Boudreaux Taylor, Freyhof Luke, Riehl Brandon D, Kim Eunju, Pedrigi Ryan M, Lim Jung Yul
Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA.
Department of Biological Systems Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588, USA.
Bioengineering (Basel). 2025 Apr 25;12(5):458. doi: 10.3390/bioengineering12050458.
The open and contactless environment of acoustic levitation provides a unique condition in experimenting with varying substances while levitated for observation and implementation with other devices, with recent improvements in cost and accessibility. We briefly decipher the theory behind acoustic levitation and describe currently available levitation platforms. Then, how these platforms have been employed in biological applications is reviewed. Intriguingly, recent researches indicated the viability of acoustic levitation to be utilized as a microgravity simulator. We introduce existing on-ground microgravity platforms, and discuss the potential of acoustic levitation in simulating microgravity. Acoustic levitation could be an alternative to microgravity platforms such as clinostats while allowing for novel microgravity research. On the other hand, the microgravity provided by acoustic levitation may be restricted due to potential limitations in the available levitation volume, relatively larger gravity compared to 10 g centrifugal acceleration from clinostats, and probable instability due to air perturbations and acoustic streaming. With more knowledge about in-droplet particle rotation and the regulatory factors during levitation, acoustic levitation may provide a new and advanced platform for microgravity simulation via taking advantage of its availability for real-time observation and manipulation of samples via added instrumentation while samples are levitated in a simulated microgravity condition.
声悬浮的开放和非接触环境为悬浮各种物质进行实验以进行观察以及与其他设备配合使用提供了独特条件，且在成本和可及性方面有了最新改进。我们简要解读声悬浮背后的理论，并描述当前可用的悬浮平台。然后，回顾这些平台在生物应用中的使用情况。有趣的是，最近的研究表明声悬浮可作为微重力模拟器使用。我们介绍现有的地面微重力平台，并讨论声悬浮在模拟微重力方面的潜力。声悬浮可以成为诸如回转器等微重力平台的替代方案，同时允许进行新颖的微重力研究。另一方面，声悬浮提供的微重力可能受到限制，原因在于可用悬浮体积的潜在限制、与回转器产生的10g离心加速度相比相对较大的重力，以及由于空气扰动和声流可能导致的不稳定性。随着对液滴内颗粒旋转以及悬浮过程中调节因素的更多了解，声悬浮可以通过利用其在样品悬浮于模拟微重力条件下时通过添加仪器对样品进行实时观察和操作的能力，为微重力模拟提供一个新的先进平台。
