On-chip acoustic chaotic micromixer for point-of-care applications

Area of Science:

• Biomedical Engineering
• Microfluidics
• Acoustofluidics

Background:

• Micro-mixing is crucial for miniaturized total analysis systems (μTASs) but current methods lack on-demand activation and efficient analyte capture.
• Challenges exist in ensuring adequate probe particle washing and analyte trapping within microfluidic assays.

Purpose of the Study:

• To develop a novel acoustic chaotic micromixer for integrated sample pretreatment, mixing, analyte trapping, and washing in μTASs.
• To achieve on-demand, chaotic particle mixing and sensitive detection for point-of-care applications.

Main Methods:

• Utilized a Lamb wave resonator (LWR) array to generate acoustic streaming vortices for high-speed microscale mixing.
• Implemented on-demand control of acoustic stimuli for programmable drag force and chaotic particle mixing.
• Integrated the micromixer into a compact cartridge with necessary accessories for a handheld device.

Main Results:

• Demonstrated effective acceleration of particle velocity and enhanced particle-analyte collision via acoustic streaming.
• Achieved chaotic particle mixing by precisely controlling acoustic stimuli from independent LWRs.
• Successfully detected trace amounts of prostate specific antigen (PSA) in fingertip blood samples.

Conclusions:

• The developed acoustofluidic system offers integrated "sample-in-answer-out" capabilities for medical needs.
• The system's compact size, on-chip chaotic mixing, and sensitive detection make it ideal for on-site diagnostics.
• This technology advances point-of-care testing with its efficient and on-demand microfluidic manipulation.