ParaMagnetic Microspheres

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.

106-125um Magnetic Microspheres

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
• Biosensors
• Nucleic Acids Technology
• Microfluidics¹

Super paramagnetic microspheres used in the life science industry are supplied in solution form.

1. Merck Estapor Super Paramagnetic Microspheres Brochure

Metal Coated Microspheres – Conductive Silver Coating

From early days engineers have been looking for ways to shield circuits from electromagnetic interference (EMI). One of the most effective methods of shielding is by creating an electrically conductive enclosure around the circuit or device. This can be accomplished by using any electrically conductive material. Advances in coated microspheres have enabled the creation of light weight electrically conductive coatings that provide excellent EMI shielding.

Electrically conductive microspheres are produced by applying a metallic silver coating to the surface of the microspheres, thus giving the advantages of a metal particle with the additional properties of the core microsphere.  Typically hollow glass microspheres are silver coated as this offers the combination of a low density filler and a conductive particle.   Coatings with EMI shielding of greater than 45db have been produced by adding as little as 20% by weight of M-18 silver coated microspheres.

Cospheric offers metal coated (silver)  electrically conductive microspheres in a variety of sizes and densities as shown in the table below, custom particle size ranges are also available:

Solid Red Polyethylene Microspheres Announced

Santa Barbara, CA -  May 28, 2010 - Cospheric LLC is now offering a product line of solid red polyethylene microspheres in particle size ranges from 10um to 1000um (1mm).

Offering a bright red color.  These microspheres can be used as additives in personal care products, or in fluid flow visualization experiments.  Samples are in stock and ready to ship to customers for R&D use of product evaluation.  These high quality microspheres are specified to be greater than 90% spherical, and greater than 90% in the specified size range.

Sample Density is 0.98g/cc (Custom densities are available)

Spherical Particle sizes include:

10-27um, 27-32um (30 micron), 32-38um (35 micron), 38-45um (40 micron), 45-53um (50 micron), 53-63um (60 micron), 63-75um (70 micron), 75-90um (80 micron), 90-106um (0.1mm), 106-125um, 125-150um, 150-180um, 180-212um (0.2mm), 212-250um (0.25mm), 250-300um (0.3mm), 300-355um (0.35mm), 355-400um (0.4mm), 400-500um (0.5mm), 500-600um (0.6mm), 600-710um (0.7mm), 710-850um (0.8mm), 850-1000um (0.9mm).

Microspheres for Coatings Applications (Opaque Polyethylene)

Microspheres are well known in the coatings industry for their use as low-surface-area fillers that offer benefits in viscosity and density control, solids content, application and flow characteristics.

Cospheric LLC, a Santa Barbara-based microtechnology company, recently launched a line of opaque polyethylene microspheres that act as a superior opacifying agent and provide maximum hiding power with just one monolayer of microspheres as small as 40 microns in diameter. Microspheres are manufactured in any color imaginable and even in combinations of two differently colored hemispheres. Continue reading “Microspheres for Coatings Applications (Opaque Polyethylene)” »