Super-capacitor and arrangement for miniature implantable medical devices
An energy storage device includes first and second electrodes and a solid state electrolyte. The first electrode includes carbon nanotubes, a conductive polymer, and a metallization on said carbon nanotubes. The second electrode similarly includes carbon nanotubes, a conductive polymer, and a metallization on said carbon nanotubes. The solid state electrolyte is disposed at least in part between the first electrode and the second electrode. In at least some embodiments, the conductive polymer of the first electrode includes polyaniline, and the metallization of the first electrode is a gold metallization.
1. An energy storage device, comprising:
a first electrode comprising a first plurality of carbon nanotubes, a first metallization layer disposed on said first plurality of carbon nanotubes, and a first conductive polymer disposed on said first metallization layer;
a second electrode comprising a second plurality of carbon nanotubes a second metallization layer disposed on said second plurality of carbon nanotubes, and a second conductive polymer disposed on said second metallization layer; and
a solid state electrolyte disposed at least in part between the first electrode and the second electrode,
wherein the first metallization layer and the first conductive polymer are permeated throughout the first plurality of carbon nanotubes,
wherein the first metallization comprises a gold metallization at a thickness of 300 nm applied by sputtering, and
wherein an energy storage device formed of the first electrode and the second electrode can form any shape having a cross sectional area down to 1 mm 2 .
2. The energy storage device of claim 1 , wherein the first conductive polymer of the first electrode is disposed at least in part between the first plurality of carbon nanotubes of the first electrode and the solid state electrolyte.
3. The energy storage device of claim 2 , wherein the first conductive polymer of the first electrode includes polyaniline.
4. The energy storage device of claim 1 , wherein the solid state electrolyte is formed from polyvinylidene fluoride-co-hexa-fluoropropylene.
5. A method of fabricating at least a part of an energy storage device, comprising:
a) providing a first layer of conductive carbon nanostructures;
b) applying metal by sputtering to the first layer of conductive carbon nanostructures;
c) providing polyaniline on the first layer of conductive carbon nanostructures and the applied metal to form a first electrode; and
d) forming a solid state electrolyte on the first electrode,
wherein the metal and the polyaniline are permeated throughout the first layer of conductive carbon nanostructures,
wherein the metal comprises gold at a thickness of 300 nm, and
wherein an energy storage device formed of the first electrode can form any shape having a cross sectional area down to 1 mm 2 .
6. The method of claim 5 , wherein step d) further includes immersing the first electrode in a solution containing an electrolytic mixture.
7. The method of claim 6 , wherein step d) further includes curing the solid state electrolyte on the first electrode after removing the first electrode from the electrolytic mixture.
8. The method of claim 6 , wherein the electrolytic mixture includes an acid and polyvinyl alcohol.
9. The method of claim 5 , wherein step a) further comprises providing the first layer of conductive carbon nanostructures as a plurality of carbon nanotubes.
10. A wireless power management arrangement in a receiver for implantable medical devices, comprising:
an energy harvesting apparatus to include thermal, mechanical, and electromagnetic harvesting, the energy harvesting apparatus configured to receive energy wirelessly and generate electrical energy;
a first capacitor coupled to receive the generated electrical energy and configured to collect electrical charge associated with the received electrical energy, the first capacitor configured for reversible redox reactions at or near an electrode surface;
a boost converter coupled to the first capacitor configured to boost voltage from the first capacitor; and
a second capacitor operably coupled to the boost converter to collect electrical charge based on the boost voltage,
wherein the first capacitor includes
a first electrode comprising a first plurality of carbon nanotubes, a first metallization layer disposed on said first plurality of carbon nanotubes, and a first conductive polymer disposed on said first metallization layer;
a second electrode comprising a second plurality of carbon nanotubes a second metallization layer disposed on said second plurality of carbon nanotubes, and a second conductive polymer disposed on said second metallization layer; and
a solid state electrolyte disposed at least in part between the first electrode and the second electrode,
wherein the first metallization layer and the first conductive polymer are permeated throughout the first plurality of carbon nanotubes,
wherein the first metallization comprises a gold metallization at a thickness of 300 nm applied by sputtering, and
wherein an energy storage device formed of the first electrode and the second electrode can form any shape having a cross sectional area down to 1 mm 2 .
11. The wireless power management arrangement of claim 10 , wherein the energy harvesting apparatus comprises an antenna and an RF rectifier, and wherein the first capacitor is operably coupled to receive rectified RF energy from the RF rectifier.
12. The wireless power arrangement of claim 10 , wherein the second capacitor is configured to regulate the boost voltage.