Stimuli-triggered self-healing functionality in advanced fibre-reinforced composites

Abstract

Inspired by the sensory and autonomous healing processes of living organisms, whether from the Animalia or Plantae biological kingdoms, a microvascular network that undertakes a dual role of sensing structural damage before initiating a triggered healing response has been developed and embedded within an advanced fibre-reinforced composite [−45/90/45/0]2S laminate. In this study, a single vascule is used as a sensing pathway, which detects the introduction of ply delamination and matrix microcracking following a 10-J low-velocity impact event. Once damage connectivity between the sensing vascule and those open to the ambient environment is established, the delivery of a healing agent to the damage zone is triggered. An investigation into a commercially available epoxy healing agent (RT151) and an in-house healing resin formation (diglycidyl ether of bisphenol-A/diethylenetriamine) epoxy system has been evaluated. The pressure-assisted delivery of the liquid epoxy healing agent to the damage zone was observed to occur within 49 s across all specimens. The recovery of compression strength post impact was 91% and 94% for the RT151 and diglycidyl ether of bisphenol-A healing agents, respectively. This study provides further confirmation on how a bio-inspired vascular healing network could substantially enhance the reliability and robustness of advanced composite materials.

Self-healing composites: A review

“…Some of these sensing systems have been adopted for detection of cracks in self-healing materials Kirkby, de Oliveira, Michaud, & Månson, 2011;Trask, Norris, & Bond, 2014). For example, Hong and Su (2012) designed a multifunctional healing and monitoring system based on the vascular model by introducing conductive carbon powders and metallic micro-wires inside micro-tubes.…”

Optimal design of microvascular networks based on non-dominated sorting genetic algorithm II and fluid simulation

“…Intrinsic systems can repeatedly heal damage, but have strict request for the molecular structure of substrate material and it is difficult to demonstrate product. 6 As for the extrinsic systems, microcapsule [7][8][9][10] and hollow fiber 11,12 self-healing systems have been proven to be of high healing efficiency, but for the same crack, can only achieve a single repair. The microvascular network systems, [13][14][15][16][17][18][19][20] also belong to the extrinsic systems, are capable of multiple healing cycles and can be applied to a variety of substrate material.…”

Using feedback control to actively regulate the healing rate of a self-healing process subjected to low cycle dynamic stress

“…This means that there is no measure of capturing the incipient cause of damage, no guarantee of matching the healing rate to the damage rate and healing is passively initiated only after damage occurs. Nonetheless, a few works have reported integration of sensing into self-healing processes with the aim of improving the reliability of local detection, diagnosis and efficiency of healing (see table 1 for a summary) [7,[31][32][33][34][35][36]. A damage detection system consisting of a pressure sensor located in a pressurised vascular network and whose output was monitored through a microprocessor was used to trigger the delivery of healing resin from an external reservoir when a crack occurs [7].…”

“…Nonetheless, a few works have reported integration of sensing into self-healing processes with the aim of improving the reliability of local detection, diagnosis and efficiency of healing (see table 1 for a summary) [7,[31][32][33][34][35][36]. A damage detection system consisting of a pressure sensor located in a pressurised vascular network and whose output was monitored through a microprocessor was used to trigger the delivery of healing resin from an external reservoir when a crack occurs [7]. Distributed fibre sensors mounted on a composite plate to detect the pressure drop and initiate the supply of healing agent from an external source has also been reported [31].…”