Structuring and Shaping of Mechanically Robust and Functional Hydrogels toward Wearable and Implantable Applications

• Published in: Advanced materials (Weinheim) Vol. 36; no. 23; pp. e2309952 - n/a
• Main Authors: Wang, Xiao‐Qiao, Xie, An‐Quan, Cao, Pengle, Yang, Jian, Ong, Wei Li, Zhang, Ke‐Qin, Ho, Ghim Wei
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.06.2024
• Subjects: Automation; Biocompatibility; bioelectronics; Biological materials; biomedical; Biomedical engineering; Hydrogels; Manufacturing engineering; Mechanical engineering; mechanical functions; Polymers; Robotics; Robustness; shaping; soft robots; Softness; Spinning (materials); Three dimensional printing; tough hydrogels; Wearable technology; tough hydrogels; soft robots; biomedical; bioelectronics; shaping; mechanical functions
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.202309952

Hydrogels possess unique features such as softness, wetness, responsiveness, and biocompatibility, making them highly suitable for biointegrated applications that have close interactions with living organisms. However, conventional man‐made hydrogels are usually soft and brittle, making them inferior to the mechanically robust biological hydrogels. To ensure reliable and durable operation of biointegrated wearable and implantable devices, mechanical matching and shape adaptivity of hydrogels to tissues and organs are essential. Recent advances in polymer science and processing technologies have enabled mechanical engineering and shaping of hydrogels for various biointegrated applications. In this review, polymer network structuring strategies at micro/nanoscales for toughening hydrogels are summarized, and representative mechanical functionalities that exist in biological materials but are not easily achieved in synthetic hydrogels are further discussed. Three categories of processing technologies, namely, 3D printing, spinning, and coating for fabrication of tough hydrogel constructs with complex shapes are reviewed, and the corresponding hydrogel toughening strategies are also highlighted. These developments enable adaptive fabrication of mechanically robust and functional hydrogel devices, and promote application of hydrogels in the fields of biomedical engineering, bioelectronics, and soft robotics. The remarkable similarities to living tissues make hydrogels especially suitable for biointegrated applications that closely interact with human bodies. Recent progress in polymer science and advanced processing technologies that enable the mechanical engineering and shaping of hydrogels are reviewed. Moreover, perspectives on further development of mechanically reliable, adaptive biointegrated hydrogel devices for practical use are discussed.