Acoustic tweezers - 논문 읽고 리뷰하자

Acoustic tweezers are a powerful, versatile set of tools that use sound waves to manipulate bioparticles ranging from nanometer-sized extracellular vesicles to millimeter-sized multicellular organisms. Over the past several decades, the capabilities of acoustic tweezers have expanded from simplistic particle trapping to the precise rotation and translation of cells and organisms in three dimensions.

"However, at the end of the day, the success of this field depends on whether end users such as biologists, chemists or clinicians are willing to adopt this technology or not. This paper demonstrates a step toward a much friendlier workflow to make it easier for end users to adopt this technology."

In their first application, acoustic tweezers used sound waves generated from opposite sides of a microfluidic chip or chamber to create nodes where cells or microparticles are trapped. Moving the wavefronts of the sound waves across the opposing surfaces of the chamber controlled a particle's position in two dimensions, while adjusting the sound waves' amplitudes could push or pull them in the third.

More advanced setups have since been demonstrated, where sound waves reverberate throughout a fluidic chamber. For example, depending on the application, patterns can be created and changed to separate and manipulate multiple particles at once, or whirlpools can be formed to concentrate a group of particles.

In the first design, a set of four transducers, one on each side of the Petri dish, create sound waves that interact with one another to create a standing pattern within the dish's liquid sample. The setup could be used for multi-configuration cell patterning, cell-cell interaction studies and the construction of 3-D tissues.

The second design uses a tilted transducer sending an angled sound wave from beneath the Petri dish to create a whirlpool that concentrates the dish's contents in the center. This ability would allow researchers to concentrate bioparticles for signal enhancement and the construction of large cell spheroids.

In the final setup, holographic interdigital transducers—two transducers fitted together like a zipper—create high-frequency beam-like waves from below the Petri dish to control particles in specific locations. By switching between different designs, the setup can stimulate cells as well as concentrate and trap bioparticles.

Together, the setups demonstrate easy-to-use acoustic tweezers that can gently manipulate a wide variety of cells and particles without touching or labeling them. Potential applications include patterning and printing cells, separating and sorting cells, controlling cell-cell interactions, constructing tissues and rotating multicellular organisms.

 

reference

"Generating multifunctional acoustic tweezers in Petri dishes for contactless, precise manipulation of bioparticles" Science Advances (2020). DOI: 10.1126/sciadv.abb0494