Method of Making a Membrane for Use with a Flow Control System for a Micropump

• US 20110309552A1
• Filed: 06/30/2011
• Published: 12/22/2011
• Est. Priority Date: 02/12/2009
• Status: Active Grant

• Current Assignee: PicoLife Technologies, LLC
• Original Assignee: PicoLife Technologies, LLC
• Inventors: Amirouche, Farid, Cantwell, Matthew
• Granted Patent: US 8,663,538 B2
• Time in Patent Office: Days
• US Class Current: 264/331.11
• CPC Class Codes: A61M 2039/2453 not being fixed to the valve body
• CPC Class Codes: A61M 2205/0244 Micromachined materials, e.g. made from silicon wafers, microelectromechanical systems [MEMS] or comprising nanotechnology
• CPC Class Codes: A61M 39/24 Check- or non-return valves
• CPC Class Codes: A61M 5/1422 with double acting or multiple pistons
• CPC Class Codes: A61M 5/14224 Diaphragm type
• CPC Class Codes: A61M 5/16804 Flow controllers
• CPC Class Codes: F04B 43/043 Micropumps
• CPC Class Codes: Y10T 137/7879 Resilient material valve
• CPC Class Codes: Y10T 137/86002 Fluid pressure responsive
• CPC Class Codes: Y10T 137/86019 Direct response valve
• CPC Class Codes: Y10T 29/49996 Successive distinct removal operations

Abstract

A method of making a membrane for use with a flow control system is disclosed. A female mold body portion and a male mold body portion are provided. A body portion support member configured to receive at least a portion of the female body portion and at least a portion of the male body portion is provided. The female and male body portions are separated from one another. Membrane manufacturing material is provided to a concave portion of the female mold body portion. The sleeve is moved downward. The lower mold portion is lowered until it is just short of its final intended position. Excess membrane manufacturing material, if any, is removed from around the seam of the mold. The upper mold portion is lowered the remaining distance so that the two mold portions are separated by the exact distance desired for the final membrane thickness.

Claims

1. A method of making a membrane for use with a flow control system comprising:

providing a mold female body portion having a cylindrical elongate lower portion extending along an axis and having a diameter D, and a centered, concave upper face having substantially the same diameter D and having a radius of curvature R, the upper face being oriented substantially perpendicularly to the axis of the elongate lower portion and extending therefrom, in a substantially vertical, upwardly extending position;

providing a male mold body portion having a cylindrical elongate upper portion with a lower terminus extending along an axis, the upper portion thereof having a diameter substantially equal to D and a central cylindrical portion having a height H extending from the lower terminus along the axis of the upper portion, the central portion has a diameter of D−

G, wherein G is the annular thickness of a spacing gap extending radially outward from the central portion, the male mold body portion further having a centered, convex lower face having a diameter substantially equal to D−

G, a radius of curvature substantially equal to R and being oriented substantially perpendicularly to the axis of the elongate upper portion;

downwardly to within a predetermined distance Th from the female body portion;

providing a body portion support member having a generally elongated, tubular configuration and further having an inner diameter slightly greater than D, the body portion support member being configured to receive at least a portion of the female body portion and at least a portion of the male body portion, so that the female and male body portions are maintainable along the same axis and the convex face and concave face are positioned in cooperative relation with one another;

separating the female and male body portions from one another and lubricating each with a lubricant;

providing a sufficient amount of membrane manufacturing material to the concave portion of the lower portion of the female mold body portion;

moving the sleeve down the shaft to cover the joint between the upper and lower half of the mold;

dropping the lower mold portion until it is 0.005″

short of its final intended position;

removing any excess membrane manufacturing material from around the seam of the mold;

dropping the upper mold portion the remaining distance so that the two mold portions are separated by the exact distance desired for the final membrane thickness;

heating the assembly to a desired temperature T_heat for a desired time t_heat;

allowing the assembly to cool for a desired time t_cool;

removing the membrane.

2. The method of making a membrane of claim 1, wherein D is about 0.25 inches and G is about 0.025 inches.

3. The method of making a membrane of claim 1, wherein D is about 0.1875 inches and G is about 0.020 inches.

4. The method of making a membrane of claim 1, wherein the premixed membrane manufacturing material is Sylgard 184.

5. The method of making a membrane of claim 1, wherein the premixed membrane manufacturing material is Silastic Q7-4750.

6. The method of making a membrane of claim 1, wherein the premixed membrane manufacturing material is Silastic Q7-4840.

7. The method of making a membrane of claim 1, wherein the premixed membrane manufacturing material is further prepared by mixing it in a prescribed ratio of A:

B (base to reagent) and allowing it to sit for predetermined time T_sit sufficient to allow the substantial majority of air bubbles to exit the surface.

8. The method of making a membrane of claim 7, wherein the premixed membrane manufacturing material is Sylgard 184 and A:

B is about 10;

1.

9. The method of making a membrane of claim 7, wherein the premixed membrane manufacturing material is Silastic Q7-4840 and A:

B is about 1;

1.

10. The method of making a membrane of claim 7, wherein T_sit is about ten minutes.

11. The method of making a membrane of claim 8, wherein T_sit is about ten minutes.

12. The method of making a membrane of claim 9, wherein T_sit is about ten minutes.

13. The method of making a membrane of claim 1, wherein the premixed membrane manufacturing material is Sylgard 184 and Th is about 0.010.

14. The method of making a membrane of claim 1, wherein the premixed membrane manufacturing material is Silastic Q7-4750 and Th is about 0.015.

15. The method of making a membrane of claim 1, wherein the premixed membrane manufacturing material is Silastic Q7-4840 and Th is about 0.013.

16. The method of making a membrane of claim 1, wherein the lubricant is silicone.

17. The method of making a membrane of claim 1, wherein the premixed membrane manufacturing material is Sylgard 184, T is about 300 F and t is about 14 minutes.

18. The method of making a membrane of claim 1, wherein the premixed membrane manufacturing material is Silastic Q7-4840, T is about 302 F, and t is about 5 minutes.

19. The method of making a membrane of claim 1, wherein t_cool, is about two minutes.

20. A method of making a membrane for use with a flow control system comprising:

providing a mold female body portion having a cylindrical elongate lower portion extending along an axis and having a diameter D equal to about 0.1875 inches, and a centered, concave upper face having substantially the same diameter D and having a radius of curvature R, the upper face being oriented substantially perpendicularly to the axis of the elongate lower portion and extending therefrom, in a substantially vertical, upwardly extending position;

providing a male mold body portion having a cylindrical elongate upper portion with a lower terminus extending along an axis, the upper portion thereof having a diameter substantially equal to D and a central cylindrical portion having a height H extending from the lower terminus along the axis of the upper portion, the central portion has a diameter of D−

G, wherein G is about 0.020 inches and is the annular thickness of a spacing gap extending radially outward from the central portion, the male mold body portion further having a centered, convex lower face having a diameter substantially equal to D−

G, a radius of curvature substantially equal to R and being oriented substantially perpendicularly to the axis of the elongate upper portion;

downwardly to within a predetermined distance Th from the female body portion, wherein Th is about 0.013 inches;

providing a body portion support member having a generally elongated, tubular configuration and further having an inner diameter slightly greater than D, the body portion support member being configured to receive at least a portion of the female body portion and at least a portion of the male body portion, so that the female and male body portions are maintainable along the same axis and the convex face and concave face are positioned in cooperative relation with one another;

separating the female and male body portions from one another and lubricating each with a silicone lubricant;

premixing a sufficient amount of membrane manufacturing material in a ratio of 1;

1 (base to reagent) and allowing it to sit for about ten minutes;

providing a sufficient amount of the premixed membrane manufacturing material to the concave portion of the lower portion of the female mold body portion;

moving the sleeve down the shaft to cover the joint between the upper and lower half of the mold;

dropping the lower mold portion until it is about 0.005 inches short of its final intended position;

removing any excess membrane manufacturing material from around the seam of the mold;

dropping the upper mold portion the remaining distance so that the two mold portions are separated by the exact distance desired for the final membrane thickness;

heating the assembly to a desired temperature of about 302 F for a desired time of about 5 minutes;

allowing the assembly to cool for a desired time of about two minutes; and

removing the membrane.