Effective Properties of Thermo-Electro-Mechanically Coupled Smart Piezoelectric Nanocomposites

我们的研究项目致力于对含有由氧化锌和氮化镓制成的活性压电纳米线(NWS)的智能压电纳米复合材料(SPNC)的热电-机械行为进行精确的建模和实验表征。SPNC将为下一代轻质纳米结构复合材料奠定基础，这些复合材料将被用作传感器、执行器和能量收集器，用于需要多功能、自主性和适应性的应用。我们目前研究的一个重要方面是评估温度对NWS和SPNC的压电系数的影响，以促进对控制其机电行为的主要参数的基本了解。到目前为止，文献只包含了几个特殊病例的室温测量。这部分是由于原子测量的复杂性，部分是由于缺乏适当的设施。在这项RTI中，我们正在寻求支持，以获得配备有温度模块的压电力显微镜(PFM)，以便于进行这些必要的测量。PFM能够在高达±220V的尖端偏置下工作，对包括铁电和多铁在内的压电体进行非常高的灵敏度和无串扰测量。迫切需要这种PFM来研究热效应对NWS和SPNC的机电性能的影响，并验证我们的多尺度模型。我校现有的原子力显微镜无法测量SPNC和NWS的压电系数，要么是因为信噪比较大，要么是因为缺乏精确的温度控制能力。该设施将显著提高我们的测量能力和研究结果的质量。使用PFM进行的研究将导致：开发和创新具有成本效益的智能压电纳米复合材料，量化我们研究中控制SPNC耦合机电响应的主要成分，关于温度对这些耦合系数的影响的新知识，极大地提高对SPNC在不同温度下的行为的了解，并提供66 HQP的有效培训。

Our research program is concerned with the accurate modelling and experimental characterisation of the thermo-electro-mechanical behaviour of smart piezoelectric nanocomposites (SPNCs) containing active piezoelectric nanowires (NWs) made from Zinc Oxide and Gallium Nitride. SPNCs will form the foundation for next generation lightweight nanostructured composites to be used as sensors, actuators and energy harvesters for applications requiring multifunctionality, autonomy and adaptability. An essential aspect of our current research is the evaluation of the influence of temperature on the piezoelectric coefficients of NWs and SPNCs to facilitate fundamental understanding of the main parameters that govern their electromechanical behaviour. As of now, the literature only contains room temperature measurements of a few specialised cases. This is partially due to the complexity of the atomistic measurement and partially due to the lack of appropriate facilities. In this RTI, we are seeking support to acquire piezoresponse force microscope (PFM) equipped with a temperature module to facilitate these essential measurements. The PFM enables operation at high tip biases up to ±220V for very high sensitivity and crosstalk-free measurements on piezoelectrics, including ferroelectrics and multiferroics. This PFM is urgently needed to allow for the investigation of the thermal effects upon the electromechanical properties of NWs and SPNCs and to validate our multiscale models. The existing AFM in our university are incapable of measuring the piezoelectric coefficients of SPNCs and the NWs either because of the large signal-to-noise ratio or the lack of precise temperature control capabilities. The facility, which will significantly enhance our measuring capability and the quality of the outcomes of our research. Research carried out using PFM will lead to: development and innovative cost effective smart piezoelectric nanocomposites, quantification of a major component in our research that governs the coupled electromechanical response of SPNCs, new knowledge concerning the effect of temperature on these coupling coefficients, greatly improved understanding of the behaviour of SPNCs at varied temperature and provide effective training of 66 HQP.