Structured Porosity or Controlled Porous Architecture Metal Components and Methods of Production

• US 20110172798A1
• Filed: 08/24/2009
• Published: 07/14/2011
• Est. Priority Date: 09/04/2008
• Status: Abandoned Application

• Current Assignee: Mark Staiger, Timothy Bryan Francis Woodfield
• Original Assignee: Mark Staiger, Timothy Bryan Francis Woodfield
• Inventors: Staiger, Mark, Woodfield, Timothy Bryan Francis
• Application Number:
  US13/062,352
• Publication Number:
  US 20110172798A1
• Time in Patent Office: Days
• US Class Current: 700/98
• CPC Class Codes: A61L 2400/18 Modification of implant surfaces in order to improve biocompatibility, cell growth, fixation of biomolecules, e.g. plasma treatment
• CPC Class Codes: A61L 27/04 Metals or alloys
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: C22C 1/02 by melting C22C1/1036 takes precedence
• CPC Class Codes: C22C 1/026 Alloys based on aluminium
• CPC Class Codes: C22C 1/08 Alloys with open or closed pores
• CPC Class Codes: C22C 1/082 with removal of the preform
• CPC Class Codes: C22C 21/06 with magnesium as the next major constituent
• CPC Class Codes: C22C 23/02 with aluminium as the next major constituent

Abstract

A method of forming a product such as a biomedical implant of Mg or Al includes computationally designing the product including a controlled porous architecture, producing a positive model of the product, infiltrating the model with a salt-containing paste, drying the paste, removing the material comprising the positive model leaving a negative salt template, infiltrating the salt template with molten Mg or Al or alloy, allowing the Mg or Al or alloy to solidify, and removing the salt template to leave the Mg or Al or alloy product with the controlled porous architecture. In some embodiments the method includes controlling the Mg or Al infiltration pressure to control the extent to which a texture or pattern of the internal surfaces of the model is imprinted on the internal surfaces of the end product.

Claims

1. A method of forming a product of Mg or Al or an alloy thereof, having interconnected porosity, comprising the steps of:

computationally designing the product including a controlled porous architecture of interconnected porosity within the product,

producing a positive model of the product including said controlled porous architecture using rapid prototyping,

infiltrating the positive model with a salt-containing paste and drying the paste,

removing the material comprising the positive model, leaving a negative salt template,

infiltrating the salt template with molten Mg or Al or alloy and then allowing the Mg or Al or alloy to solidify, and

removing the salt template to leave the Mg or Al or alloy product with said structured porosity or controlled porous architecture.

2. A method according to claim 1 including computationally designing the product so that the controlled porous architecture of the model is also ordered in at least in one direction through at least part of the model.

3. A method according to claim 1 including computationally designing the product so that the controlled porous architecture of the model is ordered in at least two directions through at least part of the model.

4. A method according to claim 1 including computationally designing the product so that the controlled porous architecture of the model is ordered in three directions through at least part of the model.

5. A method according to claim 1 including computationally designing the external shape of the product and the internal controlled porous architecture in a predetermined orientation relative to the external shape of the product.

6. A method according to claim 1 including computationally designing the product to comprise a constant porosity through the product.

7. A method according to claim 1 including computationally designing the product to comprise a varying porosity through the product.

8. A method according to claim 1 including computationally designing the product so that the porosity of the product varies in at least in one direction through at least part of the model.

9. A method according to claim 1 including computationally designing the product so that porosity of the product varies in at least two directions through at least part of the model.

10. A method according to claim 1 including computationally designing the product so that the porosity of the product varies in three directions through at least part of the model.

12. A method according to claim 1 including computationally designing the product to comprise a predetermined surface topography on at least part of the internal surfaces of the model.

13. A method according to claim 1 including producing the positive model of the product by causing a machine to produce the model in a series of machine steps and under control of a computer and based on a computer representation of the product design to build up the model in a layer-by-layer process.

14. A method according to claim 13 including producing the positive model of the product using rapid prototyping including stereolithography.

15. A method according to claim 14 including building up the positive model in a layer-by-layer process from a UV-curable resin.

16. A method according to claim 13 including producing the positive model of the product using rapid prototyping including 3-D printing.

17. A method according to claim 1 including controlling the pressure of said infiltrating of the positive model with a salt-containing paste to control the extent to which a surface topography of the internal surfaces of the model is imprinted on the internal surfaces of the product.

24. A method according to according to claim 1 wherein the product is a biomedical implant.

25. A method according to claim 1 wherein the product is an orthopaedic implant.

26. A method according to claim 1 wherein the product is a tissue scaffold for supporting tissue formation and repair.

27. A method according to claim 25 including computationally designing the product to comprise porosity variations through the orthopaedic implant such that different parts of the orthopaedic implant will degrade in situ in the body at different rates.

35. A method according to claim 26 including computationally designing the product to comprise porosity variations through the tissue scaffold such that different parts of the tissue scaffold will degrade in situ in the body at different rates.

11. (canceled)

18-23. -23. (canceled)

28-29. -29. (canceled)

30. A method of forming a medical implant interconnected porosity, comprising the steps of:

computationally designing the implant including the external shape of the implant and a controlled porous architecture in a predetermined orientation relative to the external shape of the implant,

producing a positive model of the implant including said controlled porous architecture by causing a machine to produce the model in a series of machine steps and under control of a computer and based on a computer representation of the implant design to build up the model,

infiltrating the positive model with a salt-containing paste and drying the paste,

removing the material comprising the positive model, leaving a negative salt template,

infiltrating the salt template with molten Mg or Al or alloy and then allowing the Mg or Al or alloy to solidify, and

removing the salt template to leave the Mg or Al or alloy implant with said structured porosity or controlled porous architecture.

31. A method of forming a medical implant interconnected porosity, comprising the steps of:

computationally designing the implant including the external shape of the implant and a controlled porous architecture in a predetermined orientation relative to the external shape of the implant,

producing a positive model of the implant including said controlled porous architecture by causing a machine to produce the model in a series of machine steps and under control of a computer and based on a computer representation of the implant design to build up the model in a layer-by-layer process,

infiltrating the positive model with a salt-containing paste and drying the paste and controlling the pressure of said infiltrating to control the extent to which a texture or pattern of the internal surfaces of the model is imprinted on the internal surfaces of the implant,

removing the material comprising the positive model, leaving a negative salt template,

infiltrating the salt template with molten Mg or Al or alloy and then allowing the Mg or Al or alloy to solidify, and

removing the salt template to leave the Mg or Al or alloy implant with said structured porosity or controlled porous architecture.

32-34. -34. (canceled)