Omnidirectional electromagnet

1. An omnidirectional electromagnet, comprising:

a ferromagnetic core which is configured as a spheroid; and

three orthogonal solenoids disposed about the core, each solenoid adapted to receive a current from a current source to control an orientation and a magnitude of a magnetic field generated by the omnidirectional electromagnet, wherein a variance between dipole moments of each solenoid is minimized when current density of each solenoid is equal, and such that a diameter of the ferromagnetic core is between 40% and 75% of a maximum outer length of an outermost solenoid of the three orthogonal solenoids.

2. The omnidirectional electromagnet of claim 1 , wherein the ferromagnetic core comprises a solid core.

3. The omnidirectional electromagnet of claim 1 , wherein the solenoids are disposed within a resin or varnish.

4. The omnidirectional electromagnet of claim 1 , wherein at least one of the three orthogonal solenoids is configured as a cuboid sleeve.

5. The omnidirectional electromagnet of claim 4 , wherein the three orthogonal solenoids are configured as cuboid sleeves, and a first of the three orthogonal solenoids is nested within a second of the three orthogonal solenoids, which is nested within a third of the three orthogonal solenoids.

6. The omnidirectional electromagnet of claim 1 , wherein at least two of the three orthogonal solenoids are intertwined with one another.

7. The omnidirectional electromagnet of claim 1 , further comprising a coolant disposed between at least two of the three orthogonal solenoids.

8. An omnidirectional electromagnet system, comprising:

a current source; and

an omnidirectional electromagnet electrically coupled to the current source, and having a ferromagnetic core which is configured as a spheroid, and

three orthogonal solenoids disposed about the core, each solenoid adapted to receive a current from the current source to control an orientation and a magnitude of a magnetic field generated by and adjacent to the omnidirectional electromagnet, wherein a variance between dipole moments of each solenoid is minimized when current density of each solenoid is equal, and such that a diameter of the ferromagnetic core is between 40% and 75% of a maximum outer length of an outermost solenoid of the three orthogonal solenoids.

9. The omnidirectional electromagnet system of claim 8 , further comprising a control system for controlling current to the omnidirectional electromagnet to coordinate orientation and magnitude of the magnetic field of the omnidirectional electromagnet to control at least one of a position and an orientation of an object, or to control at least one of a force and a torque applied to an object.

10. The omnidirectional electromagnet system of claim 8 , further comprising one or more additional omnidirectional electromagnets electrically coupled to the current source.

11. The omnidirectional electromagnet system of claim 10 , further comprising a control system for controlling current to the omnidirectional electromagnets to coordinate orientation and magnitude of the magnetic field of the omnidirectional electromagnets to control at least one of a position and an orientation of an object, or to control at least one of a force and a torque applied to an object.

12. A method of manipulating the object of claim 9 , comprising:

a. associating the object with the magnetic field of the omnidirectional electromagnets; and

b. adjusting an orientation and magnitude of the magnetic field in order to move the object.

13. The method of claim 12 , wherein the device is at least one of a capsule endoscope device, a magnetic catheter device, a cochlear implant, a device within an eye, a device within a urinary or reproductive system, a device within the brain or spine, and a device for medical procedures on a developing fetus.

14. The method of claim 12 , wherein the device is at least one of a microscale device under the guidance of an optical microscope, a device in outer-space, and a device within a pipe or pipe-like structure.

15. The omnidirectional electromagnet of claim 1 , wherein the diameter of the ferromagnetic core is between 55% and 65% of the maximum outer length of the outermost solenoid.

16. The omnidirectional electromagnet of claim 1 , wherein the wherein the variance in dipole moment (m) of each solenoid is zero when current density (J) of each solenoid is equal (i.e. m x =m y =m z when J x =J y =J z ).

17. The omnidirectional electromagnet of claim 1 , wherein each of the three orthogonal solenoids have square-cross-section geometries which minimize a quadrupole term in a multipole expansion for the magnetic field produced by the solenoids, where the quadrupole term is proportional to:

(15 W 2 −15 L 2 +40 T 2 +30 TW )(4 T 2 +6 TW + 3 W 2 )−16 T 4

where W is inner width, L is length, and T is thickness.

18. The omnidirectional electromagnet of claim 17 , wherein the quadrupole term is equal to zero.