Advanced microbridge structure for reduced thermal conductivity in uncooled infrared microbolometers

IF 4.9 3区工程技术 Q2 ENGINEERING, ELECTRICAL & ELECTRONIC

Sensors and Actuators A-physical Pub Date : 2025-09-30 DOI:10.1016/j.sna.2025.117102

Yan Zhao , Zirui Yang , Chengchen Gao , Zhenchuan Yang

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Abstract

The recent advancement of microbolometers, as a representative uncooled thermal sensing technology, has significantly promoted the development of low cost infrared imaging systems for both military and commercial applications. In this work, we experimentally demonstrated an uncooled infrared bridge microbolometer using beams with constant strength (BCS) design that simultaneously achieves low thermal conductivity and high mechanical integrity. A comprehensive analytical model is established to optimize the stress distribution along the supporting beams, yielding a reduced standard deviation of maximum first principal stress to 5.5 MPa and 13.7 MPa for single-layer and multi-layer configurations, respectively. Numerical simulations further address the analytical approximations and refine these results, lowering the stress variation to 4.997 MPa in the multi-layer beams. Experimental validation of the BCS design demonstrated a 3.53-fold improvement in readout voltage under vacuum compared to conventional constant-width beams, achieving a responsivity of 1.4 × 10⁵ V/W. This work demonstrates enhanced responsivity of BCS geometry in microbolometer design, offering a promising route for thermal conductivity management and structural optimization methodologies in next-generation complex infrared sensing systems.

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用于降低非冷却红外微辐射热计导热系数的先进微桥结构

微辐射热计作为非制冷热传感技术的代表，近年来的进步极大地促进了军用和商用低成本红外成像系统的发展。在这项工作中，我们通过实验展示了一种采用恒强度（BCS）设计的光束的非冷却红外桥式微辐射热计，同时实现了低导热性和高机械完整性。建立了沿支承梁应力分布的综合分析模型，得到单层和多层结构下最大第一主应力标准差分别为5.5 MPa和13.7 MPa。数值模拟进一步解决了解析近似，并对这些结果进行了改进，将多层梁的应力变化降至4.997 MPa。实验验证表明，与传统的等宽光束相比，BCS设计在真空下的读出电压提高了3.53倍，响应率达到1.4 × 105 V/W。这项工作证明了BCS几何结构在微测热计设计中的响应性增强，为下一代复杂红外传感系统的热导率管理和结构优化方法提供了一条有前途的途径。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Sensors and Actuators A-physical 工程技术-工程：电子与电气

CiteScore

8.10

自引率

6.50%

发文量

630

审稿时长

49 days

期刊介绍： Sensors and Actuators A: Physical brings together multidisciplinary interests in one journal entirely devoted to disseminating information on all aspects of research and development of solid-state devices for transducing physical signals. Sensors and Actuators A: Physical regularly publishes original papers, letters to the Editors and from time to time invited review articles within the following device areas: • Fundamentals and Physics, such as: classification of effects, physical effects, measurement theory, modelling of sensors, measurement standards, measurement errors, units and constants, time and frequency measurement. Modeling papers should bring new modeling techniques to the field and be supported by experimental results. • Materials and their Processing, such as: piezoelectric materials, polymers, metal oxides, III-V and II-VI semiconductors, thick and thin films, optical glass fibres, amorphous, polycrystalline and monocrystalline silicon. • Optoelectronic sensors, such as: photovoltaic diodes, photoconductors, photodiodes, phototransistors, positron-sensitive photodetectors, optoisolators, photodiode arrays, charge-coupled devices, light-emitting diodes, injection lasers and liquid-crystal displays. • Mechanical sensors, such as: metallic, thin-film and semiconductor strain gauges, diffused silicon pressure sensors, silicon accelerometers, solid-state displacement transducers, piezo junction devices, piezoelectric field-effect transducers (PiFETs), tunnel-diode strain sensors, surface acoustic wave devices, silicon micromechanical switches, solid-state flow meters and electronic flow controllers. Etc...