Low-Frequency Vibration Actuator Using a DC Motor

In our previous study, we found that a normal DC motor can be used for vibro-tactile and pseudo-force presentation. In the present study, we developed a new vibration actuator using a DC motor that can generate much stronger vibrations than a normal DC motor and produce very low frequency of vibrations. We proposed that the stator of the motor could be used as both the vibration mass and fixed rotor of the actuator. To evaluate this design concept, we developed a prototype actuator that can be driven in two modes: stator mode (i.e., the new design concept) and normal mode. The experiment results revealed that stronger vibrations can be obtained on a fingertip in stator mode because the fixed part that comprises the rotor was lighter and the vibration mass using the stator was heavier. We also confirmed that the actuator can be driven at very low frequency (1 Hz) in stator mode.