Acoustofluidic closed-loop control of microparticles and cells using standing surface acoustic waves

Abstract

Precise, automatic and reliable position control of micro-objects such as single particles, biological cells or bio-organisms is critical for applications in biotechnology and tissue engineering. However, conventional acoustofluidic techniques generally lack reliability and automation capability thus are often incapable of building an efficient and automated system where the biological cells need to be precisely manipulated in three dimensions (3D). To overcome these limitations, we developed an acoustofluidic closed-loop control system which is combined with computer vision techniques and standing surface acoustic waves (SSAWs) to implement selective, automatic and precise position control of an object, such as a single cell or microparticle in a microfluidic chamber. Position of the object is in situ extracted from living images that are captured from a video camera. By utilizing the closed-loop control strategy, the object is precisely moved to the desired location in 3D patterns or along designed trajectories by manipulating the phase angle and power signal of the SSAWs. Controlling of breast cancer cells has been conducted to verify the principle and biocompatibility of the control system. This system could be employed to build an automatic system for cell analysis, cell isolation, self-assembling of materials into complex microstructures, or lab-on-chip and organ-on-chip applications.

Acoustofluidic separation enables early diagnosis of traumatic brain injury based on circulating exosomes

“…When cells are in abnormal states-including cells that have undergone malignant transformation, damage, or apoptosis-related changes-their secreted exosomes contain altered protein and molecular signatures 10 . Circulating exosomes found in the blood have been studied as potential targets for the development of blood-based point-of-care diagnostic platforms for cancer 11,12 . Because exosomes are released into circulation, they offer the potential to detect remote lesions.…”

“…Here, we demonstrate an acoustofluidic (a combination of acoustics and microfluidics) 23,24 device as a potential solution for exosome-based TBI diagnosis [25][26][27][28] . The underlying mechanism of acoustofluidics uses acoustic waves to generate acoustic radiation forces on particles in the fluid; the strength of the acoustic radiation force depends on the size and density of the particle 12,[29][30][31][32][33] . The high biocompatibility of acoustofluidic devices also benefits downstream analysis by providing samples with complete structures and components [34][35][36][37][38] .…”

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

“…[ 35,36 ] In addition, we have previously shown that SAW devices are capable of patterning polymer microparticles into 3D matrix structures, [ 15,37 ] as well as precisely and reliably controlling the 3D position of single microparticles and cells. [ 38 ] However, to date, no studies have explored the use of the reusable SAW or acoustofluidic device for rapid 3D patterning of biological objects in scaffold‐based hydrogels contained in a millimeter‐scale microfluidic chamber.…”

Measurement of the Thermal Effect of Standing Surface Acoustic Waves in Microchannel by Fluoresence Intensity

“…Acoustofluidics, which integrates acoustic waves with microfluidics to manipulate particles and fluids in microscale fluid, has been widely used in material engineering [ 1 , 2 , 3 ] and biotechnology [ 4 , 5 ], due to the advantages of noncontact, better biocompatibility, and compactness [ 6 ]. Surface acoustic waves (SAWs), which are generated and propagated on the surface, have attracted attention for the following reasons.…”

“…Researchers found that the SSAWs’ thermal effect is key in the application of acoustofluidics because of the destruction of bio-particles [ 28 ]. To overcome the high temperature in acoustofluidics, cooling equipment had to be integrated into microfluidics [ 6 , 29 ]. However, few have measured the temperature induced by the SSAWs’ thermal effect in the microchannel, which limited the precise controlling and application of particles in the biological detection of SSAW-based devices.…”