Carbon nanotube-based integrated power inductor for on-chip switching power converters

An inductor comprising:

• a substrate having a spiraled trench;
• a first coil of carbon nanotubes positioned in the spiraled trench;
• and
• a second coil of carbon nanotubes positioned in the spiraled trench, wherein the second coil is electrically separated from the first coil within the spiraled trench and spirals in a same direction as the first coil, and wherein a width of the first coil is different than a width of the second coil.

A transformer, comprising:

• a substrate having
• first coil of carbon nanotubes positioned in the spiraled trench;
• and
• second coil of carbon nanotubes positioned in the spiraled trench,
• wherein the transformer is a circuit element of a switched power converter, wherein the second coil is electrically separated from the first coil within the spiraled trench and spirals in a same direction as the first coil, and wherein a width of the first coil is different than a width of the second coil.

A magnetic circuit element, comprising:

• a substrate having a trench;
• a first coil of carbon nanotubes positioned in the trench;
• and
• a second coil of carbon nanotubes positioned in the trench, wherein the second coil is electrically separated from the first coil within the trench and extends in a same direction as the first coil, and wherein a width of the first coil is different than a width of the second coil.

A method of forming coils for an inductor, wherein the coils comprise comprises carbon nanotubes, the method comprising:

• providing a substrate;
• forming a spiraled trench in the substrate;
• and
• growing the carbon nanotubes in the spiraled trench thereby forming a first coil and a second coil in the spiraled trench, wherein the second coil is electrically separated from the first coil within the spiraled trench and spirals in a same direction as the first coil, and wherein a width of the first coil is different than a width of the second coil.

An inductor comprising:

• a substrate having a spiraled trench;
• and
• a first coil of carbon nanotubes positioned in the spiraled trench, the first coil having a first end and a second end, wherein the first coil comprises a first plurality of bundles of carbon nanotubes positioned end-to-end in the spiraled trench from the first end to the second end such that at least one carbon nanotube of each of the first plurality of bundles has an end that abuts an end of at least one carbon nanotube of an adjacent one of the first plurality of bundles
• a second coil of carbon nanotubes positioned in the spiraled trench, the second coil having a third end and a fourth end, wherein the second coil comprises a second plurality of carbon nanotubes positioned end-to-end in the spiraled trench from the third end to the fourth end such that at least one carbon nanotube of each of the second plurality of bundles has an end that abuts an end of at least one carbon nanotube of an adjacent one of the second plurality of bundles,
• wherein the second coil is electrically separated from the first coil within the spiraled trench and spirals in a same direction as the first coil, and wherein a width of the first coil is different than a width of the second coil.