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

该项目旨在通过将声学上重要的微结构与含有可交换分析物的微流控元件相结合，研究一种全新的微系统，即声子流体系统。这种组合将为一种新型设备铺平道路，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物或血液等复杂液体。了解这些微结构材料中的弹性和声波传播和共振现象是这些器件的理论基础。快速增长的增材制造的可能性形成了使能的技术基础，以实现复杂的3D几何形状和多个功能在单个零件的集成。声子晶体是光学中光子晶体的声学等效，它提供了独特的能带结构来控制声波的传播。增材制造将用于实现三维声子晶体，其带隙特性超出了相应的二维设计能力。同样，将流体特征添加到声子晶格中作为缺陷将是本工作中探索的第一个器件概念。声子-流体腔缺陷作为一种声学谐振器，结合了谐振传感器的高灵敏度和超声波传感器探测流体体积特性的能力。空腔缺陷共振将被设计成落在声子带隙中，并根据分析液的物理性质（如声速、密度、粘度和浓度）产生高度敏感和不受干扰的共振峰。进一步的研究将包括一种完全三维的方法来排列流体元件周围和内部的声子结构。这将使全新的设备最终在单一结构元素中结合不同的物理功能成为可能。波导结构将被引入到微通道周围的声子晶格中，以精确地将声能聚焦到任意位置，从而产生独特的流体流动空间分辨率。最后，集成在微通道内的周期性微结构将首次同时充当流体过滤器和声学粒子检测器。综上所述，本项目的主要目标包括：1。具有优化能带结构的三维声子晶体设计、实现和表征的理论和技术基础三维声子-流体腔传感器作为液体和混合物体积特性局部测量的高灵敏度方法。通过集成（亚）微米声子-流体元件进行粒子检测和操作，在单一结构元件中开创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.