Multi-layer phononic crystal thermal insulators

Abstract

A thermal insulator includes a plurality of layers. At least some of the layers include phononic crystals having a phononic bandgap, wherein heat transporting phonons within a selected range of frequencies are substantially blocked by each phononic crystal layer. The plurality of layers thermally isolate a first region from a second region, wherein the first region is at one end of the plurality of layers and the second region is at the other end of the plurality of layers.

What is claimed is: 
     
         1 . A method for providing thermal insulation, comprising:
 providing a plurality of layers, at least some of the layers comprising phononic crystals having a phononic bandgap, wherein heat transporting phonons within a selected range of frequencies are substantially blocked by each layer comprising phononic crystals; and   arranging the plurality of layers into a multilayer structure, wherein the layers comprising phononic crystals are arranged in a sequence having at least one of an increasing or a decreasing order according to a phononic bandgap frequency associated with each of the layers comprising phononic crystals to form a continuous gradation of phononic bandgaps.   
     
     
         2 . The method of  claim 1 , wherein each layer comprises a different material combination than every other layer. 
     
     
         3 . The method of  claim 1 , wherein at least one layer comprises voids defined within the layer in order to alter that layer's phononic bandgap. 
     
     
         4 . The method of  claim 1 , wherein phononic crystals associated with at least one layer comprise a periodic array of two different solid materials. 
     
     
         5 . The method of  claim 1 , wherein phononic crystals associated with a first layer have different lattice spacing than phononic crystals associated with a second layer. 
     
     
         6 . The method of  claim 1 , wherein at least one layer comprises at least one of doping atoms, nanoparticles, nanowires, nanocrystals, nanopores, lithographically defined features, nano-machined nano holes, nanofibers, or nanofilaments. 
     
     
         7 . The method of  claim 1 , wherein at least one layer comprises at least one of 1-dimensional crystals, 2-dimensional crystals, or 3-dimensional crystals. 
     
     
         8 . A method for providing a thermal insulator, comprising:
 providing a plurality of layers, at least some of the layers comprising phononic crystals having a phononic bandgap, wherein heat transporting phonons within a selected range of frequencies are substantially blocked by each layer comprising phononic crystals; and   arranging the plurality of layers into a sequence having random phononic bandgap jumps, the random phononic bandgap jumps counteracting a rethermalization of energy as the heat transporting phonons propagate through the plurality of layers.   
     
     
         9 . The method of  claim 8 , wherein each layer comprises a different material combination than every other layer. 
     
     
         10 . The method of  claim 8 , wherein at least one layer comprises voids defined within the layer in order to alter that layer's phononic bandgap. 
     
     
         11 . The method of  claim 8 , wherein phononic crystals associated with at least one layer comprise a periodic array of two different solid materials. 
     
     
         12 . The method of  claim 8 , wherein phononic crystals associated with a first layer have different lattice spacing than phononic crystals associated with a second layer. 
     
     
         13 . The method of  claim 8 , wherein at least one layer comprises at least one of doping atoms, nanoparticles, nanowires, nanocrystals, nanopores, lithographically defined features, nano-machined nano holes, nanofibers, or nanofilaments. 
     
     
         14 . The method of  claim 8 , wherein at least one layer comprises at least one of 1-dimensional crystals, 2-dimensional crystals, or 3-dimensional crystals. 
     
     
         15 . An insulated system, comprising:
 a plurality of laterally arranged insulators each comprising:
 a plurality of layers, at least some of the layers comprising phononic crystals having a phononic bandgap, wherein heat transporting phonons with a selected range of frequencies are substantially blocked by each layer comprising phononic crystals; 
 wherein the plurality of layers are arranged into a sequence having random phononic bandgap jumps, the random phononic bandgap jumps counteracting a rethermalization of energy as the heat transporting phonons propagate through the plurality of layers; 
   wherein each of the insulators are coupled to at least one other insulator.   
     
     
         16 . The system of  claim 15 , wherein at least one phononic crystal layer is coupled to an apparatus. 
     
     
         17 . The system of  claim 16 , wherein the apparatus includes a turbine blade. 
     
     
         18 . The system of  claim 16 , wherein the apparatus includes an electronic device. 
     
     
         19 . The system of  claim 15 , wherein at least one phononic crystal layer is configured for use with a heat sensor. 
     
     
         20 . The system of  claim 15 , wherein at least one phononic crystal layer comprises at least one of doping atoms, nanoparticles, nanowires, nanocrystals, nanopores, lithographically defined features, nano-machined nano holes, nanofibers, or nanofilaments.