声表面波微驱动技术在生物医学和化学分析等领域具有广阔的应用前景，近年来引起了学界极大的关注。能够原位实时地检测声表面波的传播特性对于声表面波在微驱动领域的应用具有重要意义。当前的检测方法面临仪器精密昂贵，运行费用高，对环境振动敏感，检测费时费力，不能实现原位实时快速检测等诸多问题。压电光子学效应能够实现机械应力到发光的转换。申请人研究组在国际上较早开展压电光子学效应研究。本项目拟在前期工作基础上，将应力发光薄膜与声表面波器件集成，基于压电光子学效应实现声表面波的可视化。研究工作预期将掌握应力发光薄膜特性以及声表面波参数对声波驱动应力发光性能的影响规律，理解声表面波耦合动态调制应力发光的物理机制，建立相应的物理模型。拟研发的新型可视化声表面波微驱动原型器件将验证新引入的发光功能不仅满足声表面波的现场快速可视化检测，而且有助于提高声表面波技术在微驱动和微操控领域的性能。

Surface acoustic wave (SAW) technologies have been extensively used as micro actuators for pumping or mixing of fluids and manipulation of micrometer sized objects, such as microparticles, droplets, and biological cells, which is highly desirable for many applications in biology, chemistry and engineering. The visualization of SAW is essential for characterizing the acoustic field in these operations, as well as for designing and testing interdigital transducers (IDTs). However, probing the acoustic propagation in these applications remains expensive, time-consuming, and often difficult to perform in situ. Technologies such as laser vibrometry, laser heterodyne interferometry, scanning acoustic force microscopy, and stroboscopic topography, do not allow direct access to close systems, as would be the case inside a channel, and are impractical for an in situ and rapid analysis. In this proposal, we demonstrate that the propagation path of SAWs excited with IDTs can be visualized by coupling acoustic field to piezophotonic effect. Piezophotonic effect, known as a two-way coupling effect between piezoelectricity and photoexcitation properties, is proposed to initiate the mechanoluminescence (ML) during the conversion process between mechanical strain and light emission. According to the piezophotonic effect, the interaction of the acoustic wave with the ML film gives rise to ML film deformations and results in light emission. We will study the influences of the characterizations of ML films and SAWs on the piezophotonic luminescence. The physical mechanism of the acoustic field induced ML and the theoretical model to describe the light emission induced by coupling acoustic field to piezophotonic effect will be proposed. Moreover, the method not only enables the visualization of the SAW path itself, but it also provides the information of the acoustic radiation pressure, which could improve the performance of visualized SAW-based actuator prototypes.