A Novel Dual-Probe-Based Micrograsping System Allowing Dexterous 3-D Orientation Adjustment.

This article proposes a two-finger-based micrograsping system with high compliant borosilicate 3.3 glass probes and the corresponding sensing and control algorithms, which enables the orientation manipulation of microparts in three-dimensional (3-D) space. Compared with the existing research, the novelty of this article relies on three aspects: 1) the end-effector of the microgripper is designed to be with high compliance so that the squeeze force exerted on microparts can be more accurately regulated and the proposed microgripper is capable of manipulating fragile microparts; 2) the micrograsping system is endowed the capability to fully manipulate microparts’ orientation without recurring to auxiliary probes or rotary stages; and 3) the vibration characteristic of the grasping arm is investigated as cantilever beam for gasping stability analysis and squeeze force maintaining. In specific, taking spherical microparts with dimensions in the range from tens to hundreds of micrometers as target, the grasping system configuration, and the contact model between the probe and the microparts are first presented. Afterward, kinematics-based motion control strategy for position adjustment and orientation manipulation of microparts is clarified. Then, squeeze force regulation strategy is proposed, including adhesive force evaluation, vision-based squeeze force estimation, and the micropart releasing method. Finally, the vibration characteristic of the grasping arm is investigated as cantilever beam for gasping stability analysis and the squeeze force maintaining. The reliability and availability of the proposed micrograsping system is validated by well-designed experiments. Note to Practitioners—This article is motivated to develop a micrograsping system which enables dexterous rotating manipulation of microparts. The core of the proposed system is the utility of two fistulous tampered borosilicate 3.3 glass probes, which show high compliance in the microdomain. The manifested compliance enables the stably grasping of spherical objects during dexterous rotating manipulation and the vision-based contact force evaluation and regulation. The proposed system can rotate objects about two independent axes so that the orientation of a micropart can be adjusted to the desired one. This is critically important for many practical applications, such as the assembly of microballon and microneedle and the beamed cell penetration. [ABSTRACT FROM AUTHOR]