Devices and methods to form a randomly ordered array of magnetic beads and uses thereof

A device for forming an array of magnetic particles, the device comprising:

• a substrate comprising a plurality of magnetic regions having gaps between them, wherein the substrate comprises a surface, and wherein the magnetic regions produce a plurality of localized magnetic fields when magnetized, wherein the magnetic regions have a maximum length parallel to the surface of the substrate and a maximum width parallel to the surface of the substrate, and wherein a plurality of regions are spaced apart along the dimension of the maximum length and a plurality of regions are spaced apart along the dimension of the maximum width, so that the distance separating adjacent regions in the dimension of the maximum length is less than the distance separating adjacent regions in the dimension of the maximum width, and, wherein the localized magnetic fields are sufficient to trap a magnetic particle with a trapping energy at least three times greater than the thermal energy of the particle at room temperature, wherein the magnetic regions project above the surface of the substrate, and wherein the magnetic regions comprise a layer of magnetic material and a layer of nonmagnetic material, wherein the layer of nonmagnetic material is located between the substrate and the layer of magnetic material.

A device for forming an array of magnetic particles, the device comprising:

• a substrate comprising a plurality of magnetic regions having gaps between them, wherein the substrate comprises a surface, wherein the magnetic regions have a maximum length parallel to the surface of the substrate and a maximum width parallel to the surface of the substrate with the maximum length being greater than the maximum width, and wherein the magnetic regions produce a plurality of localized magnetic fields when magnetized, and wherein adjacent magnetic regions are so aligned with one another in the directions of their maximum length that the localized magnetic fields are sufficient to trap a magnetic particle between adjacent magnetic regions with a trapping energy at least three times greater than the thermal energy of the particle at room temperature and the gaps are available for fluid flow among them and are also available for occupancy by magnetic particles prior to introduction of magnetic particles to the device so that forces generated by the localized magnetic fields between adjacent regions can trap magnetic particles in the gaps between them, wherein at least a portion of the device comprises a biocompatible material.

A device for forming an array of magnetic particles, the device comprising:

• a substrate comprising a plurality of magnetic regions having gaps between them, wherein the substrate comprises a surface, wherein the magnetic regions have a maximum length parallel to the surface of the substrate and a maximum width parallel to the surface of the substrate with the maximum length being greater than the maximum width, and wherein the magnetic regions produce a plurality of localized magnetic fields when magnetized, and wherein adjacent magnetic regions are so aligned with one another in the directions of their maximum length that the localized magnetic fields are sufficient to trap a magnetic particle between adjacent magnetic regions with a trapping energy at least three times greater than the thermal energy of the particle at room temperature and the gaps are available for fluid flow among them and are also available for occupancy by magnetic particles prior to introduction of magnetic particles to the device so that forces generated by the localized magnetic fields between adjacent regions can trap magnetic particles in the gaps between them, further comprising a flux circulator disposed around the magnetic regions.

A device for forming an array of magnetic particles, the device comprising:

• a substrate comprising a plurality of magnetic regions having gaps between them, wherein the substrate comprises a surface, wherein the magnetic regions have a maximum length parallel to the surface of the substrate and a maximum width parallel to the surface of the substrate with the maximum length being greater than the maximum width, and wherein the magnetic regions produce a plurality of localized magnetic fields when magnetized, and wherein adjacent magnetic regions are so aligned with one another in the directions of their maximum length that the localized magnetic fields are sufficient to trap a magnetic particle between adjacent magnetic regions with a trapping energy at least three times greater than the thermal energy of the particle at room temperature and the gaps are available for fluid flow among them and are also available for occupancy by magnetic particles prior to introduction of magnetic particles to the device so that forces generated by the localized magnetic fields between adjacent regions can trap magnetic particles in the gaps between them, farther comprising a plurality of photodetectors located in proximity to locations for trapping the magnetic particles so as to detect an optical signal from trapped particles.

A device for forming an array of magnetic particles, the device comprising:

• a substrate comprising a plurality of magnetic regions, wherein the substrate comprises a surface, and wherein the localized magnetic regions produce a plurality of localized magnetic fields concentrated in gaps between the regions, and wherein the magnetic regions project above the surface of the substrate and have a maximum length parallel to the surface of the substrate and a maximum width parallel to the surface of the substrate, with the maximum length being greater than the maximum width, wherein a plurality of regions are spaced apart along the dimension of the maximum length and a plurality of regions are spaced apart along the dimension of the maximum width, and wherein the distance separating adjacent regions in the dimension of the length is less than the distance separating adjacent regions in the dimension of the width, further comprising a plurality of magnetic particles wherein the magnetic regions project above the surface of the substrate, and wherein the magnetic regions comprise a layer of magnetic material and a layer of nonmagnetic material, wherein the layer of nonmagnetic material is located between the substrate and the layer of magnetic material.