Bichromal Janus Particles, Microspheres, Microbeads – Stock selection or Custom-made
Cospheric offers unique capability to manufacture Janus microspheres and microparticles with partial coatings and dual functionality. Currently half-shell or hemispherical coatings can be applied to any sphere (glass, polymer, ceramic) in sizes 45micron in diameter and higher. Coatings can be customized for any color and coverage of between 20% to 60% of the sphere. Each coating is custom formulated for color, charge, magnetic, electric, and surface properties, and solvent resistance per customers’ needs.
Hemispherical coatings of less than 1 micron with tolerances as low as 0.25 micron have been routinely demonstrated. Color combinations are truly unlimited. White, black, silver, blue, green, red, yellow, brown, purple as well as transparent microspheres have been made. Sphericity of greater than 90% and custom particle size ranges are offered.
We have successfully coated solid and hollow glass microsphere, including soda-lime, borosilicate, and barium titanate glass microspheres. We have also coated on silver.
Optically anisotropic spheres and janus particles with magnetic half-shells have been originally developed for applications in electronic displays, such as e-paper, but are now widely used in numerous applications in diagnostics, medical research, microscopy and biotechnology, as well as electronics, due to their ability to orient themselves in response to electromagnetic field and show a visual response. This is achieved by making spheres both bipolar and bichromal, with dipole precisely aligned with two differently colored hemispheres. As the spheres align themselves, the viewer will observe the color of one hemisphere, while the other hemisphere will be hidden from view, providing an obvious strong visible indication of the presence of the field or other stimuli. In alternating electromagnetic field, these microspheres have been proven to spin at hundreds of times per second.
Magnetic Microspheres – Paramagnetic
Magnetic microspheres, more accurately called paramagnetic microspheres have unique properties that are useful for a variety of applications.
Paramagnetism is a form of magnetism that occurs only in the presence of an externally applied magnetic field. Paramagnetic materials are attracted to magnetic fields and hence have a relative magnetic permeability of ≥1 (a positive magnetic susceptibility). The magnetic moment induced by the applied field is linear in the field strength and rather weak.1
Magnetic Microspheres – New Size Ranges Offered
Cospheric announces new particle size ranges for its BKPMS, Paramagnetic Microsphere product.
Thanks to customer demand for narrower particle size ranges of paramagnetic microspheres. These highly opaque microspheres are homogeneous PE and often used in microscopy for high contrast cross sections.
Cospheric has added the following sizes to its extensive inventory of microspheres offered in the dry powder form:
- 10-20 micron, 0.1 grams
- 20-27 micron, 0.5 grams
- 27-32 micron, 1.0 grams
- 32-38 micron, 5.0 grams
- 38-45 micron, 5.0 grams
These sizes are in addition to its extensive range of black magnetic microspheres available up to 1.0mm (1000 micron) in diameter.
Paramagnetic microspheres have the ability to increase in magnetization with an applied magnetic field and loose their magnetism when the field is removed. Neither hysteresis nor residual magnetization is observed and that provides the end use two very practical advantages:
- When the filed is removed, the microspheres demagnetize and re-disperse easily. This property allows efficient washing steps, low background and good reproducibility.
- The behavior of the microspheres is always the same whatever the magnetization cycles may be. Such behavior is a key point for automated instrument.
Recently black paramagnetic microspheres have been produced in larger sizes of 10 micron to 1mm (1000um) and in dry form enabling scientists to leverage the benefits of paramagnetic particles in new applications. These highly spherical polyethylene microspheres offer the flow-ability of standard microspheres, with the ability to be separated from other materials for re-use and cleanup.
One use of paramagnetic microspheres as large as 1mm in diameter to simulate salmon eggs, Scientists are able to place them in a natural habitat, observe how they move with the water currents and then use their magnetic properties to clean them up.
SuperParamagnetic microspheres, sometimes just called magnetic microspheres or paramagnetic microspheres have become widely used in the life sciences industry (<10um diameters) for applications such as:
- Solid Phase Immunoassays
- Bacteria Detection
- High Throughput screening
- Rapid Tests
- Cell Sorting
- Nucleic Acids Technology
Super paramagnetic microspheres used in the life science industry are supplied in solution form.