CNT微结构骨架/PVDF膜双模夹层式柔性传感器及其静动态应变传感性能

Fabrication and static/dynamic strain sensing performances of CNT microstructure skeleton/PVDF membrane dual mode sandwich flexible sensor

  • 摘要: 工程结构构造、应变信号复杂性使当前结构健康监测(SHM)用传感器面临刚度偏大、传感性能不佳、鲁棒性不足等挑战。具备同步感知静/动态复杂应变信号的双模式传感器开发是解决复杂应变信号感知与结构监测的有效策略。本文用微波烧蚀法制备碳纳米管(CNT)多孔烧蚀骨架充当压阻层,用流延法制备聚偏氟乙烯(PVDF)薄膜,经极化转变后充当压电层,然后引入聚二甲基硅氧烷(PDMS)弹性体封装成压阻/压电双模夹层式柔性传感器(PREFS),分别测试PREFS在静/动态荷载作用下应变灵敏度、线性度、稳定度等传感器性能。结果发现:PREFS组装厚度仅2.2 mm,柔韧性好(弯曲角可达180°),PREFS压阻层具有高灵敏度(GF=259.69%/mV)、高线性度(R2=0.997)及低迟滞性(γR=6.67%);相应其压电层的灵敏度GF=0.038 mV/N、线性度R2=0.953,频率响应仅9.4 ms。同时,PREFS能灵敏地感知手指0-90°弯曲和静/动态应变幅值0-1720 με加卸载情况。

     

    Abstract: The complexity of engineering structure and strain signal makes the current sensors for structural health monitoring (SHM) face challenges such as high stiffness, poor sensing performance, and insufficient robustness. The development of dual-mode sensor with synchronous sensing of static and dynamic complex strain signals is an effective strategy to solve the problem of complex strain signal sensing and structural monitoring. In this paper, the carbon nanotubes (CNTs) porous ablation skeleton was prepared by microwave ablation method as the piezoresistive layer, and the polyvinylidene fluoride (PVDF) film was prepared by tape casting method. After polarization transformation, it served as the piezoelectric layer. Then polydimethylsiloxane (PDMS) elastomer was introduced to package the piezoresistive/piezoelectric dual-mode sandwich flexible sensor (PREFS). The strain sensitivity, linearity, stability and other sensor performance of PREFS under static/dynamic load were tested respectively. The results show that the assembly thickness of PREFS is only 2.2 mm and the flexibility is good (the bending angle can reach 180°). The piezoresistive layer of PREFS has high sensitivity (GF=259.69%/mV), high linearity (R2=0.997) and low hysteresis (γR=6.67%); The sensitivity of the piezoelectric layer is GF=0.038 mV/N, the linearity R2=0.953, and the frequency response is only 9.4 ms. At the same time, PREFS can sensitively sense the finger 0-90° bending and static/dynamic strain amplitude 0-1720 με loading and unloading.

     

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