3D Phononic-Fluidic Systems for Liquid Mixture Analysis and Control

该项目旨在通过将具有重要声学意义的微结构与含有可交换分析物的微流控元素相结合，来研究一类全新的微系统，即声子-流体系统。这种结合将为一类新的设备铺平道路，用于各种流体的声学分析和控制，从水和酒精等简单液体、清洁混合物和溶液，到细胞培养或血液等复杂液体。了解弹性波和声波在这种微结构材料中的传播和共振现象是这些器件的理论基础。快速发展的添加剂制造的可能性为在单个部件中实现复杂的3D几何形状和多种功能的集成奠定了技术基础。声子晶体是光学上的光子晶体的声学等价物，它提供了独特的能带结构来操纵声波的传播。加法制造将被用来实现具有超出相应2D设计能力的带隙特性的3D声子晶体。同样，将流体特征作为缺陷添加到声子晶格中将是本工作探索的第一个器件概念。声子-流体腔缺陷充当声谐振器，它结合了谐振式传感器的高灵敏度和超声波传感器探测流体体积属性的能力。空腔缺陷共振将被设计成落入声子带隙，并根据液体分析物的物理性质，如声速、密度、粘度和浓度，产生高度敏感和无扰的共振峰。进一步的研究将包括一种全三维方法来安排流体元素周围和内部的声子结构。这将从根本上实现新的设备，最终将不同的物理功能组合在单个结构元素中。波导结构将被引入微通道周围的声子晶格中，以将声能精确地聚焦到任意位置，从而产生独特的流体流动的空间分辨率。最后，集成在微通道中的周期性微结构将首次同时用作流体滤光器和声粒子探测器。综上所述，该项目的重要目标包括：1.优化能带结构的三维声子晶体的设计、实现和表征的理论和技术基础。3D声子-流体腔传感器作为高灵敏度的方法，用于液体和混合物的体积特性的局部测量。通过集成(亚)微米声子-流体元件用于粒子检测和操纵，在单个结构元件中突破性地融合了多种物理功能。

This project aims at a fundamentally new class of microsystems, namely phononic-fluidic systems, by combining acoustically significant microstructures with microfluidic elements containing exchangeable analytes. This combination will pave the way for a new class of devices for the acoustic analysis and control of a variety of fluids, from simple liquids like water and alcohols, clean mixtures and solutions to complex liquids like cell cultures or blood. Understanding elastic and acoustic wave propagation and resonance phenomena in such microstructured materials is the theoretical foundation of these devices. The rapidly growing possibilities of additive manufacturing form the enabling technological basis to realize complex 3D geometries and integration of multiple functionalities in single parts.Phononic crystals, acoustic equivalent of photonic crystals from optics, offer unique band structures to manipulate acoustic wave propagation. Additive fabrication will be used to realize 3D phononic crystals with band gap characteristics beyond the capabilities of corresponding 2D designs. Likewise, adding fluidic features into a phononic lattice as defects will be the first device concept explored in this work. A phononic-fluidic cavity defect acts as an acoustic resonator that combines the high sensitivity of resonant sensors with the ability of ultrasonic sensors to probe volumetric properties of fluids. The cavity defect resonance will be designed to fall into a phononic band gap and yield a highly sensitive and unperturbed resonance peak dependent on the physical properties of the liquid analyte, such as speed of sound, density, viscosity, and concentration.Further research will include a fully three-dimensional approach to arrange phononic structures around and inside fluidic elements. This will enable fundamentally new devices ultimately combining different physical functionalities within a single structural element. Waveguide structures will be introduced into a phononic lattice around a microchannel to precisely focus acoustic energy into arbitrary locations, resulting in a unique spatial resolution of the fluid flow. Finally, periodic microstructures integrated inside a microchannel will for the first time simultaneously act as fluidic filter and acoustic particle detector.In summary, significant objectives of the project include:1. Theoretical and technological foundation for design, realization and characterization of 3D phononic crystals with optimized band structures.2. 3D phononic-fluidic cavity sensors as highly sensitive methodology for localized measurement of volumetric properties of liquids and mixtures.3. Groundbreaking fusion of multiple physical functionalities in single structural elements by integrating (sub-)micron phononic-fluidic elements for particle detection and manipulation.