摘要： Optical tweezers have endured as an invaluable laboratory tool for manipulating molecules and other small particles. In 1619 Johannes Kepler proposed that solar radiation pressure, along with solar wind, might explain the observation that a comet’s tail always points away from the Sun. His book De cometis libelli tres presented the earliest recorded conjecture that light had momentum. Two centuries later James Clerk Maxwell’s energy-balance calculations formalized the idea that electromagnetic radiation can indeed exert a force upon a surface. Following the advent of the laser in the 1960s, Arthur Ashkin was one of the first people to explore the possibility of harnessing radiation pressure to manipulate particles with a focused beam of photons. Only in astronomy, where the net effect of a tiny force could have a large cumulative effect over time, had physicists thought that radiation pressure may be significant. Ashkin, then a researcher at AT&T Bell Labs in Holmdel, New Jersey, wondered whether “one could see observable motion from light pressure forces on particles in the laboratory, using the high intensities of focused laser beams.” That question led him to develop a technique that used a laser to hold and manipulate dielectric particles. Communities of researchers in soft matter, biophysics, atomic physics, and photonics have adopted Ashkin’s “optical tweezers” to propel or trap microparticles and to investigate biology at the single-molecule level. Half of the 2018 Nobel Prize in Physics honored Ashkin “for the optical tweezers and their application to biological systems.”