Tool to pick up microparts

Abstract

This is a tool for use in picking up small, or even microscopic, objects and placing them where they are wanted. Applications include the assembly of micromachines, and scientific collection of particle specimens. The various embodiments use one or more of the following quantities to control the pick-up force of the tool: electrostatic potential, capillary (surface tension) force using one or more liquids, and heat.

1 . an electrostatic pickup tool for picking up parts weighing less than 0.0001 newtons, said electrostatic pick up tool having at least one finger such that: 
 a. said finger having a distal end and a proximal end    b. the material of the finger is electrically conductive, and the surface of the distal end is covered with an electrically nonconducting layer so that the part to be picked up is contacted only by nonconductive material    c. the material of the finger is mechanically elastic, and the geometry of the finger renders it mechanically compliant, so that the contact forces that can be applied to the part to be pick up fall within a predetermined range from 0 newtons to less than 0.01 newtons    d. the proximal end of the finger is attached to a handle which provides mechanical connection to positioning stages, and electrical connection to a voltage source.    
   
   
       2 . the electrostatic pick up tool of  claim 1  in which the material of the finger is single crystal silicon, and the nonconductive layer at the distal end is one of the following: silicon dioxide, silicon nitride, an organic polymer (such as parylene)  
   
   
       3 . the electrostatic pick up tool of  claim 2  having 2 fingers  
   
   
       4 . the electrostatic pick up tool of  claim 2  having three noncolinear fingers  
   
   
       5 . the electrostatic pick up tool of  claim 2  having more than three noncolinear noncoplanar fingers  
   
   
       6 . the electrostatic pick up tool of  claim 1  having a v shaped distal end to contact a cylindrical object  
   
   
       7 . the electrostatic pick up tool of  claim 3  having a v shaped distal end at each finger aligned to contact a cylindrical object  
   
   
       8 . a capillary pickup tool for picking up parts weighing less than 0.0001 newtons, said capillary pick up tool having at least one finger such that: 
 a. said finger having a distal end and a proximal end    b. the surface of the distal end is to be coated with a liquid layer so that the part to be picked up is contacted by liquid    c. the material of the finger is mechanically elastic, and the geometry of the finger renders it compliant, so that the contact forces that can be applied to the part fall within a predetermined range from 0 newtons to less than 0.01 newtons    d. the proximal end of the finger is attached to a handle which provides mechanical connection to positioning stages    
   
   
       9 . the capillary pick up tool of  claim 8  in which the material of the finger is single crystal silicon, and the liquid is one of, or a combination of: hexadecane, ethylene glycol, water, hydrocarbon oil,  
   
   
       10 . the capillary pick up tool of  claim 9  having 2 fingers  
   
   
       11 . the capillary pick up tool of  claim 9  having three noncolinear fingers  
   
   
       12 . the capillary pick up tool of  claim 9  having more than three noncolinear noncoplanar fingers  
   
   
       13 . the capillary pick up tool of  claim 8  having a v shaped distal end to contact a cylindrical object  
   
   
       14 . the capillary pick up tool of  claim 10  having a v shaped distal end at each finger aligned to contact a cylindrical object