Thermoacoustic meta-structure

An infrastructural barrier comprising:

• a plurality of thermoacoustic metastructures, each thermoacoustic metastructure comprising:
• a resonator having a surrounding wall defining an opening, the surrounding wall having a first end and a second end opposite the first end, the first end forming an aperture operable to receive a working fluid, the second end forming an end-stop, the resonator having a resonator length between the first end and the second end;
• a porous stack having a first side and a second side opposite the first side, the porous stack disposed in the opening defined by the surrounding wall and in fluid communication with the working fluid;
• a thermopile comprising a plurality of thermoelectric transducers electrically coupled to form a thermopile circuit operable to generate electrical energy, the thermoelectric transducers being alternatingly coupled to a first location and a second location of the porous stack, the first location being spaced longitudinally from the second location;
• and
• a modular housing supporting the resonator, the porous stack, and the thermopile;
• and
• at least one power circuitry electrically coupled to the thermopile circuit of one or more thermoacoustic metastructure and operable to receive the generated electrical energy;
• and
• wherein the modular housing of each of the plurality of thermoacoustic metastructures is interlocked with at least one adjacent thermoacoustic metastructure.

A method of making a thermoacoustic metastructure, comprising:

• in any order,
• positioning a porous stack having first and second ends into a resonator, the porous stack having a non-uniform geometry along at least one direction of the stack;
• and
• connecting a thermopile to a first location and a second location of the porous stack, the first location being longitudinally spaced from the second location.