Wide-Angle Variable Focal Length Lens System

Abstract

A variable focal length microlens system having a base section with a fluid chamber and a fluid pressurization mechanism. A flexible, substantially transparent polymer lens section is fixed above the fluid chamber and the lens section has a curvature providing an initial focal point when in an unstrained state. The fluid chamber is substantially sealed and the fluid pressurization mechanism includes a flexible wall in the base section. The flexible wall may be displaced by magnetic activation, PZT activation of another activating mechanism.

1 . A variable focal length microlens apparatus comprising:
 a. a base section having a fluid chamber and a fluid pressurization mechanism; and   b. a flexible, substantially transparent polymer lens section fixed above said fluid chamber, said lens section having a curvature providing an initial focal point when in an unstrained state.   
   
   
       2 . The variable focal length microlens apparatus of  claim 1 , wherein said lens section has a contact angle of at least ten degrees in an unstrained state. 
   
   
       3 . The variable focal length microlens apparatus of  claim 1 , wherein said base section is formed of a polymer and said base section and lens section are joined to a silicon intermediate substrate. 
   
   
       4 . The variable focal length microlens apparatus of  claim 3 , wherein said lens section is formed substantially of a PDMS material. 
   
   
       5 . The variable focal length microlens apparatus of  claim 1 , wherein said convex lens surface has a base diameter of between about 100 um and 3000 um. 
   
   
       6 . The variable focal length microlens apparatus of  claim 5 , wherein convex lens surface has a height of between about 15 um and 200 um in said unstrained state. 
   
   
       7 . The variable focal length microlens apparatus of  claim 1 , wherein said fluid pressurization mechanism comprises a fluid channel connecting said fluid chamber to an exterior of said base section. 
   
   
       8 . The variable focal length microlens apparatus of  claim 7 , wherein said fluid channel is connected to a fluid pump exterior to said base section. 
   
   
       9 . The variable focal length microlens apparatus of  claim 1 , wherein said fluid chamber is substantially sealed and said fluid pressurization mechanism comprises said base section having a flexible wall. 
   
   
       10 . The variable focal length microlens apparatus of  claim 9 , wherein said flexible wall is displaced by a magnetic activation mechanism in order to increase the pressure of a fluid within said fluid chamber. 
   
   
       11 . The variable focal length microlens apparatus of  claim 10 , wherein said magnetic activation mechanism comprises said flexible wall having a magnetic material incorporated therein or affixed thereto and said base section includes a magnet for urging displacement of said magnetic material. 
   
   
       12 . The variable focal length microlens apparatus of  claim 11 , wherein said magnet is an electromagnet. 
   
   
       13 . The variable focal length microlens apparatus of  claim 9 , wherein said flexible wall is displaced by a PZT material acting thereon. 
   
   
       14 . The variable focal length microlens apparatus of  claim 13 , wherein said PZT material is attached to said flexible wall. 
   
   
       15 . The variable focal length microlens apparatus of  claim 1 , wherein said apparatus has a focal length range of between about 1.5 mm and 16 mm. 
   
   
       16 . The variable focal length microlens apparatus of  claim 1 , wherein said fluid chamber is substantially sealed and said fluid pressurization mechanism comprises a thermo-expansive liquid and a heating element positioned in contact with said thermo-expansive liquid. 
   
   
       17 . The variable focal length microlens apparatus of  claim 16 , wherein said liquid has a thermal expansion coefficient of between about 0.0002 and 0.002° C. −1 . 
   
   
       18 . The variable focal length microlens apparatus of  claim 16 , wherein a temperature sensor is positioned in contact with said liquid. 
   
   
       19 . The variable focal length microlens apparatus of  claim 17 , wherein said temperature sensor comprises a conductive metal trace applied to a bottom wall of said fluid chamber. 
   
   
       20 . The variable focal length microlens apparatus of  claim 16 , wherein said heating element is a metal strip applied to a bottom wall of said fluid chamber. 
   
   
       21 - 24 . (canceled)