Acoustic driven circulation around cylindrical obstructions in microchannels
Acoustic driven circulation around cylindrical obstructions in microchannels
复制标题
DOI：
10.1063/5.0172640
复制
发表时间：
2023-11
影响因子：
4.6
通讯作者：
Md. Abdul Karim Miah;Peter Zeller;Michael G. Olsen;Jaime J. Juárez
中科院分区：
文献类型：
--
作者：
Md. Abdul Karim Miah;Peter Zeller;Michael G. Olsen;Jaime J. Juárez
我们介绍了一种方法来产生方向控制循环周围的圆柱形障碍物的通道使用压电换能器嵌入多孔通道设备制造的光刻。为了将声信号传输到通道中，连接单个压电换能器，在5、10、15和20 V的电压水平下操作。采用显微粒子图像测速法来分析通道中的流型。分析表明，两个相反的流通趋势周围的支柱位于两个相对侧的通道在纵向方向。循环强度在通道中部最小，向通道两端逐渐增加。此外，我们观察到，循环强度是最大的轴向中心线附近和最小的边界处沿着的通道宽度。比较电压电平，在所有情况下，较高电压信号比较低电压信号产生更高的循环强度。此外，我们发现，流通的强度几乎线性增加，然后从柱的表面沿径向呈指数衰减。观察到的速度场周围的个别气缸匹配良好的Görtler涡模型。所报道的围绕柱的循环现象可以应用于生物化学系统和芯片实验室系统中的非接触式流体搅拌和混合，并且还可以在物体镊子、捕获和悬浮中提供额外的自由度。
We introduce an approach to generate direction-controlled circulation around cylindrical obstructions in channels using a piezoelectric transducer embedded porous-channel device fabricated by photolithography. To transmit acoustic signals into the channel, a single piezoelectric transducer was attached, operating at voltage levels of 5, 10, 15, and 20 V. Microscopic particle image velocimetry was employed to analyze the flow patterns in the channels. The analysis revealed two opposing circulation tendencies around the pillars located at two opposite sides of the channel in the longitudinal direction. The strength of circulation was found to be minimal in the middle of the channel and increased gradually toward the two ends of the channels. Furthermore, we observed that the circulation strength was maximum near the axial centerline and minimum at the boundaries along the width of the channels. Comparing the voltage levels, the higher voltage signals produced a higher strength of circulation than the lower voltage signals in all cases. Additionally, we found that the strength of circulation increased almost linearly and then decayed exponentially in the radial direction from the surfaces of the pillars. The observed velocity fields around individual cylinders matched well with the Görtler vortex model. The reported circulation phenomenon around pillars can be applied in non-contact fluid stirring and mixing in bio-chemical systems and lab-on-a-chip systems and may also provide additional degrees of freedom in object tweezing, trapping, and levitation.