An official website of the United States government
Heating of surface acoustic wave (SAW) devices can be utilized for micro-heating and in microreactor applications, but is a disadvantage in biosensing. In this contribution, we fabricate SAW devices in 128° YX LiNbO3 and ST X quartz substrates with same physical dimensions, having center frequencies approximately of 96 MHz and 78 MHz, respectively to study heating at several power levels. We demonstrate droplet heating is caused by acoustic wave streaming resulting from the coupling between fluid and solid. A 10 μm water droplet on a 128° YX LiNbO3 device can be heated up by 3.3 °C with 15 dbm power level, whereas, the ST X quartz device is only heated up by 0.7°C. Our work illustrates that the 128° YX LiNbO3 substrate shows great potential for liquid heating applications. The ST quartz substrate is better suited for removal of non-specifically bound (NSB) proteins in biosensing applications, especially if shear horizontal SAWs propagating in the orthogonal direction are utilized for biosensing.
more »
« less
Orthogonal Surface Acoustic Wave (SAW) Sensor for Cancer Biomarker Detection with Accelerated Binding Kinetics
A device incorporating both Rayleigh wave and shear horizontal surface acoustic waves is made on a ST-Quartz substrate. The Rayleigh wave induced microfluidic mixing shows effects on accelerating the binding kinetics of real-time sensing between antibody and antigen, which is measured by phase change from the shear horizontal surface acoustic wave direction on the ST-Quartz. Preliminary results on this device show shortened response time and enhanced phase signal when the binding is accelerated by microfluidic streaming from the Rayleigh wave. The device can be fabricated using a low cost, single step photolithography method and can be combined with a small electronic sensor for data readout, which allows for a variety of surface-based biomarker detections on a portable platform. In this work, detection of Carcinoembryonic antigen (CEA) binding with functionalized capture antibody is studied to show the effects of mass loading amplification due to Rayleigh wave microfluidic streaming.
more »
« less
- Award ID(s):
- 2108795
- PAR ID:
- 10414781
- Date Published:
- Journal Name:
- 2022 IEEE Sensors
- Page Range / eLocation ID:
- 1 to 3
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Acoustic streaming has been widely used in microfluidics to manipulate various micro−/nano-objects. In this work, acoustic streaming activated by interdigital transducers (IDT) immersed in highly viscous oil is studied numerically and experimentally. In particular, we developed a modeling strategy termed the “slip velocity method” that enables a 3D simulation of surface acoustic wave microfluidics in a large domain (4 × 4 × 2 mm 3 ) and at a high frequency (23.9 MHz). The experimental and numerical results both show that on top of the oil, all the acoustic streamlines converge at two horizontal stagnation points above the two symmetric sides of the IDT. At these two stagnation points, water droplets floating on the oil can be trapped. Based on these characteristics of the acoustic streaming field, we designed a surface acoustic wave microfluidic device with an integrated IDT array fabricated on a 128° YX LiNbO 3 substrate to perform programmable, contactless droplet manipulation. By activating IDTs accordingly, the water droplets on the oil can be moved to the corresponding traps. With its excellent capability for manipulating droplets in a highly programmable, controllable manner, our surface acoustic wave microfluidic devices are valuable for on-chip contactless sample handling and chemical reactions.more » « less
-
Rizzo, Piervincenzo; Su, Zhongqing; Ricci, Fabrizio; Peters, Kara J (Ed.)Anisotropic collagen-based biomaterials have gained significant attention in the fields of tissue engineering and regenerative medicine. They have shown great potential for wound dressing, corneal grafting, and exploring the mechanism of cancer cell invasion. Various external physical field-based methods for the fabrication of anisotropic collagen-based biomaterials have been developed, including electrospinning, microfluidic shearing, mechanical loading, and so on. In this study, we put forward an acoustic streaming-based method that uses acoustic wave-induced fluid streaming to control collagen self-assembly and fiber arrangement. Our acoustic device leverages a piezoelectric transducer to generate traveling acoustic waves in fluids, and the wave-fluid interaction further induces fluid streaming, known as acoustic streaming. If the fluid contains collagen macromolecules, the acoustic streaming is able to affect the collagen self-assembly process to create biomaterials containing directionally arranged collagen fibers along the streaming velocity direction. Therefore, this acoustic streaming-based method allows for manufacturing collagen hydrogel layers that contain acoustically arranged collagen fibers and have controlled anisotropic material properties. We performed a series of proof-of-concept experiments by using a fabricated acoustic device to control the self-assembly process of collagens loaded in a Petri dish. Our results show the effectiveness of arranging collagen fibers that follow the flow direction of acoustic streaming. To better understand the collagen manipulation mechanism, we used particle image velocimetry to characterize the acoustic wave-induced fluid streaming. We expect this study can contribute to the fabrication of collagen-based anisotropic biomaterials for biomedical applications.more » « less
-
In this article, we demonstrate an acoustofluidic device for cell lysis using the acoustic streaming effects induced by acoustically oscillating sharp-edged structures. The acoustic streaming locally generates high shear forces that can mechanically rupture cell membranes. With the acoustic-streaming-derived shear forces, our acoustofluidic device can perform cell lysis in a continuous, reagent-free manner, with a lysis efficiency of more than 90% over a range of sample flow rates. We demonstrate that our acoustofluidic lysis device works well on both adherent and non-adherent cells. We also validate it using clinically relevant samples such as red blood cells infected with malarial parasites. Additionally, the unique capability of our acoustofluidic device was demonstrated by performing downstream protein analysis and gene profiling without additional washing steps post-lysis. Our device is simple to fabricate and operate while consuming a relatively low volume of samples. These advantages and other features including the reagent-free nature and controllable lysis efficiency make our platform valuable for many biological and biomedical applications, particularly for the development of point-of-care platforms.more » « less
-
Abstract Distributed acoustic sensing (DAS) provides dense arrays ideal for seismic tomography. However, DAS only records average axial strain change along the cable, which can complicate the interpretation of surface-wave observations. With a rectangular DAS array located in the City of Oxnard, California, we compare phase velocity dispersion at the same location illuminated by differently oriented virtual sources. The dispersion curves are consistent for colinear and noncolinear virtual sources, suggesting that surface-wave observations in most of the cross-correlations are dominated by Rayleigh waves. Our measurements confirm that colinear channel pairs provide higher Rayleigh-wave signal-to-noise ratio (SNR). For cross-correlations of noncolinear channel pairs, the travel time of each connecting ray path can still be obtained despite the lower SNR of Rayleigh wave signals. The inverted Rayleigh-wave dispersion map reveals an ancient river channel consistent with the local geologic map. Our results demonstrate the potential of DAS-based 2D surface-wave tomography without special treatment of directional sensitivity in areas where one type of wave is dominating or can be identified.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/SENSORS52175.2022.9967354
