Photomechanical bending of 4-aminoazobenzene crystals

Upon photoirradiation at 365 nm, platelike microcrystals of trans-4-aminoazobenzene quickly bend away from the light source, returning to their initial linear shape when irradiation was terminated. However, relative to the observations upon cessation of 365 nm irradiation, the bent crystals recovered their initial shape more rapidly when exposed to visible light (530 nm) irradiation.

► Photomechanical bending of crystals is reported.
► Platelike microcrystals of trans-4-aminoazobenzene quickly bend away from the light source upon photoirradiation at 365 nm.
► The bent crystals recover their initial shape more rapidly when exposed to visible light (530 nm) irradiation instead of the thermal process.