Microfabricated tools for manipulation of small samples

Abstract

Microfabricated tools useful for manipulating small, delicate samples are formed from thin plastic films. The films have a small thickness (preferably 5 to 50 micrometers and typically 10 micrometers) and small lateral dimensions (preferably 2 mm or less and typically 0.1 to 1 mm) so that they are reasonably flexible, but are preferably curved by being wrapped around a cylindrical or flat post to give them some rigidity. The softness and thinness of the plastic reduce risk of sample damage during incidental contact with the tool. Its thinness makes it optically and X-ray transparent, so that the samples can be clearly visualized during manipulations and so that the tools can be used to collect X-ray data from samples. As an option, an X-ray sensitive phosphor is incorporated in the film at low concentration. This allows the X-ray beam to be visually located on the mount or tool. The plastic can also be treated to obtain a desired hydrophobicity or hydrophilicity, mechanically embossed or abraded, or coated with films (for example, of polyethylene glycol via pegylation procedures or of PDMS) that promote or inhibit sample adhesion.

1 . A tool for working with small biological and other samples comprising: 
 a thin flexible plastic film having a base end and a tip end for engaging a sample, said film having a thickness of between 5 and 50 micrometers; and    a measuring device disposed adjacent said tip end for measuring a parameter of a sample.    
   
   
       2 . The tool of  claim 1 , wherein said measuring device comprises a ruler for measuring dimensions of a sample.  
   
   
       3 . The tool of  claim 1 , wherein said measuring device comprises a protractor for measuring angles of a sample.  
   
   
       4 . The tool of  claim 1 , wherein said measuring device comprise a temperature measuring device.  
   
   
       5 . The tool of  claim 4 , wherein said temperature measuring device is selected from the group comprising a thermocouple and a thermistor.  
   
   
       6 . The tool of  claim 1 , wherein a curvature is imparted to said film to increase its rigidity, and said base end is mounted to a holder which maintains said curvature.  
   
   
       7 . The tool of  claim 1 , wherein said film is selected to be flexible enough to bend easily and give during sample contact, thereby minimizing the chance of sample damage, and to bend easily and elastically upon contact with surfaces confining the sample, enabling said tip end to scoop up a sample.  
   
   
       8 . The tool of  claim 1 , wherein said film is selected to be optically and X-ray transparent, so that the tool can be used to collect X-ray data from samples attached to them, or to hold samples during examination in an optical microscope.  
   
   
       9 . The tool of  claim 8 , wherein an X-ray sensitive phosphor is incorporated in the film at concentration sufficient to allow an X-ray beam to be visually located on the tool.  
   
   
       10 . The tool of  claim 1 , wherein said plastic film is treated to obtain a desired hydrophobicity or hydrophilicity, or coated with a film that promotes or inhibits sample adhesion.  
   
   
       11 . A tool for working with small biological and other samples comprising: 
 a thin flexible plastic film having a base end and a tip end for engaging a sample, said film having a thickness of between 5 and 50 micrometers; and    an apertured mesh disposed at said tip end for supporting a sample and allowing excess fluid to drain away form said tip end.    
   
   
       12 . The tool of  claim 11 , wherein said apertures in said mesh are between 5 and 100 micrometers in diameter.  
   
   
       13 . The tool of  claim 11 , wherein said tip end is rounded to aid in scooping a sample onto said mesh.  
   
   
       14 . The tool of  claim 11 , wherein a curvature is imparted to said film to increase its rigidity, and said base end is mounted to a holder which maintains said curvature.  
   
   
       15 . The tool of  claim 11 , wherein said film is selected to be flexible enough to bend easily and give during sample contact, thereby minimizing the chance of sample damage, and to bend easily and elastically upon contact with surfaces confining the sample, enabling said tip end to scoop up a sample.  
   
   
       16 . A tool for working with small biological and other samples comprising: 
 a thin flexible plastic film having a base end and a tip end for engaging a sample, said film having a thickness of between 5 and 50 micrometers; and    an aperture in said tip end having a sample engaging structure disposed therein for gripping a sample.    
   
   
       17 . The tool of  claim 16 , wherein said sample engaging structure comprises a plurality of flexible fingers which extend into said aperture and bend upward as said aperture in said tip end is pushed down over a sample.  
   
   
       18 . The tool of  claim 17 , wherein each of said fingers is between 10 and 50 micrometers wide.  
   
   
       19 . The tool of  claim 17 , wherein said fingers are of at least two different lengths.  
   
   
       20 . The tool of  claim 17 , wherein said aperture splits said tip end into first and second opposed paddles and said fingers extend form each of said paddles toward one another.