柔性压阻应变传感技术在结构健康监测领域的研究进展

Research progress of flexible piezoresistive strain sensing technology in structural health monitoring

柔性压阻应变传感器具备量程大、共形能力强、稳定性好等优势,为解决传统应变传感器量程小和灵敏度低等难题提供新途径,在土木工程领域结构健康监测中有很大的应用潜力。在介绍柔性压阻应变传感器常用的材料及其传感机理基础上,归纳并总结了3种典型压阻传感原理的传感机制、传感器结构设计和制备方法以及在结构健康监测中的应用等三方面的研究现状。通过探讨材料选择、导电网络优化设计对传感性能调控的影响,发现采用复合导电填料和微观结构设计能一定程度提高传感性能;现阶段制造高性能且适应工程环境的柔性压阻应变传感器面临长期使用过程的性能下降、工程环境下的稳定性、监测系统集成维护等挑战;对于柔性压阻传感器的选择策略,建议选择碳系导电材料,选择不同主导的导电效应来满足对不同应变监测的需求;同时,展望了柔性压阻应变传感器在建筑结构智慧运维中的发展趋势。

Flexible piezoresistive strain sensors have the advantages of large sensing range,excellent deformation adaptability,and good stability,which provide new approaches to solving the problems of the traditional strain sensors such as small range and low sensitivity,and show great application potential in the civil structural health monitoring(CSHM).In this paper,the common materials and basic sensing mechanisms of the flexible piezoresistive strain sensors were introduced.The state-of-art of three typical piezoresistive sensing principles was summarized in three aspects,including sensing mechanism,structural design and preparation method,and their applications in CSHM.The influences of material selection and conductive network optimization design on sensing performance control were analyzed.It is found that he use of composite conductive fillers and microstructure design can improve sensing performance.The development of high-performance and adaptable flexible piezoresistive strain sensors for engineering environments still faces problems such as material aging during long-term operation,unstable performance in engineering environments,and difficulty in system integration and maintenance.For the selection strategies of flexible piezoresistive sensors in CSHM,carbon-based conductive materials have better comprehensive performance,and flexible sensors with interface contact effect as the dominant mechanism are more suitable for strain monitoring needs of civil engineering structures.Finally,the prospect of the flexible piezoresistive sensors in intelligent operation and maintenance of civil engineering was presented.