　　　Piezoelectric crystals are useful in industrial and consumer applications because of their special characteristic: they can be bent by electricity. But, the crystals require wire connection so the electricity can be supplied. Wire connection prevents their use in water and size-reduction to micrometer-scale. Here, we report on wireless molecular-crystal actuators, which work upon photoirradiation. Rod-like mixed crystals of 1-(5-methyl-2-phenyl-4-thiazolyl)-2-(5-methyl-2-p-tolyl-4-thiazolyl)perfluoro-cyclopentene (1a) and 1,2-(5-methyl-2-p-tolyl-4-thiazolyl)- perfluorocyclopentene (2a) with size ranging from micrometer to mm were found to exhibit rapid (response time < 5 microseconds), reversible and fatigue resistant bending over 1,000 cycles upon alternate irradiation with UV (365 nm) and visible (> 500 nm) light. The rod-like crystal readily bends toward the UV light source and even curls into a hairpin shape. In situ X-ray crystallographic analysis revealed that the shrinkage of b-axis of the crystal, which corresponds to the long axis of the rod-like crystal, causes the bending and curling. The crystal performs the mechanical motion even in water and has extremely wide range of working temperature (4.6 K < T < 370 K). The photogenerated maximum stress was estimated to be 56 MPa, which is comparable to that of piezoelectric crystals.