Session: 16-01-01: Poster Session: NSF-Funded Research (Grad & Undergrad)

Paper Number: 100107

100107 - Kirigami-Inspired Universal Grippers With Programmable Morphology and Trajectory 

Multi-fingered hands of animals are masters of universal grasping, where robotic grippers try to catch up. Countless objects and environments make grasping one of the canonical challenges for robots. State-of-art robotic grippers utilize a variety of methods to tackle this challenge. Powerful rigid grippers utilize a machine learning system or a tight control (force sensing and visual feedback etc.) to perform precise manipulating tasks. Software and hardware complexities are introduced by the inherent uncertainty in the unpredictable reaction of target objects. Compared to traditional rigid robots, soft grippers offer adaptive interactions reducing the risk of harm without feedback control. However, combining the capability of grasping ultra soft, super tiny/thin, and heavy objects is challenging for a gripper or even human hands. Soft grippers have recently emerged as a promising approach for grasping and manipulating miscellaneous objects, using pneumatically or hydraulically driven actuators, underactuated compliant elastomers, and responsive materials. These grippers utilize their morphology to emulate biological motion and adapt to the geometry of targets, facilitating pinching or enveloping. 

Some interesting design strategies are proposed to bridge the gap between adaptivity and reliability, including utilizing suction, the fluid driven rigidity percolation or jamming, and the varied stiffness of responsive materials actuated by electric, temperature, magnetic, humidity, and light stimuli. However, using suction and rigidity percolation requires additional support systems and the response speed of responsive materials is often sacrificed. Moreover, they are not suitable for the nondestructive grasping of gelatinous organisms and liquids. The morphology in state-to-art grippers are only harnessed make them adaptive and the universality is limited. Though there are a few studies targeting on nondestructive grasping ultra-soft organisms, the universal grasping is still problematic. For existing grippers, reliable grasping (robust), minimal invasion (nondestructive), and universality cannot be achieved simultaneously. Here, we demonstrate a soft gripper with universal grasping capability stemming from the programmable morphology and trajectory. The designed structure based on kirigami, a 2D to 3D shape shifting strategy via cut guided deformation, is determined by rationalizing the morphological and mechanical properties through a combination of experiments, finite element simulations, and analytical modeling. Programming the morphology and trajectory of the gripper enables accurate and nondestructive grasping, where we demonstrate the grasping of super-thin, ultra-soft, and other objects. Distinct from the existing universal gripperusing the rigidity percolation of granular systems or shape memory polymers, these nondestructive, accurate, and robust properties in unstructured environments make the gripper de facto universal.

Presenting Author: Yaoye Hong North Carolina State University

Presenting Author Biography: Phd Student from Dr. Jie Yin's group in NCSU

Authors:

Yaoye Hong North Carolina State University
Jie Yin North Carolina State University