Multimodal Limbless Crawling Soft Robot with a Kirigami Skin

2025-05-12

Cyborg and Bionic Systems

AI Summary

To address the challenge of efficient locomotion for limbless soft robots on complex, unstructured terrain, this work proposes a bioinspired design leveraging body-deformation–ground-microasperity interaction. The robot integrates a novel kirigami-based heterogeneous frictional skin with antagonistic pneumatic soft actuators within a single monolithic structure, enabling dual-gait switching—namely, forward crawling, in-place rotation, and large-angle asymmetric turning—under phase-modulated pneumatic actuation. Coupled with onboard short-range sensing and adaptive human–robot interaction control, the system supports autonomous obstacle avoidance and navigation. Experimental results demonstrate stable operation across coarse-grained substrates and multi-obstacle environments, significantly enhancing locomotive robustness and environmental adaptability. This approach advances soft robotics for real-world applications such as search-and-rescue and infrastructure inspection.

Technology Category

• Intelligent Robots: Multimodal Perception & Sensor Fusion
• Machine Learning: Bio-inspired Learning
• Search and Optimization: Sampling/Simulation-based Search

Application Category

• Search and Retrieval-Augmented AI: Assisted, interactive, and conversational search
• Responsible Web: Machine-in-the-loop, human agency and autonomy
• Systems and Infrastructure for Web, Mobile and WoT: Experiences and lessons learnt from Web-based algorithms and system deployments

Abstract

Limbless creatures can crawl on flat surfaces by deforming their bodies and interacting with asperities on the ground, offering a biological blueprint for designing efficient limbless robots. Inspired by this natural locomotion, we present a soft robot capable of navigating complex terrains using a combination of rectilinear motion and asymmetric steering gaits. The robot is made of a pair of antagonistic inflatable soft actuators covered with a flexible kirigami skin with asymmetric frictional properties. The robot's rectilinear locomotion is achieved through cyclic inflation of internal chambers with precise phase shifts, enabling forward progression. Steering is accomplished using an asymmetric gait, allowing for both in-place rotation and wide turns. To validate its mobility in obstacle-rich environments, we tested the robot in an arena with coarse substrates and multiple obstacles. Real-time feedback from onboard proximity sensors, integrated with a human-machine interface (HMI), allowed adaptive control to avoid collisions. This study highlights the potential of bioinspired soft robots for applications in confined or unstructured environments, such as search-and-rescue operations, environmental monitoring, and industrial inspections.

Problem

• Designing bioinspired limbless soft robots for complex terrains
• Achieving locomotion via inflatable actuators and kirigami skin
• Enabling adaptive control for obstacle-rich environments

Innovation

• Soft robot with kirigami skin for crawling
• Antagonistic inflatable actuators enable locomotion
• Onboard sensors with HMI for adaptive control