Non-hermitian complementary metamaterials (nhcmms), systems including an nhcmm, and methods utilizing an nhcmm

Abstract

A non-Hermitian complementary metamaterial (NHCMM). Acoustic transmission systems including an acoustic wave generator configured to generate an acoustic wave and propagate the acoustic wave through a tissue of a specimen, and the NHCMM, which is configured to add a first amount of energy amplification coherently to the acoustic wave to account for energy loss in the acoustic wave as a result of the wave propagating through the tissue of the specimen. The acoustic wave generator can be an ultrasound generator, and the tissue can be a cranium.

What is claimed is: 
     
         1 . A non-Hermitian complementary metamaterial (NHCMM). 
     
     
         2 . The NHCMM of  claim 1  comprising:
 resonating structures; and 
 active gain elements; 
 wherein negative real parts of the NHCMM are realized by the resonating structures; and 
 wherein imaginary parts of the NHCMM are contributed by the active gain elements. 
 
     
     
         3 . The NHCMM of  claim 1 , wherein the NHCMM is an isotropic metamaterial. 
     
     
         4 . The NHCMM of  claim 1 , wherein the NHCMM inherently embodies the non-conservation of energy. 
     
     
         5 . A system comprising the NHCMM of  claim 1 ;
 wherein the NHCMM is configured to add a first amount of energy amplification coherently to an acoustic wave passing therethrough to account for an energy loss in the acoustic wave as a result of the wave propagating through a specimen.   
     
     
         6 . The system of  claim 5 , wherein the NHCMM is configured as a layer;
 wherein the layer of NHCMM is configured to add a first amount of energy amplification coherently to an acoustic wave passing therethrough to account for an energy loss in the acoustic wave as a result of the wave propagating through the specimen; and   wherein the NHCMM is positioned proximate the specimen.   
     
     
         7 . The system of  claim 5  further comprising:
 a processing system comprising one or more processors; and 
 a memory storing instructions that, when executed by the processing system, cause the system to:
 calculate an impedance mismatch and an intrinsic loss of the specimen, based at least in part on a first bulk modulus and a first density of the NHCMM, and a second bulk modulus and a second density of the specimen; and 
 alter the NHCMM to compensate for the calculated impedance mismatch and the intrinsic loss. 
 
 
     
     
         8 . The system of  claim 5  further comprising:
 an acoustic wave generator configured to generate an acoustic wave and propagate the acoustic wave through the specimen; 
 wherein the NHCMM is configured to add a first amount of energy amplification coherently to the acoustic wave passing therethrough to account for the energy loss in the acoustic wave as a result of the wave propagating through the specimen. 
 
     
     
         9 . A non-Hermitian complementary metamaterial (NHCMM) comprising:
 resonating structures; and   active gain elements;   wherein negative real parts of the NHCMM are realized by the resonating structures; and   wherein imaginary parts of the NHCMM are contributed by the active gain elements.   
     
     
         10 . A system comprising:
 an acoustic wave generator configured to generate an acoustic wave and propagate the acoustic wave through a specimen; and   the NHCMM of  claim 9 ;   wherein the NHCMM is configured to add a first amount of energy amplification coherently to the acoustic wave to account for energy loss in the acoustic wave as a result of the wave propagating through the specimen.   
     
     
         11 . The system of  claim 10 , wherein the NHCMM has a first bulk modulus and a first density having an opposite sign to a second bulk modulus and a second density of the specimen, respectively. 
     
     
         12 . The system of  claim 10 , wherein active gain elements in the NHCMM compensate acoustic wave attenuation through lossy material of the specimen. 
     
     
         13 . The system of  claim 10 , wherein negative real parts of the NHCMM are realized by resonating systems, while imaginary parts of the NHCMM are contributed by active gain elements. 
     
     
         14 . The system of  claim 10 , wherein active gain elements in the NHCMM compensate acoustic wave attenuation through lossy material of the specimen;
 wherein negative real parts of the NHCMM are realized by resonating systems; and   wherein imaginary parts of the NHCMM are realized by the active gain elements.   
     
     
         15 . The system of  claim 10 , wherein the NHCMM is positioned proximal to the specimen. 
     
     
         16 . The system of  claim 11  further comprising:
 a processing system comprising one or more processors; and 
 a memory storing instructions that, when executed by the processing system, cause the system to:
 calculate an impedance mismatch and an intrinsic loss of the specimen, based at least in part on the first bulk modulus and the first density of the NHCMM, and the second bulk modulus and the second density of the specimen; and 
 alter the NHCMM to compensate for the calculated impedance mismatch and the intrinsic loss. 
 
 
     
     
         17 . The system of  claim 11  further comprising:
 a processing system comprising one or more processors; and 
 a memory storing instructions that, when executed by the processing system, cause the system to:
 transmit a first acoustic wave from the acoustic wave generator to propagate the first acoustic wave through the specimen to determine the second bulk modulus and the second density of the specimen; 
 calculate an energy loss in the first acoustic wave as a result of the first acoustic wave propagating through the specimen; 
 alter the NHCMM to coherently amplify the first amount of energy to the acoustic wave generator to compensate the energy loss in the first acoustic wave to form a second acoustic wave; and 
 transmit the second acoustic wave from the acoustic wave generator into the specimen; 
 wherein the NHCMM is positioned proximal to the specimen. 
 
 
     
     
         18 . The system of  claim 11  further comprising:
 a processing system comprising one or more processors; and 
 a memory storing instructions that, when executed by the processing system, cause the system to:
 transmit a first acoustic wave from the acoustic wave generator through a tissue of the specimen to determine the second bulk modulus and the second density; 
 calculate an impedance mismatch and an intrinsic loss of the tissue; 
 alter the NHCMM to coherently amplify the first amount of energy to compensate for the impedance mismatch and the intrinsic loss; and 
 transmit a second acoustic wave from the acoustic wave generator through the tissue. 
 
 
     
     
         19 . A system comprising:
 the NHCMM of  claim 9 ;   a processing system comprising one or more processors; and   a memory storing instructions;   wherein the NHCMM is configured to add a first amount of energy amplification coherently to an acoustic wave passing therethrough to account for an energy loss in the acoustic wave as a result of the wave propagating through a lossy material;   wherein the instructions, when executed by the processing system, cause the system to:
 calculate an impedance mismatch and an intrinsic loss of the lossy material, based at least in part on a first bulk modulus and a first density of the NHCMM, and a second bulk modulus and a second density of the lossy material; and 
 alter the NHCMM to compensate for the calculated impedance mismatch and the intrinsic loss; and 
   wherein the first bulk modulus and the first density have an opposite sign to the second bulk modulus and the second density.