Multidimensional particle fractioning using surface acoustic waves

对于许多工业应用，在过程工程和食品化学以及制药生产中，颗粒系统是至关重要的。在微流体中，由于平方立方定律，作用在粒子上的力的尺度不同。这里可以采用被动法和主动法进行分馏。被动方法，如惯性流动或流动聚焦，其优点是非常稳健，不需要外部能量。然而，应用外部场（如磁场、电场和声场）的主动方法以牺牲更复杂的系统为代价提供了更大的灵活性。两种类型的组合打开了建立一个灵活可控系统的可能性，该系统可以适应不同颗粒悬浮液的不同参数。因此，这些系统非常适合根据不同的性质分馏颗粒悬浮液。该研究项目的目的是建立一个系统，利用表面声波根据颗粒的大小、形状和声学对比度（密度和压缩性）来操纵和分类颗粒。为了能够表征这样的系统，需要应用深度神经网络来学习基于像散形变的粒子图像的粒子位置。此外，可以对网络进行训练，将该测量技术的适用性扩展到多分散的颗粒，并检测相应的颗粒大小和形状。最后，微流体分馏系统将在伊尔梅诺工业大学的技术中心（微纳米技术中心）生产，并进行详细的表征，以得出相关技术系统的设计结论，用于定制极细颗粒（< 500 nm）悬浮液的分馏。

For many industrial applications, in process engineering and food chemistry as well as pharmaceutical production, particulate systems are of vital importance. In microfluidics, forces acting on particles scale differently due to the square cube law. Here passive and active methods can be applied for fractionation. Passive methods such as inertial flow or flow focusing have the benefit to be very robust and do not require external energy. However, active methods applying external fields (such as magnetic, electric, and acoustic fields) offer a greater flexibility at the expense of more complex systems. A combination of both types opens the possibility to build a flexible and controllable system that can be adapted to the different parameters of varying particle suspensions. Therefore, these systems are well suited to fractionate particle suspensions by different properties. The aim of the research project is to setup a system using surface acoustic waves to manipulate and sort particles due to their size, shape and acoustic contrast (density and compressibility). In order to be able to characterize such systems, a deep neural network should be applied to learn the particle position based on astigmatically deformed particle images. In addition, the network can be trained to extend the applicability of this measurement technique to multi dispersed particles and to detect the corresponding size and shape of the particles. Finally, microfluidics fractionation systems shall be produced at the technology center (Center of Micro- and Nanotechnologies) at TU Ilmenau and characterized in detail, to draw conclusions on the design of technical relevant systems for the customizable fractioning of suspensions of very fine particles (< 500 nm).