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XJTU achieves breakthrough in micro-nano scale vacuum insulation and field emission theory

July 18, 2025
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The relationship between field emission characteristic parameters and R/d.

Field-induced electron emission serves as the primary initiating mechanism for vacuum breakdown and insulation failure, forming the theoretical foundation for vacuum insulation design and application in high-performance electrical equipment and micro-nano electronic devices.

However, when dielectric systems or electrodes operate at nanoscale dimensions, field emission behavior is not only governed by quantum tunneling effects but also significantly influenced by space charge quantum effects and electrode size effects.

This leads to deviations between classical theoretical predictions and experimental results, rendering traditional field emission equations inadequate for describing nanoscale emission phenomena. Establishing a universal theoretical framework for nanoscale field emission is therefore critical.

To address these challenges, Professor Meng Guodong's team from the School of Electrical Engineering and the State Key Laboratory of Electrical Insulation and Power Equipment at Xi'an Jiaotong University (XJTU) collaborated with Professor Lay Kee Ang's team at the Singapore University of Technology and Design.

Building on prior achievements (Physics of Plasmas 31 (4), 040502, 2024; Physical Review Letters 132 (17), 176201, 2024), they developed an in-situ breakdown and characterization technique using transmission electron microscopy. This approach systematically investigated the intrinsic field emission properties of nanoscale tungsten electrode structures (tip radius: 2–190 nm) in vacuum nanogaps (5–100 nm).

Their research combines in-situ experiments with theoretical analysis to reveal, for the first time, the geometric shape effects of field emission at the nanoscale. It bridges gaps in classical field emission theory within nanoscale domains and provides crucial theoretical support for optimizing insulation design in high-performance electrical equipment and micro-nano electronic devices.

These findings have been published in Nature Communications under the title Uncovering a widely applicable empirical formula for field emission characteristics of metallic nanotips in nanogaps.