Nondestructive 3D Imaging of Microscale Damage inside Polymers—Based on the Discovery of Self‐Excited Fluorescence Effect Induced by Electrical Field

Abstract

The development of high‐precision, non‐destructive, and three‐dimensional (3D) in situ imaging of micro‐scale damage inside polymers is extremely challenging. Recent reports suggest that 3D imaging technology based on micro‐CT technology causes irreversible damage to materials and is ineffective for many elastomeric materials. In this study, it is discovered that electrical trees inside silicone gel induced by an applied electric field can induce a self‐excited fluorescence effect. Based on this, high‐precision, non‐destructive, and 3D in situ fluorescence imaging of polymer damages is successfully achieved. Compared with the current methods, the fluorescence microscopic imaging method enables slicing of the sample in vivo with high‐precision operation, realizing the precise positioning of the damaged area. This pioneering discovery paves the way for high‐precision, non‐destructive, and 3D in situ imaging of polymer internal damage, which can solve the problem of internal damage imaging in insulating materials and precision instruments.

In Situ Self-Fluorescence 3D Imaging of Micro/Nano Damage in Silicone Gel for Understanding Insulation Failure under High-Frequency Electric Fields

“…However, detailed investigations of the morphology of internal electrical damage to polymers have long posed a challenge, especially given the limitations of existing 3D studies of damage morphology. In previous experiments, , we found that when an electrical tree was induced in silicone gel under the action of a strong electric field, the channel of the tree exhibited a fluorescence response to a laser at a specific wavelength (488 or 596 nm). This is an interesting discovery that provides a new way of thinking for internal damage detection of insulating materials.…”

“…These problems have hindered research on 3D micromorphology and the growth mechanism of electrical trees in silicone gel. We have found that when a strong electric field is applied to silicone gel, 37,38 the internal damage channel will exhibit a self-excited fluorescence phenomenon, with the fluorescence intensity being positively correlated with the external electric field and the severity of the damage. This interesting discovery opens the way to 3D nondestructive in situ imaging of the internal structure of packaging materials such as silicone gels for precision devices.…”

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

“…There have been many studies on the growth processes and damage mechanisms of electrical trees. Considering three-dimensional (3D) morphology, − this paper explores the electrical damage volume under the action of different voltage sources using a laser scanning confocal microscope . In this study, an electrical tree growth test platform was built to observe the growth and repair of electrical trees under a power frequency voltage.…”