FLEXIBLE MANUFACTURE OF POLYMERIC TUBING INCLUDING FLOW-ALTERING STRUCTURES

• US 20160039121A1
• Filed: 08/05/2015
• Published: 02/11/2016
• Est. Priority Date: 08/05/2014
• Status: Active Grant

• Current Assignee: MiniPumps, LLC
• Original Assignee: Changgeng Liu
• Inventors: Jiang, Fukang, Dunn, Andrew, Liu, Changgeng
• Granted Patent: US 10,357,899 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: A61M 2207/00 Methods of manufacture, assembly or production
• CPC Class Codes: A61M 39/08 Tubes; Storage means specially adapted therefor
• CPC Class Codes: A61M 5/142 Pressure infusion, e.g. using pumps
• CPC Class Codes: A61M 5/14276 specially adapted for implantation
• CPC Class Codes: B29C 33/52 soluble or fusible in particular used in injection moulding B29C45/4457
• CPC Class Codes: B29C 41/02 for making articles of definite length, i.e. discrete articles
• CPC Class Codes: B29C 41/045 the axis being placed vertically, e.g. spin casting
• CPC Class Codes: B29C 41/42 Removing articles from moulds, cores or other substrates B29C33/444 and B29C37/0017 take precedence
• CPC Class Codes: B29K 2045/00 Use of polymers of unsaturated cyclic compounds having no unsaturated aliphatic groups in a side-chain, e.g. coumarone-indene resins or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2891/00 Use of waxes as mould material
• CPC Class Codes: B29K 2901/12 Thermoplastic materials
• CPC Class Codes: B29K 2905/08 Transition metals
• CPC Class Codes: B29K 2905/10 Copper
• CPC Class Codes: B29L 2031/753 Medical equipment; Accessories therefor bloodbags, medical bags B29L2031/7148; artificial eyes B29L2011/0008
• CPC Class Codes: C23F 1/00 Etching metallic material by chemical means manufacture of printing surfaces B41C; manufacture of printed circuits H05K
• CPC Class Codes: C23F 1/02 Local etching
• CPC Class Codes: C23F 1/18 for etching copper or alloys thereof

Abstract

Tubular polymeric structures are formed by creating a convex mold conforming to a fluid pathway design, depositing a coating of polymer over the mold, and in situ removing the mold without drawing it against the polymer. The resulting structures are fabricated with flow-altering features.

Claims

1. A method of forming a tubular polymeric structure, the method comprising the steps of:

forming a convex mold conforming to a fluid pathway design, the mold being formed of a material soluble in a solvent;

depositing a coating of polymer over the mold to form a coated structure, the parylene being unaffected by exposure to the solvent;

in situ removing the mold by subjecting the coated structure to the solvent to thereby release the tubular polymeric structure, the tubular polymer structure including a closed end; and

creating a flow-altering structure at the closed end.

2. The method of claim 1 wherein the material is wax.

3. The method of claim 1 wherein the material is a thermoplastic.

4. The method of claim 1 wherein the polymer is parylene.

5. The method of claim 1 wherein the mold is formed by 3D printing.

6. The method of claim 2 wherein the mold is formed into a block of support wax, and further comprising the step of dissolving the support wax but not the wax mold.

7. The method of claim 1 wherein, prior to deposition of the polymer, the molds undergo a smoothing process.

8. The method of claim 7 wherein the smoothing process comprises passing a solvent vapor over the mold.

9. The method of claim 7 wherein the smoothing process comprises spin coating and baking photoresist over the mold.

10. The method of claim 7 wherein the smoothing process comprises spray coating polyvinyl alcohol over the mold.

11. The method of claim 1 wherein the flow-altering structure comprises a plurality of apertures through the closed end to permit filtered fluid communication with a lumen of the tubular polymeric structure.

12. The method of claim 11 wherein the flow-altering structure is created by steps comprising (i) applying to the closed end a photoresist mask patterned to surround intended locations of the apertures and (ii) creating the apertures at the locations by etching.

13. The method of claim 12 wherein the etching is reactive-ion etching.

14. The method of claim 11 wherein the flow-altering structure is created by laser drilling the apertures.

15. The method of claim 14 further comprising disposing a laser-resistant mask on the closed end, the mask being patterned to surround intended locations of the apertures.

16. The method of claim 11 wherein the flow-altering structure is created by mechanically drilling the apertures.

17. A method of forming a tubular polymer structure, the method comprising the steps of:

bending a wire to conform to a fluid pathway design;

depositing a coating of polymer over the wire;

in situ removing the wire without drawing it against the polymer to thereby release the tubular polymeric structure, the tubular polymer structure including a closed end; and

creating a filter structure at the closed end.

18. The method of claim 17 wherein the wire is copper and the removing step comprises etching away the wire by exposure of the coated wire to an etchant.

19. The method of claim 18 wherein the etchant is ferrite chloride.

20. The method of claim 17 wherein the wire is made of a metal having a melting point lower than a melting point of the polymer.

21. The method of claim 20 wherein the wire is Field'"'"'s metal.

22. The method of claim 17 wherein the polymer is parylene.

23. The method of claim 17 further comprising the step of shaping a cross-section of the wire prior to the depositing step.

24. The method of claim 17 wherein the flow-altering structure comprises a plurality of apertures through the closed end to permit filtered fluid communication with a lumen of the tubular polymeric structure.

25. The method of claim 24 wherein the flow-altering structure is created by steps comprising (i) applying to the closed end a photoresist mask patterned to surround intended locations of the apertures and (ii) creating the apertures at the locations by etching.

26. The method of claim 25 wherein the etching is reactive-ion etching.

27. The method of claim 24 wherein the flow-altering structure is created by laser drilling the apertures.

28. The method of claim 27 further comprising disposing a laser-resistant mask on the closed end, the mask being patterned to surround intended locations of the apertures.

29. The method of claim 17 wherein the flow-altering structure is created by mechanically drilling the apertures.

30. A method of fabricating a drug pump, the method comprising the steps of:

forming a drug pump including a fluid reservoir and an ejection mechanism for forcing fluid therefrom;

forming a plurality of apertures through a wall of the reservoir; and

bonding a tubular conduit to the wall of the aperture such that a lumen of the conduit surrounds the apertures, actuation of the ejection mechanism forcing fluid from the reservoir and through the conduit via the apertures so as to filter the fluid.

31. An implantable pump comprising:

first and second walls forming a chamber therebetween, the first wall being expandable so as to vary a volume of the chamber;

a plurality of apertures through the second wall of the chamber;

an ejection mechanism for selectively expanding the first wall; and

a cannula bonded to an exterior face of the second wall such that a lumen of the cannula surrounds the apertures, actuation of the ejection mechanism forcing fluid from the chamber and through the cannula via the apertures so as to filter the fluid.