Patterning and manipulating microparticles into a three-dimensional matrix using standing surface acoustic waves

Abstract

A method based on standing surface acoustic waves (SSAWs) is proposed to pattern and manipulate microparticles into a three-dimensional (3D) matrix inside a microchamber. An optical prism is used to observe the 3D alignment and patterning of the microparticles in the vertical and horizontal planes simultaneously. The acoustic radiation force effectively patterns the microparticles into lines of 3D space or crystal-lattice-like matrix patterns. A microparticle can be positioned precisely at a specified vertical location by balancing the forces of acoustic radiation, drag, buoyancy, and gravity acting on the microparticle. Experiments and finite-element numerical simulations both show that the acoustic radiation force increases gradually from the bottom of the chamber to the top, and microparticles can be moved up or down simply by adjusting the applied SSAW power. Our method has great potential for acoustofluidic applications, building the large-scale structures associated with biological objects and artificial neuron networks.

3D patterning/manipulating microparticles and yeast cells using ZnO/Si thin film surface acoustic waves

“…where V is the volume of the yeast cell microparticle, g is the gravitational acceleration, y  is the density of the yeast cell microparticle and  is the density of water. The sum of the z component of the radiation forces is a net upward force, which is dependent strongly on the vertical position of the microparticles (i.e., the higher the position, the weaker the force) and input power (i.e., the higher the input power, the higher the force) [1]. When the net upward force is equal to the net downward force, 3D lines of microparticles can form and the height of the 3D patterns can be increased by increasing the input power.…”

“…Shi et al [20] proved that SSAW could be effectively applied to achieve 3D manipulation; however the acoustic radiation force acting in the vertical direction (z direction) is weaker than that acting in the device plane, and the manipulation of microparticles was demonstrated at a vertical range of only 100 μm. Whereas recently we have successfully demonstrated the manipulation in 3D in a vertical range of ~1 mm in the microchamber using the SSAW [1].…”

“…Surface acoustic wave (SAW) devices have recently been extensively investigated for microfluidic applications as they are capable of handling liquid in extremely low volume, manipulating and patterning micro-sized biological objects in liquid precisely and efficiently within microchannels or chambers [1][2][3][4]. The SAW devices are biocompatible, versatile, low-cost, simple in design, contactless, and the manipulation is non-invasive and efficient [1,2,5], making them an extremely attractive choice for manipulation of biological cells. Furthermore, SAW devices based on piezoelectric thin film materials such as ZnO [6] and AlN [7] could be seamlessly integrated into a single lab-on-chip (LOC) device at a low cost [8].…”

Integrating microfluidics and biosensing on a single flexible acoustic device using hybrid modes

“…5h). The demonstrated particle trapping function could be further explored for 3D patterning by increasing the depth of the liquid/droplet for cell patterning applications, 31,32 such as for forming 3D cell networks facilitating neurite growth and guidance, as well as other applications in tissue engineering. This journal is © The Royal Society of Chemistry 2020…”

Large‐Scale Fabrication of 3D Scaffold‐Based Patterns of Microparticles and Breast Cancer Cells using Reusable Acoustofluidic Device

“…[ 1,9 ] Among several approaches to achieve this, the acoustic‐based methods, especially surface acoustic waves (SAWs), have been rapidly developed as a fast, non‐invasive, biocompatible, and contactless technique for manipulating and patterning of cells in microfluidic channels. [ 13–25 ] The current designs of SAW devices require direct bonding of chamber on a piezoelectric substrate, which may cause cross contamination, cell loss, and structure deformation. To overcome this issue, a reusable acoustic tweezers for disposable SAW device has been introduced by adding a coupling liquid layer between a removable, independent polydimethylsiloxane (PDMS)‐glass hybridized microfluidic chamber and the device.…”