Morning Glory-Inspired Dual-Function Microcapsules for the Self-Reporting and Self-Healing of Electrothermal-Induced Damage of Electrical Devices.

The long-term operation of power equipment and power electronics can cause local overheating and discharges in the insulation material, resulting in irreversible insulation damage. Further development of such damage can eventually lead to equipment failure, but this problem is very difficult to solve. In this paper, inspired by how the petals of morning glory change color with the environment due to the presence of pigmented globules, a dual-function heat alert in the form of a self-healing (HASH) microcapsule with a nested structure is prepared by using microfluidic technology. By combination of the microcapsule with the insulation material, the local overheating in equipment can be detected promptly under live operating conditions without manual external intervention, and the defects that occur can be repaired autonomously. These HASH microcapsules can be pre-embedded in places at which the material is prone to overheating using artificial magnetic targeting. The doping of the matrix material with microcapsules does not cause any deterioration in its electrical or mechanical properties. This technology is expected to be applied to electrical equipment and electronic devices to allow for the early detection of local overheating and the autonomous repair of defects, thereby ensuring the safety of the equipment and improving its service life.

Magnetically Targeted, Water-Triggered, Self-Healing Microcapsules Based on Microfluidic Techniques Enabling Targeted Healing of Water Tree Damage in Epoxy Resins.

Repairing the micro-scale damage of insulating materials under a strong electric field has long been a highly desired but challenging task. Among all kinds of damage, water tree damage in the insulating materials of electrical equipment and electronic devices working in humid environments has long been considered irreparable. The main challenge is that residual water prevents the healing agent from filling the water tree branch channel. To solve this problem, this work reports a magnetically targeted, water-triggered, self-healing microcapsule (MTWTSH-MC) that makes a breakthrough against water tree damage based on microfluidic techniques. Targeted microcapsules driven by a directional magnetic field are concentrated to the vulnerable area of the insulating materials, exerting very limited effects on the dielectric. When damage breaks the microcapsules, the healing agent releases and quickly fills the damage channel and then reacts with water in the air or in the branch channel of the water tree, achieving solidification of the healing agent and self-healing of the damage channels. In this way, we can realize self-perception, self-triggering, and self-healing for both mechanical damage and water tree damage in insulation materials without any external stimulation.