Inflatable Kirigami Crawlers

TL;DR

This paper introduces inflatable kirigami crawlers made from heat-sealable textiles that achieve controlled locomotion through cyclic pneumatic actuation, leveraging geometric nonlinearities for directional movement and surface adaptability.

Contribution

It presents a novel inflatable kirigami design with engineered cut patterns that enable predictable, directional locomotion and surface interaction in soft robotic crawlers.

Findings

Inflatable kirigami actuators show asymmetric out-of-plane deformations.

They exhibit directional anisotropic friction properties.

Multiple channels enable versatile locomotion capabilities.

Abstract

Kirigami offers unique opportunities for guided morphing by leveraging the geometry of the cuts. This work presents inflatable kirigami crawlers created by introducing cut patterns into heat-sealable textiles to achieve locomotion upon cyclic pneumatic actuation. Inflating traditional air pouches results in symmetric bulging and contraction. In inflated kirigami actuators, the accumulated compressive forces uniformly break the symmetry, enhance contraction compared to simple air pouches by two folds, and trigger local rotation of the sealed edges that overlap and self-assemble into an architected surface with emerging scale-like features. As a result, the inflatable kirigami actuators exhibit a uniform, controlled contraction with asymmetric localized out-of-plane deformations. This process allows us to harness the geometric and material nonlinearities to imbue inflatable textile-based kirigami actuators with predictable locomotive functionalities. We thoroughly characterized the programmed deformations of these actuators and their impact on friction. We found that the kirigami actuators exhibit directional anisotropic friction properties when inflated, having higher friction coefficients against the direction of the movement, enabling them to move across surfaces with varying roughness. We further enhanced the functionality of inflatable kirigami actuators by introducing multiple channels and segments to create functional soft robotic prototypes with versatile locomotion capabilities.