Abstract

The ability to manipulate cells and other micro-particles in a completely biocompatible and dexterous manner is critical for numerous biological studies and applications such as cell-cell communication, biosensing, tissue engineering, and regenerative medicine. Here we present an “acoustic manipulators” technique that utilises acoustic standing waves to manipulate particles, cells, and micro-organisms non-invasively. With its advantages in biocompatibility, miniaturization, and versatility, the acoustic manipulators presented here will become a powerful tool for many disciplines of science and engineering. The acoustic manipulator device consists of multiple ultrasound transducers electronically driven in an independent fashion. A suspension of microparticles or cells is infused into the cavity. A radio frequency (RF) signal is applied to transducers opposite of each other to generate two acoustic counter propagating waves. The interference of these two series of acoustic propagating waves forms a standing wave, as well as a periodic distribution of pressure nodes (with minimum pressure amplitude) and antinodes (with maximum pressure amplitude) in the medium, causing pressure fluctuations. These fluctuations lead to acoustic radiation forces that act on the suspended particles, moving them to the pressure nodes or antinodes (depending on their mecano elastic properties) in the acoustic standing field. Our acoustic manipulators are capable of manipulating cells and micro-with precision and depending their mechanical properties. Cell viability, proliferation, and apoptosis studies have revealed the technique to be perfectly biocompatible. Additionally, the ability to massively move particles with great speed could make this technique a key tool in many high-throughput assays such as cell sorting and separation. The aforementioned advantages, along with this technique’s simple design and ability to be miniaturized, render the “acoustic manipulator” technique a promising tool for various applications in biology, chemistry, engineering, and materials science.