Electrode design and low-cost fabrication method for assembling and actuation of miniature motors with ultrahigh and uniform speed
The invention includes miniature dots, miniature disks or miniature cylinders and methods of making the same by dispersing a particle in or on a dissolvable, meltable or etchable layer on a substrate, a portion of the particle exposed above a surface of the dissolvable, meltable or etchable layer; depositing a mask on the particles and the dissolvable substrate; removing the particles from the layer; etching an array of nanoholes in the substrate; depositing one or more metallic layers into the nanoholes to form an array of dots, disks or cylinders; and dissolving the dissolvable layer with a solvent to expose the dots, disks or cylinders. The dots, disks or cylinders can be included with two sets of microelectrodes for ultrahigh speed rotation of miniature motors, and/or can be designed with a magnetic configuration into miniature motors for uniform rotation speeds and prescribed angular displacement. The invention also includes modified diatom frustules, and miniature motors containing modified diatom frustules.
1. A motor comprising:
a) a substrate;
b) a rotor;
c) a nanobearing comprising a plurality of layers, said plurality of layers comprising;
i) an adhesion layer coupled to the substrate;
ii) a non-magnetic layer distal to the substrate and proximate to the rotor; and
iii) a magnetic layer disposed between the adhesion layer and the non-magnetic layer;
said layers arranged along a longitudinal axis perpendicular to the substrate;
and
d) a quadrupole electrode
wherein the magnetic layer comprises:
cobalt in combination with at least one metal selected from platinum, iron, nickel, and silver; or
iron in combination with at least one metal selected from platinum, cobalt, nickel, and silver;
wherein the rotor has a first end and second end opposite and spaced apart, wherein said first and second ends are circumferentially rotatable in a plane perpendicular to the longitudinal axis, wherein the rotation is not sinusoidal and does not exhibit periodic oscillations in speed.
2. The motor of claim 1 , wherein the adhesion layer comprises chromium, titanium, or a combination thereof.
3. The motor of claim 1 , wherein the non-magnetic layer present in the magnet bearing comprises chromium, gold, titanium, diamond thin film, graphene, graphite, silver, or copper.
4. The motor of claim 1 , wherein the rotor is a nanowire.
5. The motor of claim 4 , wherein the nanowire is Au/Ni/Au.
6. The motor of claim 1 , wherein the rotor comprises a modified diatom frustule.
7. The motor of claim 6 , wherein the modified diatom frustule comprises a mask layer covering a portion of the frustule, said mask layer comprising a plurality of nanoholes comprising at least one metallic layer.
8. The motor of claim 7 , wherein the metallic layer in the mask layer comprises a mask-non-magnetic layer, a mask-magnetic layer, and a mask-adhesion layer.
9. The motor of 8 , wherein the mask-non-magnetic layer comprises Cr, Au, Ti, carbon, graphene, graphite, SiO 2 , Ag, Cu or a combination thereof, the mask-magnetic layer comprises Ni, Co, Fe, alloys thereof, or a combination thereof, and the mask-adhesion layer comprises Cr or Ti.
10. The motor of claim 9 , wherein the mask-non-magnetic layer comprises Au, the mask-magnetic layer comprises Ni, and the mask-adhesion layer comprises Cr.
11. The motor of claim 1 , wherein the nanobearing exhibits a perpendicular magnetic anisotropy.
12. The motor of claim 1 , wherein the nanobearing has a diameter from about 200 nm to about 500 nm.
13. The motor of claim 1 , wherein the rotor exhibits a perpendicular magnetic anisotropy, in-plane magnetic anisotropy, or a mixed magnetic anisotropy relative to a plane of motor rotation.
14. The motor of claim 1 , wherein the motor is a step motor.
15. The motor of claim 1 , wherein the motor is configured to provide from about 500,000 to about 2,000,000 rotations without failure.
16. A motor comprising:
a) a substrate;
b) a rotor having a perpendicular anisotropy;
c) a nanobearing comprising a plurality of layers, said plurality of layers comprising and having a perpendicular anisotropy;
iv) an adhesion layer coupled to the substrate;
v) a non-magnetic layer distal to the substrate and proximate to the rotor; and
vi) a magnetic layer disposed between the adhesion layer and the non-magnetic layer;
said layers arranged along a longitudinal axis perpendicular to the substrate;
and
d) a quadrupole electrode
wherein the magnetic layer comprises:
cobalt in combination with at least one metal selected from platinum, iron, nickel, and silver; or
iron in combination with at least one metal selected from platinum, cobalt, nickel, and silver;
wherein the rotor has a first end and second end opposite and spaced apart, wherein said first and second ends are circumferentially rotatable in a plane perpendicular to the longitudinal axis, wherein the rotation is not sinusoidal and does not exhibit periodic oscillations in speed; and wherein the motor is a step motor.