Why self-healing materials could revolutionize modern engineering

The article discusses the emerging field of self-healing materials, which have the ability to autonomously repair damage such as cracks, scratches, or fractures without human intervention. Inspired by natural biological systems—like how human skin heals or how certain animals regenerate limbs—these materials mimic self-repair mechanisms to restore structural integrity. The concept is not entirely new; for example, ancient Roman concrete contained lime clasts that reacted with water to seal cracks, demonstrating an early form of self-healing. Self-healing materials come in various forms including polymers, metals, ceramics, and cement-based composites, and are generally classified into two main categories based on their repair mechanisms: extrinsic and intrinsic systems. Extrinsic materials contain embedded microcapsules or vascular networks filled with healing agents that are released upon damage to seal cracks, similar to blood clotting in animals. Intrinsic materials, on the other hand, rely on reversible chemical bonds within their structure that can break and reform, allowing repeated healing without external agents. Practical