Microscale and Millimeter Scale Devices Including Threaded Elements, Methods for Designing, and Methods for Making

Abstract

Embodiments of the invention provide threaded elements alone, in mating pairs, or in conjunction with other elements. Embodiments of the invention also provide for design and fabrication of such threaded elements without violating minimum feature size design rules or causing other interference issues that may result from the fabrication of such thread elements using a multi-layer multi-material electrochemical fabrication process.

We claim: 
     
         1 . A micro-scale or millimeter scale male threaded element, comprising
 (a) an axial dimension and a radial dimension that extends perpendicular to the axial dimension;   (b) at least one outward facing thread comprising radial extensions and radial depressions that define a spiral turn of at least 90° around and along the axial dimension;   wherein the threaded element has a stair stepped configuration with the stair steps defining a plurality of planes spaced from adjacent planes by a layer thickness,   wherein there exists a maximum and minimum radial extension for the thread for each axial position; and   wherein selected portions of the radial features of the threaded element meet a criteria selected from the group consisting of: (1) the selected portions are located along the maximum radial dimension and are flattened relative to non-selected portions of the maximum radial dimension such that the selected portions have longer axial lengths relative to the axial length of the non-selected portions, (2) the selected portions are located along the maximum radial dimension and are flattened relative to non-selected portions of the maximum radial dimension such that the selected portions have longer axial lengths relative to the axial length of the non-selected portions wherein the longer axial length is at least as large as the layer thickness, (3) the selected portions are located along the maximum radial dimension and are flattened relative to non-selected portions of the maximum radial dimension such that the selected portions have longer axial lengths relative to the axial length of the non-selected portions wherein the longer axial length is at least as large as a minimum feature size, (4) the selected portions are located along the minimum radial dimension along and are flattened relative to non-selected portions of the minimum radial dimension such that the selected portions have longer axial lengths relative to the axial length of the non-selected portions, (5) the selected portions are located along the minimum radial dimension along and are flattened relative to non-selected portions of the minimum radial dimension such that the selected portions have longer axial lengths relative to the axial length of the non-selected portions wherein the longer axial length is at least as large as the layer thickness, and (6) the selected portions are located along the minimum radial dimension along and are flattened relative to non-selected portions of the minimum radial dimension such that the selected portions have longer axial lengths relative to the axial length of the non-selected portions wherein the longer axial length is at least as large as a minimum feature size.   
     
     
         2 . The element of  claim 1  wherein the spiral turn is continuous. 
     
     
         3 . The element of  claim 1  wherein the spiral turn is discontinuous. 
     
     
         4 . The element of  claim 1  wherein the spiral turn extends at least 180°. 
     
     
         5 . The element of  claim 1  wherein the spiral turn extends at least 360°. 
     
     
         6 . The element of  claim 1  wherein the spiral turn extends at least 720°. 
     
     
         7 . The element of  claim 1  wherein the male threaded element is configured to thread into a counterpart female threaded element. 
     
     
         8 . A micro-scale or millimeter scale female threaded element, comprising:
 (a) an axial dimension and a radial dimension that extends perpendicular to the axial dimension;   (b) at least one inward facing thread comprising radial extensions defining openings of smaller radius and radial depressions defining openings of larger radius, wherein the thread provides a spiral turn of at least 90° around and along the axial dimension;   wherein the thread has a stair stepped configuration with the stair steps defining a plurality of planes spaced from adjacent planes by a layer thickness,   wherein there exists a maximum and minimum radial extension for the thread for each axial position; and   wherein selected portions of the radial features of the threaded element meet a criteria selected from the group consisting of: (1) the selected portions are located along the maximum radial dimension and are flattened relative to non-selected portions of the maximum radial dimension such that the selected portions have longer axial lengths relative to the axial length of the non-selected portions, (2) the selected portions are located along the maximum radial dimension and are flattened relative to non-selected portions of the maximum radial dimension such that the selected portions have longer axial lengths relative to the axial length of the non-selected portions wherein the longer axial length is at least as large as the layer thickness, (3) the selected portions are located along the maximum radial dimension and are flattened relative to non-selected portions of the maximum radial dimension such that the selected portions have longer axial lengths relative to the axial length of the non-selected portions wherein the longer axial length is at least as large as a minimum feature size, (4) the selected portions are located along the minimum radial dimension along and are flattened relative to non-selected portions of the minimum radial dimension such that the selected portions have longer axial lengths relative to the axial length of the non-selected portions, (5) the selected portions are located along the minimum radial dimension along and are flattened relative to non-selected portions of the minimum radial dimension such that the selected portions have longer axial lengths relative to the axial length of the non-selected portions wherein the longer axial length is at least as large as the layer thickness, and (6) the selected portions are located along the minimum radial dimension along and are flattened relative to non-selected portions of the minimum radial dimension such that the selected portions have longer axial lengths relative to the axial length of the non-selected portions wherein the longer axial length is at least as large as a minimum feature size.   
     
     
         9 . The element of  claim 8  wherein the spiral turn is continuous. 
     
     
         10 . The element of  claim 8  wherein the spiral turn is discontinuous. 
     
     
         11 . The element of  claim 8  wherein the spiral turn extends at least 180°. 
     
     
         12 . The element of  claim 8  wherein the spiral turn extends at least 360°. 
     
     
         13 . The element of  claim 8  wherein the spiral turn extends at least 720°. 
     
     
         14 . The element of  claim 8  wherein the female threaded element is configured to receive a counterpart male threaded element. 
     
     
         15 . A micro-scale or millimeter scale device, comprising:
 (a) a male threaded element, comprising:
 i. an axial dimension and a radial dimension that extends perpendicular to the axial dimension; 
 ii. at least one outward facing thread comprising radial extensions and radial depressions that define a spiral turn of at least 90° around and along the axial dimension; 
 wherein the male threaded element has a stair stepped configuration with the stair steps defining a plurality of planes spaced from adjacent planes by a layer thickness, and 
   (b) a female threaded element, comprising:
 i. an axial dimension and a radial dimension that extends perpendicular to the axial dimension; 
 ii. at least one inward facing female thread comprising radial extensions defining openings of smaller radius and radial depressions defining openings of larger radius, wherein the thread provides a spiral turn of at least 90° around and along the axial dimension; 
 wherein the female threaded element has a stair stepped configuration with the stair steps defining a plurality of planes spaced from adjacent planes by a layer thickness, 
   wherein the male threaded element is configured to thread into the female threaded element.