Everything about Microspheres
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  • Stainless Steel Microspheres

    300 Series stainless steel is well known for its corrosion resistant properties. Now Scientists are demanding high quality spherical stainless steel microspheres which offer high density (7.8g/cc), high sphericity (>90% round) and corrosion resistance (300 series stainless steel).

    A full range of precision sizes are now available from 1-22um on up to 1.0-1.2mm.

    Stainless Steel 250um (0.25mm) Spheres

    Stainless Steel 250um (0.25mm) Spheres

    Applications for Stainless steel spheres include.
    1) Conductive Spacers
    2) High Density Projectiles
    3) Charge Transport
    4) Shock Absorbtion

    Research vial quantities are listed, many sizes have kg quantities in stock for larger project needs.

  • Deformable Silver Coated PMMA Microsphere Spacers

    Silver Coated Glass Microspheres work well for increasing the conductivity of bond lines, but they lack the capability to deform when compressed to give increased conductive contact between the surfaces of the bond line.  These newly released Silver Coated PMMA Microspheres offer the low weight deformable pmma cores, and 250nm thick silver coating for high conductivity.

    Conductivity of this product has been measured at <0.5ohm per square with a 30% by volume preparation.  Sizes available cover both the common 50 micron (45-53um)  and 100 micron (90-106um) sizes and many others.

    These spheres are perfect for producing anisotropic (only conductive in one direction) conductive bond lines.

    Actual bond line thickness achieved will be a function of the assembly pressure and the size spheres selected.

    In addition to being high conductive these silver coated PMMA is bio-compatible.

  • Reflective Billboard – Creative Outdoor Billboard for McDonald’s

    What a creative alternative to power-hungry digital displays. This large outdoor billboard is totally environmentally friendly because compared to LCD and LED displays that run on electricity, this display takes no energy to run. This creative outdoor billboard is made with reflective tape, visible only when illuminated by headlights in the darkness, created by ad agency Cossette.  To promote a local 24-hour McDonald’s in Canada, Cossette Vancouver designed this reflective billboard that’s only visible at night when cars pass by. By day, the billboard appears blank with no message, but at night, motorists driving along the highway reveal Mickey-D’s clever advertisement with their car headlights. Not only does this display save energy, it can be put anywhere, even in cities with strict requirements on flashing and lit displays.

    Even though this particular display was made using reflective tape, many types of retroreflective media can be made by incorporating retroreflective microspheres in a variety of substances. Retroreflective Microspheres are made by applying a half-shell aluminum coating on solid barium titanate glass microspheres. The spheres hemispherically coated with a thin aluminum shell produce a bright retroreflective response directed back to the light source.

  • Bichromal Janus Particles, Microspheres, Microbeads – Stock selection or Custom-made

    Bichromal (half-white half-black or any other color) Microspheres, Janus Particles

    Bichromal (half-white half-black or any other color) Microspheres, Janus Particles. In this picture - Paramagnetic black microspheres with partial white coating - Magnification 40x.

    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.

    Half-coated glass microspheres - Partial coating on glass particles

    Half-coated glass microspheres - Partial coating on glass particles. In this picture - Soda lime glass microspheres with partial red coating - Magnification 40x.

    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.

    Half-coated Microspheres

    Half-coated Microspheres

    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.

  • Calculating microspheres per gram

    During scientific experiment design and analysis it is common to need to know the number of spheres per gram of dry material.  We have put together the table below to help speed up the process.

    If you have material of a density different from those listed in the table, divide the number of spheres per gram in the density ~1.0 g/cc column by the true particle density of your material to get an estimate of the number of spheres per gram.

    Product Size Polyethylene
    Density ~1.0 (g/cc)
    Soda Lime Glass
    Density ~2.5 (g/cc)
    Lower (um) Upper (um) Spheres per Gram Spheres Per Gram
    20 27 147,162,715 58,630,564
    27 32 74,393,558 29,638,868
    32 45 33,467,185 13,333,540
    45 53 16,233,536 6,467,544
    53 63 9,788,528 3,899,812
    63 75 5,813,720 2,316,223
    75 90 3,401,258 1,355,083
    90 106 2,029,192 808,443
    106 125 1,239,525 493,835
    125 150 734,672 292,698
    150 180 425,157 169,385
    180 212 253,649 101,055
    212 250 154,941 61,729
    250 300 91,834 36,587
    300 355 54,371 21,662
    355 425 32,196 12,827
    425 500 19,305 7,691
    500 600 11,479 4,573
    600 710 6,796 2,708
    710 850 4,025 1,603
    850 1000 2,413 961
    1180 1400 890 354
    1400 1700 513 204
    1700 2000 302 120
    2000 2360 184 73
    2360 2800 111 44
    2800 3350 66 26

    Note: This table assumes the mean diameter is half way between the upper and lower size.