Ambient energy harvesting device with charge-carrying movable electrode
Systems, apparatuses and methods for harvesting ambient energy involve an electrically conductive charge-carrying movable electrode. An apparatus includes an electrically conductive charge-carrying electrode, a first dielectric interface region, a second dielectric interface region, and at least one reference electrode. The first and second dielectric interface regions differ in surface charge density. In certain aspects, the movable electrode moves proximate and relative to the first and second dielectric interface regions in response to receipt of ambient energy, thereby providing first and second capacitances. The first capacitance differs from the second capacitance, and/or the first surface charge density differs from the second surface charge density. Movement of the movable electrode in combination with the differing capacitances and/or charge densities results in energy accumulation, thereby enabling ambient energy to be harvested efficiently and effectively.
1. An apparatus for harvesting ambient energy, the apparatus comprising:
an electrically conductive charge-carrying movable electrode;
a first dielectric interface region having a first surface charge density;
a second dielectric interface region having a second surface charge density; and
at least one reference electrode;
wherein the apparatus is configured for relative movement of the movable electrode in response to receipt of ambient energy between (i) a first position proximate to the first dielectric interface region, yielding a first state of the apparatus and (ii) a second position in which the movable electrode is proximate to the second dielectric interface region, yielding a second state of the apparatus;
wherein when the apparatus is in the first state, the movable electrode, the first dielectric interface region, and the at least one reference electrode provide a first capacitance, and when the apparatus is in the second state, the movable electrode, the second dielectric interface region, and the at least one reference electrode provide a second capacitance;
wherein the apparatus is configured such that the movable electrode closes a first conductive path with the at least one reference electrode when the apparatus is in the first state, and the movable electrode closes a second conductive path with the at least one reference electrode when the apparatus is in the second state; and
wherein the apparatus comprises at least one of the following features (a) or (b): (a) the first capacitance differs from the second capacitance, or (b) the first surface charge density differs from the second surface charge density.
2. The apparatus of claim 1 , wherein the first capacitance differs from the second capacitance.
3. The apparatus of claim 2 , wherein the apparatus further comprises an electrical charge source in the first conductive path.
4. The apparatus of claim 1 , wherein the first surface charge density differs from the second surface charge density.
5. The apparatus of claim 4 , wherein the first surface charge density differs from the second surface charge density, and the apparatus further comprises an electrical charge source in the first conductive path.
6. The apparatus of claim 1 , wherein the first capacitance differs from the second capacitance, and the first surface charge density differs from the second surface charge density.
7. The apparatus of claim 6 , wherein the apparatus further comprises an electrical charge source in the first conductive path.
8. The apparatus of claim 1 , wherein the movable electrode comprises a liquid droplet.
9. The apparatus of claim 8 , wherein the liquid droplet comprises water or mercury.
10. The apparatus of claim 1 , wherein the first dielectric interface region comprises a different thickness than the second dielectric interface region.
11. The apparatus of claim 1 , wherein the first dielectric interface region is compositionally different from the second dielectric interface region.
12. The apparatus of claim 1 , wherein the apparatus is configured such that the movable electrode closes a third conductive path with the at least one reference electrode when the apparatus is in an intermediate state between the first state and the second state.
13. The apparatus of claim 12 , wherein the apparatus further comprises an electrical charge source in the first conductive path.
14. The apparatus of claim 1 , wherein the apparatus is configured such that a continuous conductive path is provided between the movable electrode and the at least one reference electrode when the apparatus is operated between the first state and the second state.
15. The apparatus of claim 1 , wherein the at least one reference electrode comprises a common reference electrode.
16. The apparatus of claim 1 , wherein the at least one reference electrode comprises a first reference electrode associated with the first dielectric interface region, and a second reference electrode associated with the second dielectric interface region.
17. The apparatus of claim 1 , wherein:
the first dielectric interface region is arranged between the movable electrode and the at least one reference electrode; and
the second dielectric interface region is arranged between the movable electrode and the at least one reference electrode.
18. A method for harvesting ambient energy utilizing an apparatus comprising an electrically conductive charge-carrying movable electrode, a first dielectric interface region having a first surface charge density, a second dielectric interface region having a second surface charge density, and at least one reference electrode, the method comprising:
effecting, in response to receipt of ambient energy, relative movement of the movable electrode between a first position proximate to the first dielectric interface region, yielding a first state of the apparatus and a second position proximate to the second dielectric interface region, yielding a second state of the apparatus;
closing, by the movable electrode, a first conductive path with the at least one reference electrode when the apparatus is in the first state, thereby inducing a first current in the first conductive path, the movable electrode, the first dielectric interface region, and the at least one reference electrode providing a first capacitance when the apparatus is in the first state; and
closing, by the movable electrode, a second conductive path with the at least one reference electrode when the apparatus is in the second state, thereby inducing a second current in the second conductive path, the movable electrode, the second dielectric interface region, and the at least one reference electrode providing a second capacitance when the apparatus is in the second state, an amplitude of the second current dependent on at least one of the following features (a) or (b): (a) a difference between the first capacitance and the second capacitance, or (b) a difference between the first surface charge density and the second surface charge density.
19. The method of claim 18 , wherein the amplitude of the second current is dependent on a difference between the first capacitance and the second capacitance.
20. The method of claim 18 , wherein the amplitude of the second current is dependent on a difference between the first surface charge density and the second surface charge density.
21. The method of claim 18 , wherein the amplitude of the second current is dependent on both (i) a difference between the first capacitance and the second capacitance, and (ii) a difference between the first surface charge density and the second surface charge density.