A flow of liquid containing floating fine particles is formed in a flow path, thereby causing successive movement of the particles. A light beam having intensity distribution from a laser is focused on the liquid flow, whereby the particle is optically trapped at the irradiating position, thus being...http://www.google.com/patents/US5495105?utm_source=gb-gplus-sharePatent US5495105 - Method and apparatus for particle manipulation, and measuring apparatus utilizing the same
