first seat opening; and

a first normally-closed (NC) valve disposed on the valve seat, wherein the first NC valve comprises a second phase-change material configured to substantially block the first seat opening prior to activating the first NC valve, and a second heating element disposed in proximity to the second phase-change material, wherein the second phase-change material substantially unblocks the first seat opening upon activating the first NC valve,

wherein the first NO valve is disposed between the chamber and the first NC valve.

2. The microsampler of claim 1 , wherein the first phase-change material and the second phase-change material comprises a solder or a metal alloy.

3. The microsampler of claim 1 , wherein activation of the first NO or NC valve comprises activating the first and/or second heating element, thereby heating the first and/or second phase-change material.

4. The microsampler of claim 3 , further comprising a first electrical connector configured to contact electrically the first heating element and a second electrical connector configured to contact electrically the second heating element.

5. The microsampler of claim 1 , wherein activating the first NO valve provides a hermetically sealed microsampler.

6. The microsampler of claim 1 , wherein the first valve seat comprises a top surface and a bottom surface, the top surface supports the first NC valve, and wherein the bottom surface is treated to promote wetting of the second phase-change material.

7. The microsampler of claim 1 , further comprising a cooler disposed beneath the chamber.

8. The microsampler of claim 7 , further comprising a heat sink disposed beneath the cooler.

9. An array comprising a plurality of microsamplers of claim 1 , wherein each microsampler is the same or different.

10. The array of claim 9 , wherein each microsampler is located in a recessed portion of a holder.

11. The array of claim 9 , wherein each chamber of each microsampler is defined in a substrate.

12. A microsampler comprising:

a chamber having a first inlet and a second inlet;

a first normally-opened (NO) valve comprising a first valve orifice in fluidic communication with the first inlet prior to activating the first NO valve, a first phase-change material disposed in proximity to the first valve orifice, and a first heating element disposed in proximity to the first phase-change material, wherein the first phase-change material substantially blocks the first valve orifice upon activating the first NO valve;

a first valve seat disposed above the first NO valve, wherein the first valve seat comprises a first seat opening;

a first normally-closed (NC) valve disposed on the valve seat, wherein the first NC valve comprises a second phase-change material configured to substantially block the first seat opening prior to activating the first NC valve, and a second heating element disposed in proximity to the second phase-change material, wherein the second phase-change material substantially unblocks the first seat opening upon activating the first NC valve;

a second NO valve comprising a second valve orifice in fluidic communication with the second inlet prior to activating the second NO valve, a third phase-change material disposed in proximity to the second valve orifice, and a third heating element disposed in proximity to the third phase-change material, wherein the third phase-change material substantially blocks the second valve orifice upon activating the second NO valve;

a second valve seat disposed above the second NO valve, wherein the second valve seat comprises a second seat opening; and

a second NC valve disposed on the second valve seat, wherein the second NC valve comprises a fourth phase-change material configured to substantially block the second seat opening prior to activating the second NC valve, and a fourth heating element disposed in proximity to the fourth phase-change material, wherein the fourth phase-change material substantially unblocks the second seat opening upon activating the second NC valve.

13. The microsampler of claim 12 , wherein the chamber comprises one or more baffling structures.

14. The microsampler of claim 12 , further comprising a pumping system in fluidic connection with the second inlet upon activating the second NC valve.

15. A method of fabricating a microsampler, the method comprising:

depositing one or more electrical connectors and/or solder pads on a valve plate disposed above a chamber;

forming a first heating element in electrical contact with the one or more electrical connectors and/or solder pads;

defining a valve orifice within the valve plate and in proximity to the heating element;

depositing a first phase-change material in proximity to the valve orifice and the heating element, thereby providing a valved chamber comprising a normally-opened (NO) valve; and

attaching a valved seat to the valved chamber, wherein the valved seat comprises a normally-closed (NC) valve disposed on a valve seat and wherein the NO valve is disposed between the chamber and the NC valve.

16. The method of claim 15 , wherein the depositing the first phase-change material comprises depositing a solder or a metal alloy in proximity to the valve orifice.

17. The method of claim 16 , wherein the depositing the first phase-change material comprises forming an annular ring comprising the solder or metal alloy and aligning the valve orifice with a hole located within the annular ring.

18. The method of claim 15 , wherein the valved chamber is provided in a bottom layer of a substrate.

19. The method of claim 15 , wherein the attaching the valved seat to the valved chamber comprises disposing the valved seat in a top layer of a substrate.

20. A microsampler comprising:

a chamber having a first inlet, wherein the chamber is under vacuum;

a body having a distal end and a peripheral end, wherein the body defines the chamber;

a base plate affixed to the peripheral end of the body;

a lower valve plate affixed to the distal end of the body, wherein the first valve plate comprises the first inlet;

a first normally-opened (NO) valve disposed on the first valve plate, wherein the first NO valve comprises a first valve orifice in fluidic communication with the first inlet prior to activating the first NO valve, a first phase-change material disposed in proximity to the first valve orifice, and a first heating element disposed in proximity to the first phase-change material, wherein the first phase-change material substantially blocks the first valve orifice upon activating the first NO valve;

a first valve seat disposed above the first NO valve, wherein the first valve seat comprises an upper valve plate and a first seat opening disposed in the upper valve plate;

a fitting disposed between the lower valve plate and the upper valve plate; and

a first normally-closed (NC) valve disposed on the valve seat of the upper valve plate, wherein the first NC valve comprises a second phase-change material configured to substantially block the first seat opening prior to activating the first NC valve, and a second heating element disposed in proximity to the second phase-change material, wherein the second phase-change material substantially unblocks the first seat opening upon activating the first NC valve,

wherein the first NO valve is disposed between the chamber and the first NC valve.