Droplet microfluidics has revolutionized the biomedical and drug development fields by allowing for independent microenvironments to conduct drug screening at the single cell level. However, current ...microfluidic sorting devices suffer from drawbacks such as high voltage requirements (e.g., >200 Vpp), low biocompatibility, and/or low throughput. In this article, a single‐phase focused transducer (SPFT)‐based acoustofluidic chip is introduced, which outperforms many microfluidic droplet sorting devices through high energy transmission efficiency, high accuracy, and high biocompatibility. The SPFT‐based sorter can be driven with an input power lower than 20 Vpp and maintain a postsorting cell viability of 93.5%. The SPFT sorter can achieve a throughput over 1000 events per second and a sorting purity up to 99.2%. The SPFT sorter is utilized here for the screening of doxorubicin cytotoxicity on cancer and noncancer cells, proving its drug screening capability. Overall, the SPFT droplet sorting device shows great potential for fast, precise, and biocompatible drug screening.
Single phase focused transducer (SPFT) is a novel acoustofluidic tool for droplet sorting, using a unique interdigital transducer design. The capability of the SPFT to generate high acoustic intensities enables high efficiency cell‐laden droplet sorting with a low input voltage and a high biocompatibility. This new sorting technology shows significant potential as a tool for droplet‐based screening and analysis.
Acoustofluidics, the fusion of acoustics and microfluidic techniques, has recently seen increased research attention across multiple disciplines due in part to its capabilities in contactless, ...biocompatible, and precise manipulation of micro‐/nano‐objects. Herein, a bimodal signal amplification platform which relies on acoustofluidics‐induced enrichment of nanoparticles is introduced. The dual‐function biosensor can perform sensitive immunofluorescent or surface‐enhanced Raman spectroscopy (SERS) detection. The platform functions by using surface acoustic waves to concentrate nanoparticles at either the center or perimeter of a glass capillary; the concentration location is adjusted simply by varying the input frequency. The immunofluorescence assay is achieved by concentrating fluorescent analytes and functionalized nanoparticles at the center of the microchannel, thereby improving the visibility of the fluorescent output. By modifying the inner wall of the glass capillary with plasmonic Ag nanoparticle‐deposited ZnO nanorod arrays and focusing analytes toward the perimeter of the microchannel, SERS sensing using the same device setup is achieved. Nanosized exosomes are used as a proof‐of‐concept to validate the performance of the acoustofluidic bimodal biosensor. With its sample‐enrichment functionality, bimodal sensing, short processing time, and minute sample consumption, the acoustofluidic chip holds great potential for the development of lab‐on‐a‐chip based analysis systems in many real‐world applications.
Acoustofluidics‐assisted signal amplification platform is introduced to develop bimodal immunofluorescent and surface‐enhanced Raman spectroscop biosensors. The platform functions by using surface acoustic waves to concentrate the target of interest at either the center or perimeter of a glass capillary. Nanosized exosomes are used as a proof‐of‐concept to validate the performance of the acoustofluidic bimodal biosensor.
Efficient isolation and analysis of exosomal biomarkers hold transformative potential in biomedical applications. However, current methods are prone to contamination and require costly consumables, ...expensive equipment, and skilled personnel. Here, we introduce an innovative spaceship-like disc that allows Acoustic Separation and Concentration of Exosomes and Nucleotide Detection: ASCENDx. We created ASCENDx to use acoustically driven disc rotation on a spinning droplet to generate swift separation and concentration of exosomes from patient plasma samples. Integrated plasmonic nanostars on the ASCENDx disc enable label-free detection of enriched exosomes via surface-enhanced Raman scattering. Direct detection of circulating exosomal microRNA biomarkers from patient plasma samples by the ASCENDx platform facilitated a diagnostic assay for colorectal cancer with 95.8% sensitivity and 100% specificity. ASCENDx overcomes existing limitations in exosome-based molecular diagnostics and holds a powerful position for future biomedical research, precision medicine, and point-of-care medical diagnostics.
Acoustic tweezers are a promising technology for the biocompatible, precise manipulation of delicate bioparticles ranging from nanometer-sized exosomes to millimeter-sized zebrafish larva. However, ...their widespread usage is hindered by their low compatibility with the workflows in biological laboratories. Here, we present multifunctional acoustic tweezers that can manipulate bioparticles in a disposable Petri dish. Various functionalities including cell patterning, tissue engineering, concentrating particles, translating cells, stimulating cells, and cell lysis are demonstrated. Moreover, leaky surface acoustic wave-based holography is achieved by encoding required phases in electrode profiles of interdigitated transducers. This overcomes the frequency and resolution limits of previous holographic techniques to control three-dimensional acoustic beams in microscale. This study presents a favorable technique for noncontact and label-free manipulation of bioparticles in commonly used Petri dishes. It can be readily adopted by the biological and medical communities for cell studies, tissue generation, and regenerative medicine.
An acoustofluidic picoinjector Naquin, Ty; Jain, Shivam; Zhang, Jinxin ...
Sensors and actuators. B, Chemical,
11/2024, Letnik:
418
Journal Article
Recenzirano
Droplet microfluidics has emerged as a valuable technology for a multitude of chemical and biomedical applications, offering the capability to create independent microenvironments for high-throughput ...assays. Central to numerous droplet microfluidic applications is the picoinjection of materials into individual droplets, yet existing picoinjection methods often exhibit high power requirements, lack biocompatibility, and/or suffer from limited controllability. Here, we present an acoustofluidic picoinjector that generates acoustic pressure at the droplet interface to enable on-demand, energy-efficient, and biocompatible injection at high precision. We validate our platform by performing acid-base titrations by iteratively injecting picoliter volume reagents into droplets to induce pH transitions detectable by color change in solution. Additionally, we demonstrate the versatility of the acoustofluidic picoinjector in the synthesis of metallic nanoparticles, yielding highly monodisperse and reproducible particle morphologies compared to conventional bulk-phase techniques. By facilitating controlled delivery of reagents or biological samples with unparalleled accuracy, acoustofluidic picoinjection broadens the utility of droplet microfluidics for a myriad of applications in chemical and biological research.
•The acoustofluidic picoinjector can inject reagents into microfluidic droplets with high biocompatibility.•Microfluidic titration can be controlled precisely to facilitate chemical reactions.•Highly uniform metallic nanoparticles can be synthesized for a variety of applications.
Optical imaging with nanoscale resolution and a large field of view is highly desirable in many research areas. Unfortunately, it is challenging to achieve these two features simultaneously while ...using a conventional microscope. An objective lens with a low numerical aperture (NA) has a large field of view but poor resolution. In contrast, a high NA objective lens will have a higher resolution but reduced field of view. In an effort to close the gap between these trade-offs, we introduce an acoustofluidic scanning nanoscope (AS-nanoscope) that can simultaneously achieve high resolution with a large field of view. The AS-nanoscope relies on acoustofluidic-assisted scanning of multiple microsized particles. A scanned 2D image is then compiled by processing the microparticle images using an automated big-data image algorithm. The AS-nanoscope has the potential to be integrated into a conventional microscope or could serve as a stand-alone instrument for a wide range of applications where both high resolution and large field of view are required.
Acoustofluidic Sorters
The cover image depicts the design of an acoustofluidic droplet sorter based on single phase focused transducers. In the droplet sorter, the droplets sequentially flow through ...a tapered channel where an optical fiber pair detects fluorescence signals and then, according to the fluorescence information, pulse acoustic signals are generated to trigger the single‐phase focused transducers. The droplet is manipulated by standing surface acoustic waves and guided to the collection outlet if identified as a cell‐laden droplet. Otherwise, the droplet maintains its route to flow into the waste outlet. More information can be found in article number 2103848 by Tania Konry, Tony Jun Huang, and co‐workers.
Acoustic black holes offer superior capabilities for slowing down and trapping acoustic waves for various applications such as metastructures, energy harvesting, and vibration and noise control. ...However, no studies have considered the linear and nonlinear effects of acoustic black holes on micro/nanoparticles in fluids. This study presents acoustofluidic black holes (AFBHs) that leverage controlled interactions between AFBH-trapped acoustic wave energy and particles in droplets to enable versatile particle manipulation functionalities, such as translation, concentration, and patterning of particles. We investigated the AFBH-enabled wave energy trapping and wavelength shrinking effects, as well as the trapped wave energy-induced acoustic radiation forces on particles and acoustic streaming in droplets. This study not only fills the gap between the emerging fields of acoustofluidics and acoustic black holes but also leads to a class of AFBH-based in-droplet particle manipulation toolsets with great potential for many applications, such as biosensing, point-of-care testing, and drug screening.
PDF
