Methods for manufacturing three-dimensional devices and devices created thereby

• US 20040156478A1
• Filed: 12/01/2003
• Published: 08/12/2004
• Est. Priority Date: 06/05/2001
• Status: Active Grant

• Current Assignee: Rtx Corporation
• Original Assignee: Iain Fraser, James E. Atkinson, Michael P. Appleby
• Inventors: Atkinson, James E, Appleby, Michael P, Fraser, Iain
• Granted Patent: US 7,410,606 B2
• Time in Patent Office: Days
• US Class Current: 378/147
• CPC Class Codes: A61B 6/4258 for detecting non x-ray radiation, e.g. gamma radiation A61B6/037 takes precedence
• CPC Class Codes: A61B 6/502 for diagnosis of breast, i.e. mammography
• CPC Class Codes: B22D 19/00 Casting in, on, or around objects which form part of the product B22D23/04 takes precedence; alumino-thermic welding B23K23/00; coating by casting molten material on the substrate C23C6/00
• CPC Class Codes: B22D 29/00 Removing castings from moulds, not restricted to casting processes covered by a single main group; Removing cores; Handling ingots B22D13/10, B22D11/124, B22D17/00 take precedence
• CPC Class Codes: B23P 15/246 Laminated dies
• CPC Class Codes: B28B 7/20 Moulds for making shaped articles with undercut recesses, e.g. dovetails
• CPC Class Codes: B28B 7/24 Unitary mould structures with a plurality of moulding spaces , e.g. moulds divided into multiple moulding spaces by integratable partitions, mould part structures providing a number of moulding spaces in mutual co-operation assemblies of individually complete moulds B28B7/26
• CPC Class Codes: B29C 33/0088 Multi-face stack moulds
• CPC Class Codes: B29C 33/12 with incorporated means for positioning inserts, e.g. labels positioning reinforcements B29C70/541
• CPC Class Codes: B29C 33/302 Assembling a large number of mould elements to constitute one cavity
• CPC Class Codes: B29C 33/3842 Manufacturing moulds, e.g. shaping the mould surface by machining
• CPC Class Codes: B29C 33/42 characterised by the shape of the moulding surface, e.g. ribs or grooves
• CPC Class Codes: B29C 33/424 Moulding surfaces provided with means for marking or patterning for injection moulding B29C45/372
• CPC Class Codes: B29C 33/44 with means for, or specially constructed to facilitate, the removal of articles, e.g. of undercut articles
• CPC Class Codes: B29C 39/021 by casting in several steps
• CPC Class Codes: B29C 39/34 for undercut articles
• CPC Class Codes: B29C 39/36 Removing moulded articles
• CPC Class Codes: B29C 48/12 Articles with an irregular circumference when viewed in cross-section, e.g. window profiles
• CPC Class Codes: B29C 69/001 a shaping technique combined with cutting, e.g. in parts or slices combined with rearranging and joining the cut parts for reinforced material B29C70/545; B29C49/4278, B29C51/268 take precedence
• CPC Class Codes: B29K 2083/00 Use of polymers having silicon, with or without sulfur, nitrogen, oxygen, or carbon only, in the main chain, as moulding material
• CPC Class Codes: B29L 2031/756 : Microarticles, nanoarticles
• CPC Class Codes: G01T 1/20 : with scintillation detectors
• CPC Class Codes: G01T 7/00 : Details of radiation-measuring instruments
• CPC Class Codes: G03F 7/0017 : for the production of embossing, cutting or similar devices; for the production of casting means
• CPC Class Codes: G21K 1/02 : using diaphragms, collimators
• CPC Class Codes: Y10T 428/31 : Surface property or characteristic of web, sheet or block

Abstract

A process of making a casting includes the steps of designing a mold (1010), fabricating the layers (or laminations) of the mold (1020), stacking and assembling the laminations into a mold (1030), producing a casting (1060) and demolding the casting (1070). If necessary, a derived mold can be made (1040, 1050) prior to producing the casing (1060).

Claims

1. A method of forming a casting, comprising:

filling a mold having a stacked plurality of lithographically-derived micro-machined metallic foil layers with a first casting material to form a first cast product, the stacked plurality of lithographically-derived micro-machined metallic foil layers defining a protruding undercut; and

demolding the first cast product from the mold.

2. The method of claim 1, further comprising providing the mold.

3. The method of claim 1, further comprising, for each of the stacked plurality of lithographically-derived micro-machined layers, designing a feature associated with the layer.

4. The method of claim 1, further comprising designing a feature associated with all of the stacked plurality of lithographically-derived micro-machined layers of the mold.

5. The method of claim 1, further comprising micro-machining each of the stacked plurality of lithographically-derived micro-machined layers.

6. The method of claim 1, further comprising, for each of the stacked plurality of lithographically-derived micro-machined layers, micro-machining a feature associated with the layer.

7. The method of claim 1, further comprising micro-machining a feature associated with all of the stacked plurality of lithographically-derived micro-machined layers.

8. The method of claim 1, further comprising stacking the stacked plurality of lithographically-derived micro-machined layers.

9. The method of claim 1, further comprising aligning the stacked plurality of lithographically-derived micro-machined layers.

10. The method of claim 1, further comprising bonding the stacked plurality of lithographically-derived micro-machined layers.

11. The method of claim 1, further comprising clamping the stacked plurality of lithographically-derived micro-machined layers.

12. The method of claim 1, further comprising securing the stacked plurality of lithographically-derived micro-machined layers.

13. The method of claim 1, further comprising affixing the stacked plurality of lithographically-derived micro-machined layers.

14. The method of claim 1, further comprising fabricating the mold.

15. The method of claim 1, further comprising allowing the first casting material to solidify to form the first cast product.

16. The method of claim 1, further comprising surrounding the first cast product with a second casting material.

17. The method of claim 1, further comprising surrounding the first cast product with a second casting material and allowing the second casting material to solidify into a second cast product.

18. The method of claim 1, further comprising surrounding the first cast product with a second casting material and allowing the second casting material to solidify into a nonplanar second cast product.

19. The method of claim 1, further comprising forming the first cast product into a non-planar shape.

20. The method of claim 1, further comprising forming the first cast product into a non-planar shape and surrounding the formed first cast product with a second casting material and allowing the second casting material to solidify into a nonplanar second cast product.

21. The method of claim 1, further comprising surrounding the first cast product with a second casting material and demolding a second cast product formed from the second casting material.

22. The method of claim 1, wherein the first casting material comprises a flexible polymer.

23. The method of claim 1, wherein the first casting material comprises an elastomer.

24. The method of claim 1, wherein the first casting material comprises silicone rubber.

25. The method of claim 1, wherein the stacked plurality of lithographically-derived micro-machined layers define a cavity having a protruding undercut.

26. The method of claim 1, wherein the stacked plurality of lithographically-derived micro-machined layers define a plurality of cavities therein.

27. The method of claim 1, further comprising positioning an insert into a cavity defined by the stacked plurality of lithographically-derived micro-machined layers.

28. The method of claim 1, further comprising positioning an insert into a cavity defined by the stacked plurality of lithographically-derived micro-machined layers, the insert occupying only a portion of the cavity.

29. The method of claim 1, further comprising positioning an insert into a cavity defined by the stacked plurality of lithographically-derived micro-machined layers prior to said filling the mold with the first casting material.

30. The method of claim 1, further comprising positioning a lithographically-derived micro-machined insert into a cavity defined by the stacked plurality of lithographically-derived micro-machined layers prior to said filling the mold with the first casting material.

31. The method of claim 1, wherein the first cast product has an aspect ratio greater than 100:

1.

32. The method of claim 1, further comprising surrounding the first cast product with a second casting material and demolding a second cast product formed from the second casting material, the second cast product having an aspect ratio greater than 100:

1.

33. The method of claim 1, wherein a cavity defined by the stacked plurality of lithographically-derived micro-machined layers has an aspect ratio greater than 100:

1.

34. The method of claim 1, wherein the first cast product is an end product.

35. The method of claim 1, further comprising surrounding the first cast product with a second casting material and demolding a second cast product formed from the second casting material, the second cast product being an end product.

36. The method of claim 1, wherein the first cast product is attached to a substrate.

37. The method of claim 1, wherein the first cast product is a free-standing structure.

38. A method of forming a casting, comprising:

filling a mold having a stacked plurality of non-lithographically-derived micro-machined foil layers with a first casting material to form a first cast product, the stacked plurality of non-lithographically-derived micro-machined foil layers defining a protruding undercut; and

demolding the first cast product from the mold.

39. The method of claim 38, further comprising providing the mold.

40. The method of claim 38, further comprising, for each of the stacked plurality of non-lithographically-derived micro-machined layers, designing a feature associated with the layer.

41. The method of claim 38, further comprising designing a feature associated with all of the stacked plurality of non-lithographically-derived micro-machined layers of the mold.

42. The method of claim 38, further comprising micro-machining each of the stacked plurality of non-lithographically-derived micro-machined layers.

43. The method of claim 38, further comprising, for each of the stacked plurality of non-lithographically-derived micro-machined layers, micro-machining a feature associated with the layer.

44. The method of claim 38, further comprising micro-machining a feature associated with all of the stacked plurality of non-lithographically-derived micro-machined layers.

45. The method of claim 38, further comprising stacking the stacked plurality of non-lithographically-derived micro-machined layers.

46. The method of claim 38, further comprising aligning the stacked plurality of non-lithographically-derived micro-machined layers.

47. The method of claim 38, further comprising bonding the stacked plurality of non-lithographically-derived micro-machined layers.

48. The method of claim 38, further comprising clamping the stacked plurality of non-lithographically-derived micro-machined layers.

49. The method of claim 38, further comprising securing the stacked plurality of non-lithographically-derived micro-machined layers.

50. The method of claim 38, further comprising affixing the stacked plurality of non-lithographically-derived micro-machined layers.

51. The method of claim 38, further comprising fabricating the mold.

52. The method of claim 38, further comprising allowing the first casting material to solidify to form the first cast product.

53. The method of claim 38, further comprising surrounding the first cast product with a second casting material.

54. The method of claim 38, further comprising surrounding the first cast product with a second casting material and allowing the second casting material to solidify into a second cast product.

55. The method of claim 38, further comprising surrounding the first cast product with a second casting material and allowing the second casting material to solidify into a nonplanar second cast product.

56. The method of claim 38, further comprising forming the first cast product into a non-planar shape.

57. The method of claim 38, further comprising forming the first cast product into a non-planar shape and surrounding the formed first cast product with a second casting material and allowing the second casting material to solidify into a nonplanar second cast product.

58. The method of claim 38, further comprising surrounding the first cast product with a second casting material and demolding a second cast product formed from the second casting material.

59. The method of claim 38, wherein the first casting material comprises a flexible polymer.

60. The method of claim 38, wherein the first casting material comprises an elastomer.

61. The method of claim 38, wherein the first casting material comprises silicone rubber.

62. The method of claim 38, wherein the stacked plurality of non-lithographically-derived micro-machined layers define a cavity having a protruding undercut.

63. The method of claim 38, wherein the stacked plurality of non-lithographically-derived micro-machined layers define a plurality of cavities therein.

64. The method of claim 38, further comprising positioning an insert into a cavity defined by the stacked plurality of non-lithographically-derived micro-machined layers.

65. The method of claim 38, further comprising positioning an insert into a cavity defined by the stacked plurality of non-lithographically-derived micro-machined layers, the insert occupying only a portion of the cavity.

66. The method of claim 38, further comprising positioning an insert into a cavity defined by the stacked plurality of non-lithographically-derived micro-machined layers prior to said filling the mold with the first casting material.

67. The method of claim 38, further comprising positioning a non-lithographically-derived micro-machined insert into a cavity defined by the stacked plurality of non-lithographically-derived micro-machined layers prior to said filling the mold with the first casting material.

68. The method of claim 38, wherein the first cast product has an aspect ratio greater than 100:

1.

69. The method of claim 38, further comprising surrounding the first cast product with a second casting material and demolding a second cast product formed from the second casting material, the second cast product having an aspect ratio greater than 100:

1.

70. The method of claim 38, wherein a cavity defined by the stacked plurality of non-lithographically-derived micro-machined layers has an aspect ratio greater than 100:

1.

71. The method of claim 38, wherein the first cast product is an end product.

72. The method of claim 38, further comprising surrounding the first cast product with a second casting material and demolding a second cast product formed from the second casting material, the second cast product being an end product.

73. The method of claim 38, wherein the first cast product is attached to a substrate.

74. The method of claim 38, wherein the first cast product is a free-standing structure.

75. A method of forming a casting, comprising:

filling a mold having a stacked plurality of lithographically-derived micro-machined metallic foil layers with a first casting material to form a first cast product, the stacked plurality of lithographically-derived micro-machined metallic foil layers defining a protruding undercut; and

demolding the first cast product from the mold, the first cast product reflecting the protruding undercut.

76. A method of forming a casting, comprising:

filling a mold having a stacked plurality of lithographically-derived micro-machined metallic foil layers with a first casting material to form a first cast product, the stacked plurality of lithographically-derived micro-machined metallic foil layers defining a sandwiched cavity; and

demolding the first cast product from the mold, the first cast product reflecting the sandwiched cavity.

77. A method of forming a casting, comprising:

filling a mold having a stacked plurality of lithographically-derived micro-machined metallic foil layers with a first casting material to form a first cast product, the stacked plurality of lithographically-derived micro-machined metallic foil layers defining a feature having an aspect ratio greater than 20;

1; and

demolding the first cast product from the mold, the first cast product reflecting the feature.

78. A method of forming a casting, comprising:

filling a mold having a stacked plurality of lithographically-derived micro-machined layers with a first casting material to form a first cast product, the stacked plurality of lithographically-derived micro-machined layers defining a feature having an isotropic wall; and

demolding the first cast product from the mold, the first cast product reflecting the feature.

79. A method of fabricating a stack lamination mold, comprising:

for each of a plurality of metallic foil layers, lithographically micro-machining a layer feature on the layer;

assembling the plurality of layers into a stack; and

aligning the layer features to define a stack feature having an aspect ratio greater than 50;

1.

80. A method of fabricating a stack lamination mold, comprising:

for each of a plurality of metallic foil layers, lithographically micro-machining a feature on the layer;

assembling the plurality of layers into a stack; and

aligning the features to within 2 microns.

81. A method of fabricating a stack lamination mold, comprising the activities of:

for each of a plurality of metallic foil layers, lithographically defining a plurality of features on the layer;

micro-machining each of the plurality of layers, said micro-machining activity selected from laser machining, ion etching, electroplating, vapor deposition, bulk micro-machining, surface micro-machining, and conventional machining; and

assembling the plurality of layers into a stack.

82. A method of fabricating a stack lamination mold, comprising:

lithographically micro-machining a feature on a predetermined layer of a plurality of layers, said feature having at least one isotropic wall;

assembling the plurality of layers into a stack.

83. A method comprising lithographically micro-machining a feature on a predetermined layer of a plurality of layers, said feature having at least one isotropic wall.

84. A method of fabricating a stack lamination mold, comprising:

lithographically micro-machining a feature in a first layer of a plurality of layers, said first layer'"'"'s feature bordered by at least one wall having a predetermined first surface finish; and

lithographically micro-machining a feature in a second layer of the plurality of layers, said second layer'"'"'s feature bordered by at least one wall having a predetermined second surface finish, the predetermined second surface finish differing from the predetermined first surface finish.

85. A method of fabricating a stack lamination mold, comprising:

lithographically micro-machining a feature and a channel in a predetermined layer of a plurality of metallic foil layers, the channel fluidly coupling the feature to an outer edge of the predetermined layer;

assembling the plurality of layers into a stack.

86. A method of fabricating a stack lamination mold, comprising:

lithographically micro-machining each of a plurality of metallic foil layers; and

assembling the plurality of layers into a stack that defines a protruding undercut.

87. A lithographically-derived micro-machined metallic foil stack lamination mold, said mold defining a stack feature having an aspect ratio greater than 50:

1.

88. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 87, wherein said aspect ratio is greater than 75:

1.

89. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 87, wherein said aspect ratio is greater than 100:

1.

90. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 87, wherein said aspect ratio is greater than 150:

1.

91. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 87, wherein said aspect ratio is greater than 200:

1.

92. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 87, wherein said aspect ratio is greater than 250:

1.

93. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 87, wherein said aspect ratio is greater than 300:

1.

94. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 87, wherein said aspect ratio is greater than 400:

1.

95. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 87, wherein said mold is a positive replication of a predetermined end product.

96. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 87, wherein said mold is a negative replication of a predetermined end product.

97. A non-lithographically-derived micro-machined metallic foil stack lamination mold, said mold defining a protruding undercut.

98. A non-lithographically-derived micro-machined metallic foil stack lamination mold, said mold defining a stack feature having an aspect ratio greater than 50:

1.

99. A lithographically-derived micro-machined metallic foil stack lamination mold that defines a protruding undercut.

100. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 99, wherein said mold is a positive replication of a predetermined end product.

101. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 99, wherein said mold is a negative replication of a predetermined end product.

102. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 99, wherein said mold defines at least one feature having an aspect ratio of greater than 10:

1.

103. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 99, wherein said mold defines at least one feature having an aspect ratio of greater than 15:

1.

104. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 99, wherein said mold defines at least one feature having an aspect ratio of greater than 20:

1.

105. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 99, wherein said mold defines at least one feature having an aspect ratio of greater than 25:

1.

106. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 99, wherein said mold defines at least one feature having an aspect ratio of greater than 30:

1.

107. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 99, wherein said mold defines at least one feature having an aspect ratio of greater than 40:

1.

108. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 99, wherein said mold defines at least one feature having an aspect ratio of greater than 50:

1.

109. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 99, wherein said mold defines at least one feature having an aspect ratio of greater than 75:

1.

110. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 99, wherein said mold defines at least one feature having an aspect ratio of greater than 100:

1.

111. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 99, wherein said mold defines at least one feature having an aspect ratio of greater than 150:

1.

112. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 99, wherein said mold defines at least one feature having an aspect ratio of greater than 200:

1.

113. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 99, wherein said mold defines at least one feature having an aspect ratio of greater than 250:

1.

114. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 99, wherein said mold defines at least one feature having an aspect ratio of greater than 300:

1.

115. The lithographically-derived micro-machined metallic foil stack lamination mold of claim 99, wherein said mold defines at least one feature having an aspect ratio of greater than 400:

1.

116. A lithographically-derived micro-machined stack lamination mold, said mold including a layer having a feature with at least one isotropic wall.

117. A lithographically-derived micro-machined stack lamination mold, comprising:

a lithographically micro-machined feature in a first layer of a plurality of layers, said first layer'"'"'s feature bordered by at least one wall having a predetermined first surface finish; and

a lithographically micro-machined feature in a second layer of said plurality of layers, said second layer'"'"'s feature bordered by at least one wall having a predetermined second surface finish, said predetermined second surface finish differing from said predetermined first surface finish.

118. A lithographically-derived micro-machined metallic foil stack lamination mold, said mold defining a sub-cavity.

119. A lithographically-derived micro-machined metallic foil stack lamination mold, said mold defining a sub-cavity in a layer of said mold, said sub-cavity in fluid communication with an outer edge of said layer.

120. A mold having a stacked plurality of lithographically-derived micro-machined metallic foil layers that define at least one feature having an aspect ratio of greater than 10:

1.

121. A metallic foil stack lamination mold that defines a protruding undercut.

122. A metallic foil stack lamination mold that defines a cavity having a protruding undercut.

123. A stack lamination mold comprising a plurality of lithographically-derived micro-machined ceramic layers.

124. A stack lamination mold comprising a plurality of lithographically-derived micro-machined metallic foil layers.

125. A mold derived from a metallic foil stack lamination mold, said derived mold defining a cavity therein and a feature having an aspect ratio greater than 10:

1.

126. A mold derived from a metallic foil stack lamination mold, said derived mold defining a protruding undercut.

127. A mold derived from a metallic foil stack lamination mold, said derived mold defining a cavity having a protruding undercut.

128. A mold derived from a stack lamination mold having a plurality of layers comprised of metallic foil material.

129. A mold derived from a stack lamination mold having a plurality of layers comprised of ceramic material.

130. A mold derived from a metallic foil stack lamination mold, said derived mold comprised of polymeric material.

131. A mold derived from a metallic foil stack lamination mold, said derived mold a positive replication of a predetermined end product.

132. A mold derived from a metallic foil stack lamination mold, said derived mold a negative replication of a predetermined end product.

133. A cast collimator derived from a metallic foil stack lamination mold, said collimator having a wall thickness of less than 100 microns.

134. A cast collimator derived from a metallic foil stack lamination mold, said collimator having a plurality of walls, at least one wall from said plurality of walls having a thickness of less than 100 microns.

135. A cast collimator derived from a metallic foil stack lamination mold, said collimator having an aspect ratio of approximately 70 to approximately 300.

136. A cast collimator derived from a metallic foil stack lamination mold, said collimator having a plurality of walls, at least one wall from said plurality of walls having an aspect ratio of approximately 70 to approximately 300.

137. A cast collimator derived from a lithographically-derived micro-machined metallic foil stack lamination mold, said collimator having a plurality of non-redundant cells.

138. A cast collimator derived from a lithographically-derived micro-machined metallic foil stack lamination mold, said collimator having a plurality of cells, each of said cells from said plurality of cells having a width of 1 millimeter or less.

139. A cast collimator derived from a metallic foil stack lamination mold, said collimator having a non-planar side.

140. A cast collimator derived from a metallic foil stack lamination mold, said collimator comprising a first side and a second side, wherein one of said sides is non-planar.

141. A cast collimator derived from a metallic foil stack lamination mold, comprising a first side and a second side, wherein both of said sides are non-planar.

142. A cast collimator derived from a lithographically-derived micro-machined stack lamination mold, said collimator cast from a casting material mixed with plurality of dense particles.

143. The cast collimator of claim 142, wherein said collimator includes a cross grid.

144. The cast collimator of claim 142, wherein said collimator is a linear grid.

145. The cast collimator of claim 142, wherein said collimator is a scatter reduction grid.

146. The cast collimator of claim 142, wherein said collimator is focused.

147. The cast collimator of claim 142, wherein said collimator is unfocused.

148. A cast collimator derived from a stack lamination mold, comprising a first side and a second side, wherein one of said sides is non-planar and said collimator has a uniform thickness measured between said first side and said second side.

149. A cast collimator derived from a metallic foil stack lamination mold, comprising a first side and a second side, and defining a plurality of cells that are focally aligned to a point at a predetermined distance.

150. A cast collimator derived from a metallic foil stack lamination mold, said collimator defining a plurality of cells each having a width less than 500 microns and a height, a ratio of said height to said width greater than 4:

1.

164. The cast collimator of claim 150, wherein said collimator is comprised of a polymeric material combined with tungsten particles.

165. The cast collimator of claim 150, wherein said collimator is comprised of ceramic material.

166. The cast collimator of claim 150, wherein said collimator is comprised of lead.

167. The cast collimator of claim 150, wherein said collimator is comprised of a lead alloy.

168. The cast collimator of claim 150, wherein said collimator defines a plurality of open passages that are focally aligned to a predetermined distance.

169. The cast collimator of claim 150, wherein said collimator is comprised of polymeric material.

170. The cast collimator of claim 150, wherein said collimator is comprised of polymeric material combined with a plurality of dense particles.

171. The cast collimator of claim 150, wherein said collimator is comprised of a plurality of dense particles.

172. The cast collimator of claim 150, wherein said collimator is comprised of a plurality of dense particles selected from gold, tantalum, and tungsten.

173. The cast collimator of claim 150, wherein said collimator is comprised of lead combined with a plurality of dense particles.

174. The cast collimator of claim 150, wherein said collimator is comprised of a lead alloy combined with a plurality of dense particles.

175. The cast collimator of claim 150, further comprising radiation detector elements attached to said collimator.

176. The cast collimator of claim 150, further comprising a plurality of radiation detector elements focally aligned by openings defined by said collimator to a radiation source at a predetermined distance.

177. The cast collimator of claim 150, further comprising a plurality of radiation detector elements aligned with openings defined by said collimator.

151. A cast collimator derived from a metallic foil stack lamination mold, said collimator defining a plurality of cells each having a width less than 500 microns and a height, a ratio of said height to said width greater than 10:

1.

152. A cast collimator derived from a metallic foil stack lamination mold, said collimator defining a plurality of cells each having a width less than 500 microns and a height, a ratio of said height to said width greater than 20:

1.

153. A cast collimator derived from a metallic foil stack lamination mold, said collimator defining a plurality of cells each having a width less than 500 microns and a height, a ratio of said height to said width greater than 40:

1.

154. A cast collimator derived from a metallic foil stack lamination mold, said collimator defining a plurality of cells each having a width less than 400 microns and a height, a ratio of said height to said width greater than 4:

1.

155. A cast collimator derived from a metallic foil stack lamination mold, said collimator defining a plurality of cells each having a width less than 400 microns and a height, a ratio of said height to said width greater than 8:

1.

156. A cast collimator derived from a metallic foil stack lamination mold, said collimator defining a plurality of cells each having a width less than 400 microns and a height, a ratio of said height to said width greater than 16:

1.

157. A cast collimator derived from a metallic foil stack lamination mold, said collimator defining a plurality of cells each having a width less than 400 microns and a height, a ratio of said height to said width greater than 32:

1.

158. A cast collimator derived from a metallic foil stack lamination mold, said collimator defining a plurality of cells each having a width less than 400 microns and a height, a ratio of said height to said width greater than 40:

1.

159. A cast collimator derived from a metallic foil stack lamination mold, said collimator defining a plurality of cells each having a width less than 200 microns and a height, a ratio of said height to said width greater than 4:

1.

160. A cast collimator derived from a metallic foil stack lamination mold, said collimator defining a plurality of cells each having a width less than 200 microns and a height, a ratio of said height to said width greater than 8:

1.

161. A cast collimator derived from a metallic foil stack lamination mold, said collimator defining a plurality of cells each having a width less than 200 microns and a height, a ratio of said height to said width greater than 16:

1.

162. A cast collimator derived from a metallic foil stack lamination mold, said collimator defining a plurality of cells each having a width less than 200 microns and a height, a ratio of said height to said width greater than 32:

1.

163. A cast collimator derived from a metallic foil stack lamination mold, said collimator defining a plurality of cells each having a width less than 200 microns and a height, a ratio of said height to said width greater than 40:

1.

178. A method of forming a plurality of castings, comprising:

repetitively;

filling a mold having a stacked plurality of lithographically-derived micro-machined foil layers with a first casting material to form a first cast product, the stacked plurality of lithographically-derived micro-machined foil layers defining a protruding undercut; and

demolding the first cast product from the mold.

179. A method of forming a casting, comprising:

filling a mold having a stacked plurality of lithographically-derived micro-machined layers with a first casting material to form a first cast product, the stacked plurality of lithographically-derived micro-machined layers defining a protruding undercut; and

demolding the first cast product from the mold, such that the mold is not substantially damaged.

180. A method of forming a casting, comprising:

filling a mold having a stacked plurality of non-lithographically-derived micro-machined layers with a first casting material to form a first cast product, the stacked plurality of non-lithographically-derived micro-machined layers defining a protruding undercut; and

demolding the first cast product from the mold such that the mold is not substantially damaged.

181. A method of forming a casting, comprising:

filling a mold having a stacked plurality of lithographically-derived micro-machined layers with a first casting material to form a first cast product, the stacked plurality of lithographically-derived micro-machined layers defining a protruding undercut; and

demolding the first cast product from the mold such that the mold is not substantially damaged, the first cast product reflecting the protruding undercut.

182. A method of forming a casting, comprising:

filling a reusable mold having a stacked plurality of lithographically-derived micro-machined layers with a first casting material to form a first cast product, the stacked plurality of lithographically-derived micro-machined layers defining a protruding undercut; and

demolding the first cast product from the reusable mold.

183. A non-laminated cast collimator having a wall thickness of less than 100 microns.

184. A non-laminated cast collimator having a non-planar side.

185. A derived mold comprising a stack of layers derived from a metallic foil stack lamination mold.

186. A derived mold comprising a stack of ceramic layers derived from a metallic foil stack lamination mold.

187. A derived mold comprising a stack of polymeric layers derived from a metallic foil stack lamination mold.

188. A non-laminated cast collimator derived from a metallic foil stack lamination mold.

189. The non-laminated cast collimator of claim 188, said collimator comprising a ceramic.

190. The non-laminated cast collimator of claim 188, said collimator comprising a polymer.