论文标题
旅行超声波对锥形纳米和微粒的方向依赖性推进
Orientation-dependent propulsion of cone-shaped nano- and microparticles by a traveling ultrasound wave
论文作者
论文摘要
先前关于超声螺旋形纳米和微粒的研究仅考虑了粒子方向垂直于超声传播方向的系统。但是，在这些粒子的未来应用中，它们通常也能够达到其他方向。因此，使用直接的大声流体模拟，我们在这里研究了锥形纳米和微粒的推进，这些纳米和微粒如何具有特别有效的声学推进，因此是对未来应用的有希望的候选者，取决于它们相对于旅行超声波的繁殖方向相对于它们的方向。我们的结果表明，颗粒的推进在很大程度上取决于它们相对于波传播方向的方向，并且颗粒倾向于垂直于波动方向定向。我们还提出了粒子的方向平均翻译和角速度，这对应于颗粒对各向同性暴露于超声的有效推进。我们的结果允许评估自由超声螺旋体胶体颗粒如何在三个空间维度中移动，从而构成了实现此类颗粒未来应用的重要一步。
Previous studies on ultrasound-propelled nano- and microparticles have considered only systems where the particle orientation is perpendicular to the direction of propagation of the ultrasound. However, in future applications of these particles, they will typically be able to attain also other orientations. Therefore, using direct acoustofluidic simulations, we here study how the propulsion of cone-shaped nano- and microparticles, which are known to have a particularly efficient acoustic propulsion and are therefore promising candidates for future applications, depends on their orientation relative to the propagation direction of a traveling ultrasound wave. Our results reveal that the propulsion of the particles depends strongly on their orientation relative to the direction of wave propagation and that the particles tend to orient perpendicularly to the wave direction. We also present the orientation-averaged translational and angular velocities of the particles, which correspond to the particles' effective propulsion for an isotropic exposure to ultrasound. Our results allow assessing how free ultrasound-propelled colloidal particles move in three spatial dimensions and thus constitute an important step towards the realization of the envisaged future applications of such particles.
