Thin photo-thermal sensitive hydrogel film on elastic substrate has been widely used in the fields of micromechanics system (MEMS)

biosensors and actuators. Due to the confinement of the elastic substrate

when the photo-thermally sensitive hydrogel swelling with the change of external temperature or light intensity

the existence of the compressive stress in the hydrogel film makes the film wrinkle. Based on the finite deformation theory of the photo-thermally sensitive hydrogel and von Karman nonlinear plate theory

this paper studied the wrinkling mechanism of the photo-thermally sensitive hydrogel film and analyzed the effects of light intensity

temperature

chemical potential of the solvent and the stiffness coefficient of the substrate on the critical wavelength and critical stress of wrinkling of photo-thermally sensitive hydrogel film. The results show that: when the temperature and light intensity keep the same

the critical stress decreases with increasing chemical potential of the solution; when the chemical potential keeps the same

the higher the light intensity and temperature

the greater the critical stress; when the light intensity and the temperature keep the same

the smaller the stiffness coefficient

the greater the critical wavelength; for the same stiffness coefficient

the lower light intensity and the temperature

the smaller the critical wavelength.