The capability of inchworm motor for long-displacement, heavy-load and precise positioning is greatly conditioned by the effectiveness of the clamping mechanism. A need exists in the art for clamping mechanism capable of delivering precise and heavy load motion. This paper presents a novel giant magnetostriction material (GMM) application to the development of such mechanism. GMM is advantageous over other smart materials in this particular aspect by its remarkable magnetostriction and especially the huge blocked stress. It can, e.g., display around 4000N at moderate magnetization with a φ25×100mm GMM rod. Most desirably, such large force could be used as clamping force in inchworm movement. However, the force can only be generated under blocked state, which is generally hard to reach, especially in a moving regime. Addressing this problem, the research utilizes GMM rod’s capacity to both positively stretch and negatively contract under permanent-magnet-biased condition and presents a specially designed clamping mechanism, a permanent-magnet-biased actuator fastened in a rigid guideway. Being applied reverse magnetic field, the formerly stretched actuator may contract to a suitable size to be put into the rigid guideway. Then, removal of the field will theoretically result in the restoration of the actuator. Practically, stretching of the actuator is blocked by the rigid guideway. This forms the so-called Pre-blocked-clamping-on state, where no-power fastening behavior exists. Moreover, the blocked force is adjustable. When being applied the same-direction field as the permanent one, the blocked force becomes greater (Blocked-clamping-on state). When being applied adequate reverse field, the blocked force is diminished with the shrinking of the actuator, till the actuator released from the rails (Blocked-clamping-off state). This process realizes the utilization of blocked force in clamping action, thus provides resolution for secure and heavy load inchworm motion. A clamping mechanism prototype (Size:φ32×130mm, with a φ10×100mm GMM rod) has been realized. The design and working process of the setup is presented. Through experiments, the prototype can be facilely manipulated by square-instant and sinusoid-continuing current and it can agilely perform to meet the proposed blocked force the proposed clamping principle.

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