Efficient and reliable external mechanical actuation is one of the key factors for a successful magnetic resonance elastography (MRE). Existing actuators just attaches to the surface of human tissues and only unidirectional force is applied. A new adsorption actuator is proposed in this study to cope with this problem. It adsorbs soft tissue by creating a vacuum environment between the actuator and the tissue, and they are thereby coupled together during MRE actuation. In the experiments the new actuator performs better with more harmonic vibration, and the driving efficiency was enhanced substantially, too. Different numerical models based on collision hypothesis discover the working principle of the actuator.