Silicon Nanospheres Rank Among Hardest Known Materials
University of Minnesota researchers have made the first-ever hardness measurements on individual silicon nanospheres and shown that the nanospheres’ hardness falls between the conventional hardness of sapphire and diamond, which are among the hardest known materials. Being able to measure such nanoparticle properties may eventually help scientists design low-cost superhard materials from these nanoscale building blocks. Up to four times harder than typical silicon — a principal ingredient of computer chips, glass and sand — the nanospheres demonstrate that other materials at the nanoscale, including sapphire, may also have vastly improved mechanical properties.