A system and method for perturbing a permanent magnet asymmetric field to move a body includes a rotating body configured to rotate about a rotation axis, a permanent magnet arrangement arranged on the rotating body containing two or more permanent magnets, and a perturbation element. The permanent magnet arrangement is configured such that an asymmetric magnetic field is generated by the permanent magnets about a perturbation point. Actuation of the perturbation element at or near the perturbation point causes a tangential magnetic force on the rotating body and/or the permanent magnet arrangement, thereby causing the rotating body to rotate about the rotation axis. The disclosure may also be used for linear motion of a body.

A system and method for perturbing a permanent magnet asymmetric field to move a body includes a rotating body configured to rotate about a rotation axis, a permanent magnet arrangement arranged on the rotating body containing two or more permanent magnets, and a perturbation element. The permanent magnet arrangement is configured such that an asymmetric magnetic field is generated by the permanent magnets about a perturbation point. Actuation of the perturbation element at or near the perturbation point causes a tangential magnetic force on the rotating body and/or the permanent magnet arrangement, thereby causing the rotating body to rotate about the rotation axis. The disclosure may also be used for linear motion of a body.

The disclosure describes techniques for forming nanoparticles including Fe.sub.16N.sub.2 phase. In some examples, the nanoparticles may be formed by first forming nanoparticles including iron, nitrogen, and at least one of carbon or boron. The carbon or boron may be incorporated into the nanoparticles such that the iron, nitrogen, and at least one of carbon or boron are mixed. Alternatively, the at least one of carbon or boron may be coated on a surface of a nanoparticle including iron and nitrogen. The nano particle including iron, nitrogen, and at least one of carbon or boron then may be annealed to form at least one phase domain including at least one of Fe.sub.16N.sub.2, Fe.sub.16(NB).sub.2, Fe.sub.16(NC).sub.2, or Fe.sub.16(NCB).sub.2.

This invention provides parasitic millirobots that can effectively adapt to an unstructured environment and coherently interact with diverse objects in order to fulfil various application needs. Particularly, a minimalist millirobot construction strategy by splashing composited agglutinate magnetic spray (M-spray) is adopted, which is capable of self-turning multifarious milli-/centi-objects into parasitic millirobots on-demand. Through taking full advantage of the objects' inherent structure and a covered thin drivable film, the M-spray demonstrates superior handling (from 1-D to 3-D structures) and loading capabilities (up to thousand-fold and hundred-fold of its volume and weight, respectively) while with neglectable size increment (as low as 1%) to target. Moreover, benefitting from peculiarities of online reprogramming and controllable disintegration, the parasitic millirobots can rewrite its locomotion mode according to the task and disintegrate themselves after mission accomplished, offering high adaptivity and compatibility for in vivo biomedical applications. Methods for conversion and fabrication thereof are also provided.

This invention provides parasitic millirobots that can effectively adapt to an unstructured environment and coherently interact with diverse objects in order to fulfil various application needs. Particularly, a minimalist millirobot construction strategy by splashing composited agglutinate magnetic spray (M-spray) is adopted, which is capable of self-turning multifarious milli-/centi-objects into parasitic millirobots on-demand. Through taking full advantage of the objects' inherent structure and a covered thin drivable film, the M-spray demonstrates superior handling (from 1-D to 3-D structures) and loading capabilities (up to thousand-fold and hundred-fold of its volume and weight, respectively) while with neglectable size increment (as low as 1%) to target. Moreover, benefitting from peculiarities of online reprogramming and controllable disintegration, the parasitic millirobots can rewrite its locomotion mode according to the task and disintegrate themselves after mission accomplished, offering high adaptivity and compatibility for in vivo biomedical applications. Methods for conversion and fabrication thereof are also provided.

Disclosed is an AlNiCo-based hard magnetic particle containing Al, Ni, Co, Cu, Ti, and the balance of Fe. The AlNiCo-based hard magnetic particle contains Co in an amount of 10 to 17 wt %, has a coercive force of 250-450 Oe, and has a residual magnetization/coercive force rate of 0.06 or more. The AlNiCo-based hard magnetic particle according to the present invention can advantageously guarantee magnetic properties suitable for being detected by a magnetic reluctance device due to a low content of Co.

Disclosed is an AlNiCo-based hard magnetic particle containing Al, Ni, Co, Cu, Ti, and the balance of Fe. The AlNiCo-based hard magnetic particle contains Co in an amount of 10 to 17 wt %, has a coercive force of 250-450 Oe, and has a residual magnetization/coercive force rate of 0.06 or more. The AlNiCo-based hard magnetic particle according to the present invention can advantageously guarantee magnetic properties suitable for being detected by a magnetic reluctance device due to a low content of Co.

Disclosed are a magnetic particle and a security ink containing the same. The magnetic particle includes a magnetic core, and a metal coating layer formed outside the magnetic core. The magnetic particle has a surface roughness (Ra) of 0.15 μm or less. The magnetic particle according to the present invention is suitable for application to a security ink because an abnormal increase in particle size does not occur after the metal coating layer is formed.

A method of manufacturing a permanent magnet, including providing a powder composition, of which a first fraction includes ferromagnetic metal particles and a second fraction includes thermoplastic polymer particles; using the powder composition in a powder-bed based additive manufacturing process to form a part including ferromagnetic metal particles embedded in a fused thermoplastic polymer body; and subsequently conferring magnetism on the built part by arranging the finished part in a magnetic field.

A method of manufacturing a permanent magnet, including providing a powder composition, of which a first fraction includes ferromagnetic metal particles and a second fraction includes thermoplastic polymer particles; using the powder composition in a powder-bed based additive manufacturing process to form a part including ferromagnetic metal particles embedded in a fused thermoplastic polymer body; and subsequently conferring magnetism on the built part by arranging the finished part in a magnetic field.