Conformable layer utilizing active material actuation

Abstract

A conformable protective layer, such as a fabric or covering, adapted for overlaying an object or space, and presenting a condition, such as a geometric configuration or stiffness, includes at least one shape memory alloy, electroactive polymer, or similar active material based actuator operable to undergo a reversible change when exposed to and/or removed from an external signal, and is configured such that the change is operable to autonomously modify the condition, or facilitate placement and removal of the layer.

1 . A conformable protective layer adapted for overlaying an object or space, so as to present a first condition relative thereto, said layer comprising:
 at least one shape memory alloy element operable to undergo a reversible change when exposed to or removed from exposure to an external signal,   said element being configured such that the change is operable to autonomously modify the condition.   
     
     
         2 . The layer as claimed in  claim 1 , wherein the object defines an object volume, the first condition is a first geometric configuration of the layer, wherein an internal void is defined, the void defines a void volume greater than the object volume, and the change is configured to modify the first geometric configuration, such that a second void is defined having a void volume less than the object volume, and the layer is caused to tightly overlay the object. 
     
     
         3 . The layer as claimed in  claim 1 , wherein said at least one element is in a martensitic state, and the signal is a thermal activation signal operable to heat the element. 
     
     
         4 . The layer as claimed in  claim 1 , wherein said at least one element is in an austenitic state and the signal is a tensile stress load operable to cause the element to stretch. 
     
     
         5 . The layer as claimed in  claim 1 , wherein said at least one element presents a geometric configuration selected from the group consisting essentially of singular wires, bundles, weaves, knits, cables, and braids. 
     
     
         6 . The layer as claimed in  claim 1 , wherein said at least one element is passively exposed to the signal. 
     
     
         7 . The layer as claimed in  claim 1 , wherein the layer is a fabric including a plurality of non-active material fibers, and said at least one element presents a plurality of offset shape memory alloy wires interlaced with the non-active fibers. 
     
     
         8 . The layer as claimed in  claim 7 , wherein the fibers and wires are interlaced through pantographing. 
     
     
         9 . The layer as claimed in  claim 1 , further comprising a non-active material portion, wherein the portion is extensible or contractable in plane, and the element is configured to cause the portion to contract without producing wrinkles, when activated. 
     
     
         10 . The layer as claimed in  claim 9 , wherein the element is stretched prior to overlaying the object or space. 
     
     
         11 . The layer as claimed in  claim 10 , wherein the portion is stretched prior to overlaying the object or space. 
     
     
         12 . The layer as claimed in  claim 1 , further comprising a non-active material portion, wherein the portion is elastic and flexible, and said at least one element and portion is stretched prior to overlaying the object or space. 
     
     
         13 . The layer as claimed in  claim 1 , further comprising a non-active material portion, wherein the portion is elastic and flexible, and said at least one element is pre-stretched prior to composing the layer, and the portion is over-sized relative to the object or space. 
     
     
         14 . The layer as claimed in  claim 1 , further comprising a non-active material portion, wherein the portion is inextensible in-plane and flexible in-bending. 
     
     
         15 . The layer as claimed in  claim 14 , wherein said at least one element is stretched prior to composing the layer, and the portion is over-sized relative to the object or space. 
     
     
         16 . The layer as claimed in  claim 1 , wherein the layer comprises a flexible non-active portion, said at least one element presents at least one tether coupled to the portion and operable to secure the portion relative to the object or space, and each tether presents a first configuration, when deactivated, operable to facilitate overlaying the object or space, and a second configuration, when activated, configured to exert a tensile load in, so as to increase the stiffness of, the portion. 
     
     
         17 . The layer as claimed in  claim 16 , wherein the layer composes a tent, automotive covering, boating covering, roofing tarp, covering for stock-piles, or covering for furniture. 
     
     
         18 . The layer as claimed in  claim 1 , wherein the layer composes an item of apparel, a head cover adapted for use with a golf club, a skate boot cover, reusable shrinkage wrap, a shower cap, or a swimming cap. 
     
     
         19 . A conformable fabric adapted for overlaying an object or space, so as to present a first geometric configuration relative thereto, said fabric comprising:
 a plurality of non-active material fibers, wherein the fibers are extensible or contractable in-plane, and elastic, so as to be pre-stretched prior to overlaying the object or space; and   a plurality of shape memory alloy wires interlaced with the fibers, and operable to undergo a reversible change when exposed to or removed from an external signal, wherein the wire is pre-stretched prior to overlaying the object or space,   said wires being configured such that the change is operable to autonomously modify the geometric configuration.   
     
     
         20 . A conformable protective layer adapted for overlaying an object or space, so as to present a first condition relative thereto, said layer comprising:
 at least one electroactive polymer element operable to undergo a reversible change when exposed to or removed from an external signal,   said element being configured such that the change is operable to autonomously modify the condition.