Japanese researchers have made a miniature sculpture of a bull that is the size of a red blood cell. The technology used to produce the bull, the scientists reported in the Aug. 16 issue of Nature, could be used to fabricate so-called nanomachines, miniature devices that could carry out medical procedures in the bloodstream. They have already used the technique to produce a spring and miniature oscillator.
Physicist Satoshi Kawata and his colleagues at Osaka University used two precisely focused lasers aimed at a small drop of plastic resin to outline the bull. The resin hardens only at the intersection of the beams, a process known as two-photon micropolymerization.