Coherent acoustic wave generation

1. An acoustic wave generator comprising:

a stack comprising:

a plurality of first layers configured to receive electrical and/or magnetic energy; and

a plurality of second layers configured in contact with the plurality of first layers, the plurality of second layers comprising one or more materials configured to change mechanical properties when electrical and/or magnetic energy is applied thereto; and

at least one source configured in operational communication with the plurality of first layers and configured to supply at least one of phased electrical and/or magnetic energy to the plurality of first layers,

wherein the stack is configured to (i) generate phased acoustic energy and (ii) at least one of amplify and store the generated acoustic energy in a first state and release said generator acoustic energy in a second state.

2. The acoustic wave generator of claim 1 , wherein at least one of the plurality of first layers comprises an electrode.

3. The acoustic wave generator of claim 1 , wherein at least one layer of the plurality of second layers comprises at least one of a piezoelectric material and a magnetostrictive material.

4. The acoustic wave generator of claim 3 , wherein at least one layer of the plurality of second layers comprises a piezoelectric ceramic or a piezoelectric crystal.

5. The acoustic wave generator of claim 1 , wherein the plurality of first layers and the plurality of second layers form a stack with a repeating pattern of a first layer, followed by a second layer, followed by another first layer, followed by another second layer.

6. The acoustic wave generator of claim 1 , further comprising a gate configured to have a closed state and an open state, wherein when the gate is in the closed state the stack is in the first state and when the gate is in the open state the stack is in the second state.

7. The acoustic wave generator of claim 6 , wherein the gate is formed of a metamaterial.

8. The acoustic wave generator of claim 1 , further comprising a horn configured to modify an acoustic impedance of the generated phased acoustic energy prior to transmission of the phased acoustic energy from the acoustic wave generator.

9. The acoustic wave generator of claim 8 , wherein the horn is configured to match an impedance of the generated phased acoustic energy with an impedance of a material into which the phased generated acoustic energy is to be transmitted.

10. The acoustic wave generator of claim 1 , further including at least one third layer in the stack, the third layer configured to store acoustic energy when the stack is in the first state.

11. The acoustic wave generator of claim 10 , wherein the at least one third layer comprises a high Q Factor material.

12. A method of transmitting acoustic energy comprising:

Generating phased acoustic energy within a stack having a plurality of first layers and a plurality of second layers;

storing the phased generated acoustic energy within the stack in a first state; and

releasing the phased generated acoustic energy within the stack in a second state.

13. The method of claim 12 , wherein the plurality of first layers are configured to receive electrical and/or magnetic energy, and the plurality of second layers are configured in contact with the plurality of first layers, the plurality of second layers comprising one or more materials configured to change mechanical properties when electrical and/or magnetic energy is applied thereto.

14. The method of claim 12 , further comprising:

closing a gate to place the stack in the first state; and

opening the gate to place the stack in the second state.

15. The method of claim 12 , further comprising altering the acoustic impedance of the generated phased acoustic energy to match an acoustic impedance of a material into which the acoustic energy is to be transmitted.