Hollow glass microspheres have been used for years in light-weight filler material, insulation, abrasives and other uses. What makes hollow glass microspheres unique is the network of interconnected pores in the microsphere walls, which allow the tiny "microballoons" to be filled with, hold, and release gases and other materials.
Each porous walled hollow glass microsphere is about 50 microns in diameter, about half the width of a human hair. Its walls, which are about 10,000 angstroms thick (an angstrom is one-tenth of one-billionth of a meter) feature pores that range from 100 to 300 angstroms, which allow gases to enter the tiny spheres and be stored or cycled on absorbents inside.
Work since then has shown potential in other uses, including battery applications and medicine. Hollow glass microsphere have been discussed a possible application for the delivery of anti-cancer drugs. Porous-wall hollow glass microspheres as novel potential nanocarriers for biomedical applications.