无需预载，单步成型！华南理工“大节距”人造肌肉登权威期刊，软体机器人驱动迎来巨变

Core Viewpoint - The article discusses a significant breakthrough in soft robotics, specifically in the development of artificial muscles that exhibit remarkable performance characteristics, including a contraction of 95.1% and an extension of 560%, surpassing the power density of cheetah muscles by 35 times [1][10][17]. Group 1: Technical Breakthroughs - The development of soft robots has faced a core contradiction between flexibility and load-bearing capacity, leading to the exploration of twisted helical polymer artificial muscles as a potential solution [2][3]. - A new method called "self-induced large helical pitch (SLiP)" has been proposed, allowing for programmable large deformation and high load capabilities without the need for preloading [5][6]. - The manufacturing process involves a simple adjustment of annealing temperature and time, enabling the creation of SLiP muscles with controllable large pitches in a single thermal treatment [8][10]. Group 2: Performance Metrics - SLiP muscles can achieve a maximum contraction strain of 95.1% under load, meaning a 1 cm long muscle can shrink to less than 0.5 cm [11][13]. - In a free state, the contraction rate reaches 86.6%, demonstrating the core advantage of achieving large deformation without preloading [13]. - The muscles can also achieve an impressive extension of 560% when designed with specific helical configurations, showcasing their potential for robotic applications [15][17]. Group 3: Stability and Reliability - SLiP muscles have shown excellent stability and reliability, with performance fluctuations below 1% over 5000 heating-cooling cycles, indicating their suitability for practical applications [19][21]. - The manufacturing process effectively releases internal stresses in the fibers, maintaining structural stability under repeated thermal-mechanical loads [21][22]. Group 4: Practical Applications - The research team has developed various prototypes, including a bionic robotic arm that can smoothly rotate 72.5° while carrying a 10-gram load, mimicking human arm movements [23][25]. - A soft crawling robot inspired by the inchworm demonstrated a foot length change rate of 41.6%, showcasing the large deformation capabilities of SLiP muscles [25][27]. - A soft tentacle driven by SLiP muscles achieved a bending angle of 256°, exhibiting adaptability in grasping various objects [27][30]. Group 5: Future Challenges - The formation of the helical pitch relies on the thermal relaxation and molecular rearrangement of semi-crystalline fibers, which may limit the range of materials that can be effectively processed [34]. - The design for high strain may reduce muscle stiffness, posing challenges for high-load applications [35]. - Long-term thermal cycling could introduce slow viscoelastic geometric changes in polymer materials, necessitating further investigation into long-term stability under harsher conditions [36].