Search for: All records

Abstract Navigating in three‐dimensional (3D) environments with precise motion control is challenging for soft robots due to their inherent flexibility. Inspired by aerial trams, here, an autonomous soft twisted ring robot is reported capable of navigating pre‐defined tracks in 3D space under constant photothermal actuation, without requiring spatiotemporal control of actuation sources. Made of liquid crystal elastomers, the ring robot, suspended on thread‐based tracks, self‐flips around its centerline when exposed to constant infrared light. Curling the twisted ring around tracks converts its self‐rotary motion into autonomous linear movement via screw theory. This mechanism enables the autonomous robot to adapt to tracks of various materials and micron‐to‐millimeter sizes, overcome obstacles like knots on tracks, transport loads over 12 times its weight, ascend and descend steep slopes up to 80°, and navigate complex paths, including circular, polygonal, and 3D spiral tracks, as well as loose threads with dynamically changing shapes. 

Abstract Miniature shape‐morphing soft actuators driven by external stimuli and fluidic pressure hold great promise in morphing matter and small‐scale soft robotics. However, it remains challenging to achieve both rich shape morphing and shape locking in a fast and controlled way due to the limitations of actuation reversibility and fabrication. Here, fully 3D‐printed, sub‐millimeter thin‐plate‐like miniature soft hydraulic actuators with shape memory effect (SME) for programable fast shape morphing and shape locking, are reported. It combines commercial high‐resolution multi‐material 3D printing of stiff shape memory polymers (SMPs) and soft elastomers and direct printing of microfluidic channels and 2D/3D channel networks embedded in elastomers in a single print run. Leveraging spatial patterning of hybrid compositions and expansion heterogeneity of microfluidic channel networks for versatile hydraulically actuated shape morphing, including circular, wavy, helical, saddle, and warping shapes with various curvatures, are demonstrated. The morphed shapes can be temporarily locked and recover to their original planar forms repeatedly by activating SME of the SMPs. Utilizing the fast shape morphing and locking in the miniature actuators, their potential applications in non‐invasive manipulation of small‐scale objects and fragile living organisms, multimodal entanglement grasping, and energy‐saving manipulators, are demonstrated. 

Shape-shifting structures can transform and recover their shapes in response to external stimuli, but they often lack programmable, clock-like control over spatiotemporal deformation and motion, especially after stimuli are removed. Achieving autonomous, time-regulated spatiotemporal motion remains a grand challenge. Here, we present an autonomous delayed-jumping metashell that integrates viscoelastic materials with monostable architected structures to address this limitation. The metashell with tunable prestored elastic energy features an internal time clock enabling programmable autonomous delayed snapping and jumping after actuation removal. The delay spans from seconds to 2.4 d, with jumping heights decreasing from over 9 to 0.5 body heights. We demonstrate its utility in autonomous explosive seed dispersal devices, achieving wide-area omnidirectional distribution with high survival rates. This strategy paves the way for creating autonomous spatiotemporal shape-shifting structures with broad applications in robotics, morphing matter, ecology, and intelligent systems. 

Manta rays use wing-like pectoral fins for intriguing oscillatory swimming. It provides rich inspiration for designing potentially fast, efficient, and maneuverable soft swimming robots, which, however, have yet to be realized. It remains a grand challenge to combine fast speed, high efficiency, and high maneuverability in a single soft swimmer while using simple actuation and control. Here, we report leveraging spontaneous snapping stroke in the monostable flapping wing of a manta-like soft swimmer to address the challenge. The monostable wing is pneumatically actuated to instantaneously snap through to stroke down, and upon deflation, it will spontaneously stroke up by snapping back to its initial state, driven by elastic restoring force, without consuming additional energy. This largely simplifies designs, actuation, and control for achieving a record-high speed of 6.8 body length per second, high energy efficiency, and high maneuverability and collision resilience in navigating through underwater unstructured environments with obstacles by simply tuning single-input actuation frequencies. 

Soft shape-shifting materials offer enhanced adaptability in shape-governed properties and functionalities. However, once morphed, they struggle to reprogram their shapes and simultaneously bear loads for fulfilling multifunctionalities. Here, we report a dynamic spatiotemporal shape-shifting kirigami dome metasheet with high deformability and stiffness that responds rapidly to dynamically changing magnetic fields. The magnetic kirigami dome exhibits over twice higher doming height and 1.5 times larger bending curvature, as well as sevenfold enhanced structural stiffness compared to its continuous counterpart without cuts. The metasheet achieves omnidirectional doming and multimodal translational and rotational wave-like shape-shifting, quickly responding to changing magnetic fields within 2 milliseconds. Using the dynamic shape-shifting and adaptive interactions with objects, we demonstrate its applications in voxelated dynamic displays and remote magnetic multimodal directional and rotary manipulation of nonmagnetic objects without grasping. It shows high-load transportation ability of over 40 times its own weight, as well as versatility in handling objects of different materials (liquid and solid), sizes, shapes, and weights.