Self-Healing Hydrogels

• Published in: Advanced materials (Weinheim) 2016-11, Vol.28 (41), p.9060-9093
• Main Authors: Taylor, Danielle Lynne, in het Panhuis, Marc
• Format: Article
• Language: English
• Subjects: Actuators; autonomous; Efficiency; Health; Hydrogels; Recommendations; Robotics; Self healing materials; self-healing; self-recovery; Three dimensional printing; tough
• ISSN: 0935-9648; 1521-4095
• DOI: 10.1002/adma.201601613

Over the past few years, there has been a great deal of interest in the development of hydrogel materials with tunable structural, mechanical, and rheological properties, which exhibit rapid and autonomous self‐healing and self‐recovery for utilization in a broad range of applications, from soft robotics to tissue engineering. However, self‐healing hydrogels generally either possess mechanically robust or rapid self‐healing properties but not both. Hence, the development of a mechanically robust hydrogel material with autonomous self‐healing on the time scale of seconds is yet to be fully realized. Here, the current advances in the development of autonomous self‐healing hydrogels are reviewed. Specifically, methods to test self‐healing efficiencies and recoveries, mechanisms of autonomous self‐healing, and mechanically robust hydrogels are presented. The trends indicate that hydrogels that self‐heal better also achieve self‐healing faster, as compared to gels that only partially self‐heal. Recommendations to guide future development of self‐healing hydrogels are offered and the potential relevance of self‐healing hydrogels to the exciting research areas of 3D/4D printing, soft robotics, and assisted health technologies is highlighted. Autonomous self‐healing hydrogels are reviewed for the first time. Complete autonomous self‐healing can prolong the lifetime of hydrogel materials, prevent catastrophic failure, and is an emerging area of research. The field is likely to be opened up to many new applications by the combination of self‐healing with tough mechanical properties. 3D/4D‐printing, soft robotic actuators, and assisted health technologies are recognized as possible future applications for self‐healing hydrogels.