arXiv subjects

Wenxiong Hao

Publications and source records attributed to Wenxiong Hao.

2 recordsLinked to original sources

arXiv2023

Fast Swimming Robots Based on Elastic Instability

Inspired by the snap-through action of a steel hairclip, we propose a design method for in-plane prestressed mechanisms that exhibit biomimetic morphing and high locomotion performance. Compliant bistable flapping mechanisms are fabricated using this method and are mounted on our untethered soft robotic fish. Using this mechanism, we achieve life-like undulation with a Strouhal number (1) of St = 0.28 and a velocity of 2.03 body lengths per second (43.6 cm/s), a three-fold improvement over past compliant fish robots. A tethered pneumatic version indicates that this mechanism is compatible with soft actuators. We study the mechanism both computationally and experimentally and suggest that elastic instability may offer a path to overcome the speed challenge of soft and compliant robots.

cs.RO↗

arXiv2023

Pre-stressed Bi-stable Hair Clip Mechanism for Faster Swimming Robots

Structural instability is a hazard that leads to catastrophic failure and is generally avoided through special designs. A trend, however, has emerged over the past decades pointing to the harnessing of mechanisms with instability. Inspired by the snapping of a hair clip, we are finessing the unique characteristics of the lateral-torsional buckling of beams and the snap-through of pre-buckled dome-like thin-wall structures in a new field: the in-plane prestressed mechanism. Analyses reveal how the 2D-3D assembly of an in-plane prestressed actuator (IPA) is achieved and how the post-buckling energy landscape is pictured. Combining them with soft robotics, we show that the inclusion of a bistable IPA can enormously enhance the performance of an underwater fish robot as well as inspire a finger-like soft gripper.

cs.RO↗