Mechanical meta-materials

Abstract

The present invention provides meta-materials with an actively controllable mechanical property. The meta-material includes a deformable structure and a set of activation elements. The activation elements are controllable between multiple states. The meta-material includes a first value for a mechanical property when one or more of the activation elements is in the first activation state and includes a second value for the mechanical property when the activation elements have been activated to the second activation state. In one aspect, the meta-material resembles a composite material where the connectivity between the component materials or shape and arrangement of the component materials is dynamically controllable so as to affect a mechanical property of the meta-material.

What is claimed is: 
     
         1 . A method of absorbing energy using a meta-material, the meta-material comprising a deformable structure and a set of activation elements coupled to the deformable structure, the method comprising:
 activating at least one activation element from a first activation state to a second activation state, wherein the meta-material includes a first value for a mechanical property when the at least one activation element is in the first activation state and the meta-material includes a second value for the mechanical property when the at least one activation element has been activated to the second activation state; and   applying an external force to the meta-material such that the deformable structure deforms, wherein said external force is inadequate to deform said deformable structure when said at least one activation element is in said first activation state.   
     
     
         2 . The method of  claim 1 , wherein activating the at least one activation element comprises applying an electrostatic clamping voltage to the least one activation element. 
     
     
         3 . The method of  claim 1 , wherein the mechanical property is one of: toughness, elastic modulus, stiffness, damping, shape and resilience. 
     
     
         4 . The method of  claim 1 , wherein each activation element at least partially laterally overlaps an adjacent activation element. 
     
     
         5 . A meta-material comprising:
 a deformable or reconfigurable structure adapted to move or deform in a first lateral direction; and   a plurality of activation elements that mechanically couple to the deformable structure and are configured to change between a first activation state and a second activation state, wherein at least some of said plurality of activation elements each includes a rigid component and an electrode, and also partially laterally overlaps and physically contacts an adjacent activation element in a cantilevered arrangement.   
     
     
         6 . The meta-material of  claim 5 , wherein the outer surface of said deformable or reconfigurable structure is substantially covered by said plurality of activation elements where the deformable structure is adapted to move or deform in the first lateral direction. 
     
     
         7 . The meta-material of  claim 5 , wherein said deformable or reconfigurable structure is adapted to move or deform when at least a portion of said plurality of activation elements are in the second activation state but not in the first activation state. 
     
     
         8 . The meta-material of  claim 7 , wherein the second activation state is a deactivated state. 
     
     
         9 . The meta-material of  claim 5 , wherein the meta-material is configured to be selectively deformable, such that the meta-material deforms and acquires a new shape when an external force is applied to one or more of said plurality of activation elements that are in a deactivated state, and such that the meta-material does not deform or acquire a new shape when said external force is applied and when said one or more of said plurality of activation elements are in an activated state.