Electrically controlled tiltable microstructures

Abstract

A support structure extends upwards from a substrate and supports a tiltable platform, the upper surface of which can be a mirror, by means of spaced flexible couplings that enable the platform to tilt relative to the support structure. Respective electrodes associated with the substrate and platform control the platform tilt in response to applied signals. The platform electrodes are preferably spaced below and tilt with the platform, with the platform extending laterally from the support structure further than the platform electrodes. The platform is preferably bulk micromachined, and the support structure surface micromachined.

1 . An electrically controlled microstructure, comprising: 
 a tiltable platform,    a substrate,    a support structure extending upward from said substrate,    a plurality of spaced flexible couplings supporting said platform with respect to said support structure and enabling the platform to tilt relative to the support structure, and    respective electrodes associated with said substrate and with said platform controlling the platform tilt in response to applied electrical signals.    
     
     
         2 . The microstructure of  claim 1 , wherein said couplings comprising flexible beams.  
     
     
         3 . The microstructure of  claim 2 , wherein said electrodes associated with said platform are coupled to respective flexible beams on opposite sides of said support structure by respective torsion arms.  
     
     
         4 . The microstructure of  claim 3 , said flexible beams and torsion arms enabling 2-axis tip/tilt motions for said platform.  
     
     
         5 . The microstructure of  claim 2 , wherein said platform and mounting structure extend laterally beyond opposite sides of said support structure.  
     
     
         6 . The microstructure of  claim 5 , said mounting structure comprising a pair of said platform electrodes, said platform electrodes aligned with corresponding substrate electrodes, and said platforms spaced above said platform electrodes.  
     
     
         7 . The microstructure of  claim 6 , wherein said platform extends laterally from said support structure further than said platform electrodes.  
     
     
         8 . The microstructure of  claim 1 , said electrodes having an interdigiated comb structure.  
     
     
         9 . The microstructure of  claim 1 , wherein said electrodes are coupled to said support structure and to said platform to produce a piston movement of the platform in response to the application of common electrical signals between said electrodes associated with said substrate, and said electrodes associated with said platform.  
     
     
         10 . The microstructure of  claim 1 , wherein said platform comprises a bulk micromachined structure, and said support structure comprises a surface micromachined structure.  
     
     
         11 . The microstructure of  claim 1 , said platform comprising silicon.  
     
     
         12 . The microstructure of  claim 1 , said platform comprising a mirror.  
     
     
         13 . The microstructure of  claim 12 , further comprising an operating system, with said mirror performing a light directing function within said operating system.  
     
     
         14 . The microstructure of  claim 13 , said operating system comprising an optical cross-coupler, a projector, an optical alternator or an atmospheric compensator.  
     
     
         15 . The microstructure of  claim 1 , further comprising a drive circuit for said electrodes, electrical connections to said electrodes which extend to the underside of said substrate, and electromechanical connectors on the underside of said substrate between said drive circuit and said electrical connections.  
     
     
         16 . An electrically controlled microstructure, comprising: 
 a substrate,    a support structure extending upward from the substrate,    tilt electrodes extending laterally out from opposite sides of said support structure and coupled to said support structure to tilt relative to said support structure and substrate,    lower electrodes carried by said substrate spaced from and in alignment with respective ones of said tilt electrodes, and    a platform carried above and tilting with said tilt electrodes, said platform extending laterally out beyond and spaced above said tilt electrodes so that it has a greater tilt angle range than if it were at the level of said tilt electrodes.    
     
     
         17 . The microstructure of  claim 16 , wherein said tilt electrodes are coupled to said support structure by flexible beams which flex to enable tilting of said tilt electrodes.  
     
     
         18 . The microstructure of  claim 17 , wherein said tilt electrodes are coupled to respective flexible beams by respective torsion arms.  
     
     
         19 . The microstructure of  claim 16 , wherein said platform comprises a bulk micromachined structure, and said support structure comprises a surface micromachined structure.  
     
     
         20 . The microstructure of  claim 16 , said platform comprising silicon.  
     
     
         21 . The microstructure of  claim 16 , said platform comprising a mirror.  
     
     
         22 . The microstructure of  claim 21 , further comprising an operating system, with said mirror performing a light directing function within said operating system.  
     
     
         23 . The microstructure of  claim 22 , said operating system comprising an optical cross-coupler, a projector, an optical alternator or an atmospheric compensator.  
     
     
         24 . The microstructure of  claim 16 , further comprising a drive circuit for said electrodes, electrical connections to said electrodes which extend to the underside of said substrate, and electromechanical connectors on the underside of said substrate between said drive circuit and said electrical connections.  
     
     
         25 . The microstructure of  claim 24 , wherein said electrical connectors comprise indium, solder or Au-alloy conductive adhesives.  
     
     
         26 . A microstructure, comprising: 
 a substrate,    a surface micromachined support structure extending upward from said substrate, and    a bulk micromachined mirror carried by said support structure to tilt relative to said substrate.    
     
     
         27 . The microstructure of  claim 26 , further comprising tilt electrodes interfacing between said support structure and said mirror, said tilt electrodes being tiltable with respect to said support structure and substrate, said mirror carried above and tilting with said tilt electrodes, and substrate electrodes carried by said substrate in alignment with and spaced from said tilt electrodes.  
     
     
         28 . The microstructure of  claim 27 , said mirror extending laterally out beyond said tilt electrodes so that it has a greater tilt angle range than if it were at the level of said tilt electrodes.  
     
     
         29 . The microstructure of  claim 26 , further comprising an operating system, with said mirror performing a light directing function within said operating system.  
     
     
         30 . The microstructure of  claim 29 , said operating system comprising an optical cross-coupler, a projector, an optical alternator or an atmospheric compensator.  
     
     
         31 . The microstructure of  claim 9 , further comprising a drive circuit for said electrodes, electrical connections to said electrodes which extend to the underside of said substrate, and electromechanical connectors on the underside of said substrate between said drive circuit and said electrical connections.