Combination horizontal and vertical thermal actuator

Abstract

A micrometer sized, single-stage, horizontal and vertical thermal actuator capable of repeatable and rapid movement of a micrometer-sized optical device off the surface of a substrate. The horizontal and vertical thermal actuator is constructed on a surface of a substrate. At least one hot arm has a first end anchored to the surface and a free end located above the surface. A cold arm has a first end anchored to the surface and a free end. The cold arm is located above and laterally offset from the hot arm relative to the surface. The cold arm is adapted to provide controlled bending near the first end thereof. A member mechanically and electrically couples the free ends of the hot and cold arms such that the actuator exhibits horizontal and vertical displacement when current is applied to at least the hot arm.

What is claimed is:  
     
         1 . A horizontal and vertical thermal actuator constructed on a surface of a substrate consisting essentially of: 
 one hot arm having a first end anchored to the surface and a free end located above the surface;    a cold arm having a first end anchored to the surface and a free end, the cold arm being located above and laterally offset from the hot arm relative to the surface; and    a member mechanically and electrically coupling the free ends of the hot and cold arms such that the actuator exhibits vertical displacement and horizontal displacement when current is applied to at least the hot arm.    
     
     
         2 . The apparatus of  claim 1  having a flexure formed in the cold arm near the first end thereof adapted to provide controlled bending.  
     
     
         3 . The apparatus of  claim 2  wherein the flexure comprises at least one of a recess, depression, cut-out, hole, location of narrowed, thinned or weakened material, alternate material or other structural features or material change that decreases resistance to bending in that location.  
     
     
         4 . The apparatus of  claim 1  further consisting essentially of a grounding tab electrically coupling the hot arm to the substrate.  
     
     
         5 . The apparatus of  claim 1  wherein the cold arm is electrically isolated from the hot arm.  
     
     
         6 . The apparatus of  claim 1  wherein the hot arm and the cold arm comprise a circuit through which electric current is passed.  
     
     
         7 . The apparatus of  claim 1  further consisting essentially of a reinforcing member formed in the cold arm.  
     
     
         8 . The apparatus of  claim 7  wherein the reinforcing member is integrally formed in the cold arm.  
     
     
         9 . The apparatus of  claim 1  comprising a metal layer extending along the cold arm.  
     
     
         10 . The apparatus of  claim 1  comprising a plurality of horizontal and vertical thermal actuators on the substrate.  
     
     
         11 . The apparatus of  claim 1  comprising at least one optical device mechanically coupled to the horizontal and vertical thermal actuator.  
     
     
         12 . The apparatus of  claim 11  wherein the optical device comprises one of a reflector, a lens, a polarizer, a wave guide, a shutter, or an occluding structure.  
     
     
         13 . The apparatus of  claim 11  comprising an optical communication system including at least one optical device.  
     
     
         14 . A horizontal and vertical thermal actuator constructed on a surface of a substrate comprising: 
 at least two hot arms, each having a first end anchored to the surface and a free end located above the surface;    a cold arm having a first end anchored to the surface and a free end and a first major side and a second major side, the cold arm being located above and laterally offset from the at least two hot arms relative to the surface and the at least two hot arms are laterally offset from the same side of the cold arm;    electrical contacts electrically coupled to the first ends of the at least two hot arms; and    a member mechanically and electrically coupling the free ends of the hot and cold arms.    
     
     
         15 . The apparatus of  claim 14  comprising a flexure formed in the cold arm near the first end thereof adapted to provide controlled bending.  
     
     
         16 . The apparatus of  claim 15  wherein the flexure comprises at least one of a recess, depression, cut-out, hole, location of narrowed, thinned or weakened material, alternate material or other structural features or material change that decreases resistance to bending in that location.  
     
     
         17 . The apparatus of  claim 14  comprising a grounding tab electrically coupling the hot arms to the substrate.  
     
     
         18 . The apparatus of  claim 14  wherein the cold arm is electrically isolated from the hot arms.  
     
     
         19 . The apparatus of  claim 14  wherein at least one hot arm and the cold arm comprise a circuit through which electric current is passed.  
     
     
         20 . The apparatus of  claim 14  comprising a reinforcing member formed in the cold arm.  
     
     
         21 . The apparatus of  claim 20  wherein the reinforcing member is integrally formed in the cold arm.  
     
     
         22 . The apparatus of  claim 14  comprising a metal layer extending along the cold arm.  
     
     
         23 . The apparatus of  claim 14  further comprising at least one hot arm laterally offset from the side of the cold arm opposite the side laterally offset from the at least two hot arms.