Multifunctional Soft Stackable Robots by Netting-Rolling-Splicing Pneumatic Artificial Muscles

Weaving liquid crystal elastomer fiber actuators for multifunctional soft robotics

Inspired by the remarkable adaptability observed in biological organisms, multifunctional soft robotics have emerged as promising systems capable of navigating complex environments. In this study, we present a strategy for weaving fiber soft actuators to overcome the existing limitations in deformation capabilities and complex manufacturing processes. This strategy combines traditional rope artistry with the advanced responsive characteristics of electro-driven liquid crystal elastomer (LCE) fibers, facilitating the efficient creation of multifunctional soft actuators. Leveraging this strategy, we have developed four distinct types of soft actuators: the double twisting weaving actuator (DTWA), the circular four-strand weaving actuator (CFWA), the orthogonal weaving actuator (OWA), and the diagonal weaving actuator (DWA). These weaving fiber soft actuators can be readily assembled in various soft robots, granting multiple functionalities, including surface shape programmability, biomimetic blood pumping inspired by the cardiac muscle, and versatile locomotion modes such as crawling and swimming. Our proposed strategy offers unprecedented opportunities for multifunctional soft robots in performing complex tasks.

Soft Actuator with Biomass Porous Electrode: A Strategy for Lowering Voltage and Enhancing Durability

Electroactive artificial muscles with deformability have attracted widespread interest in the field of soft robotics. However, the design of artificial muscles with low-driven voltage and operational durability remains challenging. Herein, novel biomass porous carbon (BPC) electrodes are proposed. The nanoporous BPC enables the electrode to provide exposed active surfaces for charge transfer and unimpeded channels for ion migration, thus decreasing the driving voltage, enhancing time durability, and maintaining the actuation performances simultaneously. The proposed actuator exhibits a high displacement of 13.6 mm (bending strain of 0.54%) under 0.5 V and long-term durability of 99.3% retention after 550,000 cycles (∼13 days) without breaks. Further, the actuators are integrated to perform soft touch on a smartphone and demonstrated as bioinspired robots, including a bionic butterfly and a crawling robot (moving speed = 0.08 BL s-1). This strategy provides new insight into the design and fabrication of high-performance electroactive soft actuators with great application potential.

Variable stiffness soft robotic gripper: design, development, and prospects

The advent of variable stiffness soft robotic grippers furnishes a conduit for exploration and manipulation within uncharted, non-structured environments. The paper provides a comprehensive review of the necessary technologies for the configuration design of soft robotic grippers with variable stiffness, serving as a reference for innovative gripper design. The design of variable stiffness soft robotic grippers typically encompasses the design of soft robotic grippers and variable stiffness modules. To adapt to unfamiliar environments and grasp unknown objects, a categorization and discussion have been undertaken based on the contact and motion manifestations between the gripper and the things across various dimensions: points contact, lines contact, surfaces contact, and full-bodies contact, elucidating the advantages and characteristics of each gripping type. Furthermore, when designing soft robotic grippers, we must consider the effectiveness of object grasping methods but also the applicability of the actuation in the target environment. The actuation is the propelling force behind the gripping motion, holding utmost significance in shaping the structure of the gripper. Given the challenge of matching the actuation of robotic grippers with the target scenario, we reviewed the actuation of soft robotic grippers. We analyzed the strengths and limitations of various soft actuation, providing insights into the actuation design for soft robotic grippers. As a crucial technique for variable stiffness soft robotic grippers, variable stiffness technology can effectively address issues such as poor load-bearing capacity and instability caused by the softness of materials. Through a retrospective analysis of variable stiffness theory, we comprehensively introduce the development of variable stiffness theory in soft robotic grippers and showcase the application of variable stiffness grasping technology through specific case studies. Finally, we discuss the future prospects of variable stiffness grasping robots from several perspectives of applications and technologies.