There is experimental need for devices that provide a series of independent dot-stimulation on human skin to simulate tactile perception in order to investigate human somatosensory system, such as somatotopic map. This actuation device requires precise mechanical design to achieve the required mechanical vibration specification and magnetic-field compatibility. After comparing the device structure published in previous studies, we introduce a single-dot-stimulation module including the mechanical structure and control system, which can generate reciprocating motion actuated by bimorph based on the inverse piezoelectric effect. The modules have the potential to be assembled together quickly according to the number of channels required by the tactile stimulation device. To verify the feasibility of the design, we also produced a prototype to test the output characteristics of the module. The results show that the designed module could actuate a carbon fibre rigid string with 0.5mm diameter and 1m long and generate stable 2.6mm displacement output from 0-20 Hz under 200V driving voltage. Finally, we conclude the structure of the single-dot-stimulation module and propose the improvement ideas.