Aerosol generation out of thin fluid films using surface acoustic waves

这一建议涉及到在与表面声波（SAW）相互作用过程中，由压电基板上的数字间换能器（IDT）激发的薄流体膜产生气溶胶的物理基础的持续研究。这一提议的主要重点是实验和理论研究声表面波与位于IDT孔径外的小体积流体的相互作用。这包括薄流体膜的产生，其在IDT孔径方向的横向过渡以及从薄流体膜中产生气溶胶液滴。因此，目标是确定流体膜和气溶胶的特性作为SAW的材料特性（如粘度）和实验边界条件（如声波场）的函数。为了一种新的、有前途的流体供应方法和驻波场的应用，应该对这些参数已经建立的模型进行评估和扩展。此外，对于流体薄膜平移和气溶胶产生的开始，以及雾化区域的温度，应该制定新的模型。利用位于IDT孔径外的玻璃毛细血管或微通道的连续流体供应，如提议者所评估的那样，因此可作为实验基础。通过在空间上分离流体供应区和雾化区，提高了过程控制和重现性，优化了液滴尺寸分布，简化了SAW与流体复杂的非线性相互作用的数学描述。此外，它使可靠的技术使用和未来集成在医药或生物技术的手持设备中。

This proposal concerns the continuative research for the physical fundamentals of the aerosol generation out of thin fluid films during their interaction with surface acoustic waves (SAW), which are excited via interdigital transducers (IDT) on piezoelectric substrates. The main focus of this proposal is the experimental and theoretical investigation of the interaction of SAW with a small fluid volume located outside of the IDT aperture. This comprises the generation of a thin fluid film, its lateral transition in the direction of the IDT aperture and the generation of aerosol droplets out of the thin fluid film. Thereby, the target is the determination of properties of the fluid film and the aerosol as functions of the material properties (e.g. viscosity) and the experimental boundary conditions (e.g. acoustic wavefield) of the SAW. Already established models for these parameters should be evaluated and extended for a new, promising fluid supply method and the application of standing wavefields. Additionally, new models should be formulated for the onset of fluid thin film translation and aerosol generation, as well as for the temperature in the atomization zone. The continuous fluid supply using glass capillaries or microchannels located outside of the IDT aperture, as evaluated by the proposer, thereby serves as experimental base. It improves process control and reproducibility, optimizes the droplet size distribution and simplifies the mathematical description of the complex, nonlinear interaction of SAW and fluid by spatially separating fluid supply and atomization zone. Furthermore, it enables a reliable technical use and the future integration in hand-held devices for medicine or biotechnology.