Accelerated self-healing via ternary interpenetrating microvascular networks

Self-healing materials with dual interpenetrating microvascular networks enable two-part healing chemistries and repeated healing of damage in a localized region.1 However, due to slow healing kinetics, multiple days are required between damage events to recover mechanical performance under ambient conditions. By directly writing a third interdigitated microvascular network within these epoxy coating/substrate architectures to enable in situ thermal regulation, the characteristic healing time is reduced by an order of magnitude. Specifically, this third network provides a conduit for circulating a temperature-controlled fluid that rapidly heats the locally damaged region leading to a sharp reduction in the time required for mechanical property restoration. Self-healing materials with embedded ternary interpenetrating microvascular networks for thermally accelerated self-healing are fabricated by direct-write assembly (scale bar = 2 mm). Characterization of a bulk epoxy healing system demonstrates rapid healing at elevated temperatures. Circulation of a thermal fluid via an embedded microvascular network locally heats damaged regions, reducing healing times by over an order of magnitude.