Femtosecond laser programmed artificial musculoskeletal systems

• Published in: Nature communications Vol. 11; no. 1; pp. 4536 - 10
• Main Authors: Ma, Zhuo-Chen, Zhang, Yong-Lai, Han, Bing, Hu, Xin-Yu, Li, Chun-He, Chen, Qi-Dai, Sun, Hong-Bo
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 10.09.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 140/125; 147/135; 639/301/357/551; 639/301/923/1027; 639/638/298/923/1027; Biomimetics - instrumentation; Biomimetics - methods; Bovine serum albumin; Configurations; Epoxy Compounds - chemistry; Epoxy Compounds - radiation effects; Humanities and Social Sciences; Hydrogels - chemistry; Hydrogels - radiation effects; Hydrogen-Ion Concentration; Lasers; Microbots; Microrobots; multidisciplinary; Muscles; Musculoskeletal Physiological Phenomena; pH effects; Photosensitivity; Polymerization - radiation effects; Polymers - chemistry; Polymers - radiation effects; Printing, Three-Dimensional; Proteins; Prototyping; Robotics - instrumentation; Robotics - methods; Robustness; Science; Science (multidisciplinary); Serum albumin; Serum Albumin, Bovine - chemistry; Serum Albumin, Bovine - radiation effects; Three dimensional printing
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-18117-0

Natural musculoskeletal systems have been widely recognized as an advanced robotic model for designing robust yet flexible microbots. However, the development of artificial musculoskeletal systems at micro-nanoscale currently remains a big challenge, since it requires precise assembly of two or more materials of distinct properties into complex 3D micro/nanostructures. In this study, we report femtosecond laser programmed artificial musculoskeletal systems for prototyping 3D microbots, using relatively stiff SU-8 as the skeleton and pH-responsive protein (bovine serum albumin, BSA) as the smart muscle. To realize the programmable integration of the two materials into a 3D configuration, a successive on-chip two-photon polymerization (TPP) strategy that enables structuring two photosensitive materials sequentially within a predesigned configuration was proposed. As a proof-of-concept, we demonstrate a pH-responsive spider microbot and a 3D smart micro-gripper that enables controllable grabbing and releasing. Our strategy provides a universal protocol for directly printing 3D microbots composed of multiple materials. Musculoskeletal systems are recognized as a model for designing robust yet flexible microbots but the development of artificial musculoskeletal systems at nanoscale currently remains challenging. Here the authors report a laser programmed artificial musculoskeletal systems for prototyping 3D microbots, using relatively stiff SU-8 as the skeleton and pH-responsive proteins as the smart muscle.