Due to the good reliability and long-term stability,
self-healing
hydrogels have emerged as promising soft materials for tissue engineering,
smart wearable sensors, bioelectronics, and energy storage devices.
The self-healing mechanism depends on reversible chemical or physical
cross-linking interactions. Self-healing hydrogels with fascinating
features (including mechanical performances, biocompatibility, conductivity,
antibacterial ability, responsiveness, etc.) are being designed and
developed according to the practical application requirements. In
this review, the recent progress on self-healing hydrogels in their
synthesis strategies and multiple applications is summarized. Their
synthesis strategies involve reversible chemical or physical cross-linking
processes or a combination of the two. Their recent applications include
flexible strain sensors, supercapacitors, actuators, adhesives, wound
healing, drug delivery, tumor treatment, 3D printing, etc. Finally,
the current challenges, future development, and opportunities for
self-healing hydrogels are discussed.