A four degree of freedom MEMS microgripper with novel bi-directional thermal actuators

A four degree of freedom thermally actuated MEMS microgripper is presented in this paper. Each jaw of the microgripper has independent x and y degrees of freedom. These extra degrees of freedom give the gripper added dexterity for manipulating microparts. The motion of each gripper jaw is provided by a two degree of freedom compliant mechanism which is based on a five bar rigid link mechanism. This gripper also introduces a novel thermal microactuator design that is capable of bi-directional actuation giving it a greater range of motion than previous thermal actuator designs. The actuator provides a total range of motion of 12.7 μm and a maximum force of 1.9 mN. Also, since this microgripper is based on a compliant mechanism, deformable object tracking can be used to provide force as well as position feedback for the gripper. This combination of an increased number of degrees of freedom and increased sensory feedback provides a level of dexterity that has not been previously available in microassembly.