A recent article on microspheres in Cosmetics & Toiletries magazine describes the use Solid Polyethylene Mirospheres for Effects in Color Cosmetics.
Microspheres have been used in cosmetics for some time, primarily as fillers and exfoliators. Most recently scientists started to utilize light reflecting properties of microspheres for creating unique optical effects, such as optical blurring and wrinkle filling. Due to light scattering effects of the spherical surface, formulating with appropriate microspheres can minimize the appearance of fine lines and uneven skin tone, due to optically reducing contrast on the skin.
The spherical shape and smooth surface of microspheres creates a low friction ball-bearing effect that gives formulations an elegant, silky feel. This ball-bearing effect promotes better blending on the skin and a more natural finish due to the enhanced slip, glide and omnidirectional spreadability, imparting a cream to powder texture. Outstanding roundness also provides lubrication during application, which enhances the tactile experience of a cosmetic product.
Colored microspheres can be used to replace the pigment in the formulation while adding the sensorial benefits of smoothness and spreadability. Controlling the electrostatic charge of the microspheres and specific gravity enables the formulators to achieve a stable dispersion of microspheres in solution and control the interaction of microspheres with the skin.
To create microspheres with a positive or negative charge, proprietary additives are embedded into each microsphere during the manufacturing process. This charge is permanent; it does not dissipate over time and cannot be grounded. The whole microsphere is charged and will respond to electric field. Further, dark-colored or black microspheres can be made magnetic or static-dissipative, and a black magnetic coating on a portion of the microsphere can be used to create functionalized hemispheres, i.e., magnetic half-shells that can be manipulated to rotate microspheres with an electromagnetic field.