Abstract: The tactile sensor of the present disclosure is an indirect optical sensor, comprising a frame, a sensing plate, a single beam LED light source, a miniature camera, and a grating plate in the sensing plate and the single light source illuminates the grating plate. Geometric interference fringes caused by the shadows of gratings and gratings, images taken by a miniature camera, through an innovative instantaneous steps phase shifting technique, which eliminates the need for any mechanical phase shifting device to detect the pressure and space. The position is measured and has fast and accurate tactile sensing. The advantage of this method is that directly shooting the moiré image while calculating the spatial position, temperature, and pressure. Instantaneous steps phase shifting technique can solve the problems of traditional mechanical stepping, non-instant and complex operation problems.