Variable-Grasping-Mode Gripper With Different Finger Structures For Grasping Small-Sized Items

TL;DR

This paper introduces a versatile small gripper with two grasping modes, enabling effective handling of tiny, lightweight items for small device assembly, using a single actuator and contact-based mode switching.

Contribution

A novel small gripper with switchable parallel and turn-over modes, capable of grasping very thin and lightweight objects with a single actuator.

Findings

Successfully grasped items as thin as 0.05 mm

Handled lightweight objects weighing 0.007 g

Demonstrated effective mode switching via contact with a surface

Abstract

This letter presents a novel small gripper capable of grasping various types of small-sized items from flat surfaces for the assembly of small devices. Using a single actuator, the proposed gripper realizes two grasping modes: parallel-grip and turn-over modes. The gripper's mode can be switched via contact with a flat surface, such as a table. Handling thin thicknesses and light weights are the key challenges faced in attempts to grasp small-sized items. Although parallel grippers are effective in handling small items, there is a limit to the thinness of objects that can be grasped by parallel grippers. Accordingly, the turn-over mode was adopted to grasp items that exceeded this threshold. In the turn-over mode, one finger lifts the item, while another finger holds the item from above to keep it from flicking out. The proposed gripper is capable of picking up several types of items from a table, including thin (0.05 mm) and lightweight (0.007 g) items.