Flexible Torsional Photoactuators Based on MXene-Carbon Nanotube-Paraffin Wax Films

Bionic learning in MXene-based actuators: An emerging frontier

Bionics offers valuable insights into the design and application of MXene-based soft actuators, which have garnered significant attention in the fields of flexible electronics and smart materials owing to their exceptional electrical conductivity, tunable interlayer spacing, and responsiveness to diverse external stimuli. This review begins with a comprehensive summary of the main response mechanisms of MXene-based soft actuators under various external stimuli. It presents a detailed analysis of the advantages and limitations of different actuation modes and discusses strategies for composite modification with other materials to enhance MXene performance under multi-stimulus conditions. Inspired by the sensory capabilities of animals and plants in nature, this work explores the potential for biomimetic design and identifies four key challenges for advancing the field: (1) the development of efficient and controllable material synthesis techniques, (2) the electrochemical stability and environmental robustness of devices, (3) the overall performance optimization of actuators, and (4) the nascent exploration of biomimetic learning mechanisms. Finally, future research directions are outlined, offering novel perspectives to promote the broader application of MXene-based soft actuators in biomimetic systems.

From Coils to Crawls: A Snake-Inspired Soft Robot for Multimodal Locomotion and Grasping

Currently, numerous biomimetic robots inspired by natural biological systems have been developed. However, creating soft robots with versatile locomotion modes remains a significant challenge. Snakes, as invertebrate reptiles, exhibit diverse and powerful locomotion abilities, including prey constriction, sidewinding, accordion locomotion, and winding climbing, making them a focus of robotics research. In this study, we present a snake-inspired soft robot with an initial coiling structure, fabricated using MXene-cellulose nanofiber ink printed on pre-expanded polyethylene film through direct ink writing technology. The controllable fabrication of initial coiling structure soft robot (ICSBot) has been achieved through theoretical calculations and finite element analysis to predict and analyze the initial structure of ICSBot, and programmable ICSBot has been designed and fabricated. This robot functions as a coiling gripper capable of grasping objects with complex shapes under near infrared light stimulation. Additionally, it demonstrates multi-modal crawling locomotion in various environments, including confined spaces, unstructured terrains, and both inside and outside tubes. These results offer a novel strategy for designing and fabricating coiling-structured soft robots and highlight their potential applications in smart and multifunctional robotics.

Untethered Soft Robots Based on 1D and 2D Nanomaterials

Biological structures exhibit autonomous and intelligent behaviors, such as movement, perception, and responses to environmental changes, through dynamic interactions with their surroundings. Inspired by natural organisms, future soft robots are also advancing toward autonomy, sustainability, and interactivity. This review summarizes the latest achievements in untethered soft robots based on 1D and 2D nanomaterials. First, the performance of soft actuators designed with different structures is compared. Then, the development of basic locomotion forms, including crawling, jumping, swimming, rolling, gripping, and multimodal, mimicking biological motion mechanisms under dynamic stimuli, is discussed. Subsequently, various self-sustained movements based on imbalance mechanisms under static stimuli are introduced, including light tracking, self-oscillating, self-crawling, self-rolling, and flying. Following that, the progress in soft actuators integrated with additional functionalities such as sensing, energy harvesting, and storage is summarized. Finally, the challenges faced in this field and the prospects for future development are discussed.

Optomagnetic Coordination Helical Robot with Shape Transformation and Multimodal Motion Capabilities

Soft robots with magnetic responsiveness exhibit diverse motion modes and programmable shape transformations. While the fixed magnetization configuration facilitates coupling control of robot posture and motion, it limits individual posture control to some extent. This poses a challenge in independently controlling the robot's transformation and motion, restricting its versatile applications. This research introduces a multifunctional helical robot responsive to both light and magnetism, segregating posture control from movements. Light fields assist in robot shaping, achieving a 78% maximum diameter shift. Magnetic fields guide helical robots in multimodal motions, encompassing rotation, flipping, rolling, and spinning-induced propulsion. By controlling multimodal locomotion and shape transformation on demand, helical robots gain enhanced flexibility. This innovation allows them to tightly grip and wirelessly transport designated payloads, showcasing potential applications in drug delivery, soft grippers, and chemical reaction platforms. The unique combination of structural design and control methods holds promise for intelligent robots in the future.