Maskless stereo lithography method and apparatus for freeform fabrication of 3-D objects

• US 20030173713A1
• Filed: 12/10/2001
• Published: 09/18/2003
• Est. Priority Date: 12/10/2001
• Status: Abandoned Application

• Current Assignee: Wen-Chiang Huang
• Original Assignee: Wen-Chiang Huang
• Inventors: Huang, Wen-Chiang
• Application Number:
  US10/007,570
• Publication Number:
  US 20030173713A1
• Time in Patent Office: Days
• US Class Current: 264/401
• CPC Class Codes: B29C 2035/0827 using UV radiation
• CPC Class Codes: B29C 2035/0838 using laser
• CPC Class Codes: B29C 2035/0844 using X-ray
• CPC Class Codes: B29C 2035/085 using gamma-ray
• CPC Class Codes: B29C 2037/903 by means of a computer
• CPC Class Codes: B29C 35/0866 using particle radiation
• CPC Class Codes: B29C 64/124 using layers of liquid which are selectively solidified
• CPC Class Codes: B29C 64/135 the energy source being concentrated, e.g. scanning lasers or focused light sources
• CPC Class Codes: B29C 64/165 using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber
• CPC Class Codes: B29K 2105/251 Particles, powder or granules expandable particles B29K2105/046
• CPC Class Codes: B29K 2705/00 Use of metals, their alloys or their compounds, for preformed parts, e.g. for inserts
• CPC Class Codes: B29K 2709/02 Ceramics
• CPC Class Codes: G03F 7/0037 Production of three-dimensional images

Abstract

A maskless stereo lithography method and apparatus for forming a three-dimensional object from a plurality of adhered laminae by exposing successive layers of a photo-curable material to a micro-focused energy beam generated by an array of Fresnel zone plates. The method includes the steps of (A) providing a controllable array of Fresnel zone plates; (B) forming a layer of material adjacent to any last formed layer of material in preparation for forming a subsequent lamina of the object; (C) exposing the material to the micro-focused energy beam to form the subsequent lamina of the object; and (D) repeating the steps of forming and exposing a plurality of times in order to form the object from a plurality of adhered laminae, wherein the array of Fresnel zone plates are employed to focus parallel beamlets of energy beam from a source so that the beamlets converge to an array of focal points at predetermined positions of a lamina in accordance with a computer-aided design file of the object.

Claims

1. A maskless stereolithography method of forming a three-dimensional object from a plurality of adhered laminae by exposing successive layers of a material to a micro-focused energy beam generated by an array of Fresnel zone plates, comprising:

(A) providing a controllable array of Fresnel zone plates;

(B) forming a layer of material adjacent to any last formed layer of material in preparation for forming a subsequent lamina of the object;

(C) exposing the material to the micro-focused energy beam to form the subsequent lamina of the object; and

(D) repeating the steps of forming and exposing a plurality of times in order to form the object from a plurality of adhered laminae,

wherein the array of Fresnel zone plates are employed to focus parallel beamlets of energy beam from a source so that said beamlets converge to an array of focal points at predetermined positions of a lamina in accordance with a computer-aided design file of said object.

2. The method of claim 1 further comprising a step of operating means for modulating individual ones of said array of focal points.

3. The method of claim 2, wherein said modulating means operates to selectively shut off and on said focal points.

4. The method of claim 1, wherein said step of forming a layer of material comprises coating or re-coating a thin layer of photo-curable resin.

5. The method of claim 1, wherein said step of forming a layer of material comprises coating or re-coating a thin layer of a material composition comprising a photo-curable resin and fine ceramic and/or metallic particles.

6. The method of claim 5, wherein said fine ceramic and/or metallic particles occupy at least 40% by volume of said composition.

7. The method of claim 1, wherein said step of forming a layer of material comprises feeding a layer of fine ceramic and/or metallic powder particles and, concurrently or sequentially, spraying a predetermined amount of a photo-curable resin onto said layer of powder particles.

8. The method of claim 1, wherein said energy beam is selected from the group consisting of ultraviolet, laser, X-ray, Gamma-ray, atomic particle beam, or a combination thereof.

9. An apparatus for forming a three-dimensional object from a plurality of adhered laminae by exposing successive layers of a photo-curable material composition to a micro-focused energy beam, comprising:

(a) a work surface to support the object while being built;

(b) material dispensing means disposed a distance from said work surface for feeding successive layers of a photo-curable material composition thereon, one layer at a time;

(c) a Fresnel zone plate sub-system disposed a distance above said successive layers of a photo-curable material composition for focusing an energy beam into an array of focal points to create a curing pattern on each of said successive layers for forming multiple laminae of said object;

(d) a Fresnel zone plate controller comprising modulating means and being electronically connected to said Fresnel zone plate sub-system;

(e) motion devices coupled to said work surface, said Fresnel zone plate sub-system, and/or said material-dispensing means for moving said material-dispensing means and said Fresnel zone plate sub-system relative to said work surface in a plane defined by first and second directions and in a third direction orthogonal to said plane to dispense and cure said successive layers of a photo-curable material composition, one layer at a time, for forming said 3-D object.

10. The apparatus of claim 9, further comprising a computer that controls the operation of said Fresnel zone plate sub-system.

11. The apparatus of claim 9, further comprising motion control means electronically connected to said motion devices to control the operation of said motion devices.

12. The apparatus of claim 9, wherein said energy beam comprises X-radiation.

13. The apparatus of claim 9, wherein said modulating means comprises micro-mechanical shutters.

14. The apparatus of claim 9, wherein said modulating means comprises micro-mechanical mirrors.

15. The apparatus of claim 9, wherein said material dispensing means comprises:

a vat to contain the photo-curable material composition;

a moveable support platform disposed a distance from said vat, said platform providing a work surface on which said object is supported while being built; and

coating means disposed a distance from said work surface for feeding said successive layers of a photo-curable material composition thereto, one layer at a time.

16. The apparatus of claim 9, wherein said material dispensing means comprises:

powder-dispensing means having an outlet directed to said work surface for feeding successive layers of powder particles onto said work surface one layer at a time; and

adhesive sprayer means having an outlet directed to said successive layers of powder particles for spraying a layer of a photo-curable resin onto each of said successive layers of powder particles for forming said successive layers of a photo-curable material composition.