Alshehhi Fatima, Waheed Waqas, Al-Ali Abdulla, Abu-Nada Eiyad, Alazzam Anas
Mechanical Engineering Department, Khalifa University, Abu Dhabi P.O. Box 127788, United Arab Emirates.
System on Chip Lab, Khalifa University, Abu Dhabi P.O. Box 127788, United Arab Emirates.
Micromachines (Basel). 2023 Jan 31;14(2):366. doi: 10.3390/mi14020366.
In this work, we employed the Immersed Boundary-Lattice Boltzmann Method (IB-LBM) to simulate the motion of a microparticle in a microchannel under the influence of a standing surface acoustic wave (SSAW). To capture the response of the target microparticle in a straight channel under the effect of the SSAW, in-house code was built in C language. The SSAW creates pressure nodes and anti-nodes inside the microchannel. Here, the target particle was forced to traverse toward the pressure node. A mapping mechanism was developed to accurately apply the physical acoustic force field in the numerical simulation. First, benchmarking studies were conducted to compare the numerical results in the IB-LBM with the available analytical, numerical, and experimental results. Next, several parametric studies were carried out in which the particle types, sizes, compressibility coefficients, and densities were varied. When the SSAW is applied, the microparticles (with a positive acoustic contrast factor) move toward the pressure node locations during their motion in the microchannel. Hence, their steady-state locations are controlled by adjusting the pressure nodes to the desired locations, such as the centerline or near the microchannel sidewalls. Moreover, the geometric parameters, such as radius, density, and compressibility of the particles affect their transient response, and the particles ultimately settle at the pressure nodes. To validate the numerical work, a microfluidic device was fabricated in-house in the cleanroom using lithographic techniques. Experiments were performed, and the target particle was moved either to the centerline or sidewalls of the channel, depending on the location of the pressure node. The steady-state placements obtained in the computational model and experiments exhibit excellent agreement and are reported.
在这项工作中，我们采用沉浸边界-格子玻尔兹曼方法（IB-LBM）来模拟微通道中微粒在驻表面声波（SSAW）影响下的运动。为了捕捉目标微粒在直通道中受SSAW作用时的响应，我们用C语言编写了内部代码。SSAW在微通道内产生压力节点和反节点。在此，目标粒子被迫朝着压力节点移动。我们开发了一种映射机制，以便在数值模拟中准确应用物理声学力场。首先，进行了基准研究，将IB-LBM中的数值结果与现有的解析、数值和实验结果进行比较。接下来，进行了几项参数研究，其中改变了粒子类型、尺寸、压缩系数和密度。当施加SSAW时，微粒子（具有正声对比度因子）在微通道中运动时朝着压力节点位置移动。因此，通过将压力节点调整到所需位置，如中心线或微通道侧壁附近，可以控制它们的稳态位置。此外，粒子的几何参数，如半径、密度和压缩性，会影响它们的瞬态响应，并且粒子最终会在压力节点处沉降。为了验证数值工作，我们在洁净室中使用光刻技术自行制造了一个微流体装置。进行了实验，目标粒子根据压力节点的位置移动到通道的中心线或侧壁。计算模型和实验中获得并报告的稳态位置表现出极好的一致性。
