Integrated ZnO Film Based Acoustic Wave Microfluidics and Biosensors

2010 ◽  
Vol 67 ◽  
pp. 49-58 ◽  
Author(s):  
Jack K. Luo ◽  
Y.Q. Fu ◽  
Greg Ashley ◽  
Williams I. Milne
Keyword(s):  
Acoustic Wave ◽  
Acoustic Waves ◽  
Low Cost ◽  
Surface Acoustic Waves ◽  
Acoustic Streaming ◽  
Film Surface ◽  
High Sensitivity ◽  
Zno Film ◽  
Actuation Mechanism ◽  
Saw Devices

Lab-on-a-chip (LOC) is one of the most important microsystems with promising applications in microanalysis, drug development and diagnosis, etc. We have been developing a LOC biodetection system using acoustic wave as a single actuation mechanism for both microfluidics and biosensing using low cost piezoelectric ZnO film. Surface acoustic waves (SAW) coupled into the liquid will induce acoustic streaming, or move the droplet on the surface. These have been utilized to make SAW-based micropumps and micromixers which are simple in structure, easy to fabricate, low cost, reliable and efficient. SAW devices and thin film bulk acoustic resonators (FBAR) have been fabricated on nanocrystalline ZnO thin films deposited using sputtering on Si substrates. A streaming velocity up to ~5cm/s within a microdroplet and a droplet moving speed of ~1cm/s have been achieved. SAW based droplet ejection and vaporization have also been realized. SAW devices and FBARs have been used to detect antibody/antigen and rabbit/goat immunoglobulin type G molecules, showing their high sensitivity. The results have demonstrated the feasibility of using a single actuation mechanism for the LOC.

ZnO Thin Film Surface Acoustic Wave based Lab-on-a-Chip

2009 ◽  
Vol 1222 ◽  
Author(s):  
Jack Luo ◽  
Yongqing Richard Fu ◽  
Xiaoye Du ◽  
Daesik Lee ◽  
Sung Maeng ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Acoustic Waves ◽  
Acoustic Streaming ◽  
Film Surface ◽  
Lab On A Chip ◽  
Single Chip ◽  
Si Substrates ◽  
Actuation Mechanism ◽  
Main Components

AbstractLab-on-a-chip (LOC) is one of the most important microsystem applications with promise for use in microanalysis, drug development, diagnosis of illness and diseases etc. LOC typically consists of two main components: microfluidics and sensors. Integration of microfluidics and sensors on a single chip can greatly enhance the efficiency of biochemical reactions and the sensitivity of detection, increase the reaction/detection speed, and reduce the potential cross-contamination, fabrication time and cost etc. However, the mechanisms generally used for microfluidics and sensors are different, making the integration of the two main components complicated and increases the cost of the systems. A lab-on-a-chip system based on a single surface acoustic wave (SAW) actuation mechanism is proposed. SAW devices were fabricated on nanocrystalline ZnO thin films deposited on Si substrates using sputtering. Coupling of acoustic waves into a liquid induces acoustic streaming and motion of droplets. A streaming velocity up to ˜5cm/s and droplet pumping speeds of ˜1cm/s were obtained. It was also found that a higher order mode wave, the Sezawa wave is more effective in streaming and transportation of microdroplets. The ZnO SAW sensor has been used for prostate antigen/antibody biorecognition systems, demonstrated the feasibility of using a single actuation mechanism for lab-on-a-chip applications.

X-ray diffraction from perfect silicon crystals distorted by surface acoustic waves

2000 ◽  
Vol 33 (4) ◽  
pp. 1019-1022 ◽  
Author(s):  
R. Tucoulou ◽  
R. Pascal ◽  
M. Brunel ◽  
O. Mathon ◽  
D. V. Roshchupkin ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Acoustic Waves ◽  
Crystal Surface ◽  
Source Region ◽  
Surface Acoustic Waves ◽  
X Ray Diffraction ◽  
Zno Film ◽  
Near Surface ◽  
X Ray

High-resolution X-ray diffraction measurements were carried out on ZnO/Si devices under surface acoustic wave excitation and revealed some very clear satellite diffraction peaks that are obtained from the sinusoidal modulation of the near-surface region. This experiment shows that the propagation of a Rayleigh surface acoustic wave in a perfect crystal acts as a dynamical diffraction grating. The variation of the acoustic velocity has been followed across the crystal surface from the acoustic source region (beneath the ZnO film) to the far field region (not covered by the ZnO film).

SURFACE ACOUSTIC WAVE INDUCED OPTICAL EFFECTS IN A NEMATIC LIQUID CRYSTAL

1993 ◽  
Vol 07 (17) ◽  
pp. 1167-1171
Author(s):  
A. K. GEORGE
Keyword(s):  
Liquid Crystal ◽  
Theoretical Model ◽  
Acoustic Wave ◽  
Nematic Liquid Crystal ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Acoustic Streaming ◽  
Crystal Film ◽  
Optical Effects ◽  
Wave Induced

The optical changes occurring in a homeotropically aligned nematic liquid crystal film when excited by surface acoustic waves have been studied. Striped domains at low acoustic intensities followed by acoustic streaming at high intensities have been observed. The increase in transparency of the oriented liquid crystal film under the action of surface acoustic waves also has been investigated. The experimental results compare favourably with the available theoretical model based on the effect of rotation of the plane of polarization.

High Harmonic Surface Acoustic Wave Devices for Harsh Environment Sensor Applications

2013 ◽  
Vol 1519 ◽  
Author(s):  
J. Justice ◽  
M. Elbaz ◽  
L. E. Rodak ◽  
D. Korakakis
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Low Cost ◽  
High Harmonic ◽  
High Sensitivity ◽  
Harsh Environments ◽  
Device Performance ◽  
Quality Factors ◽  
Vehicle Exhaust ◽  
Saw Devices

ABSTRACTSurface acoustic wave (SAW) devices are ideal candidates for gas sensors due to their small size, low cost of production and high sensitivity. Increasing restrictions on pollution and emissions create the necessity for sensors that can operate in the harsh environments found in vehicle exhaust systems and industrial production. Gallium nitride (GaN) is a robust, chemically inert, piezoelectric semiconductor, making it an attractive material for SAW devices designed to detect and monitor gases in harsh environments. In this work, SAW devices designed to operate at the 5th and 7th harmonics are fabricated on GaN thin films and their performance is measured through insertion loss, signal to noise ratio, operating frequency and quality factor. Devices are directly exposed to the exhaust gas of a common diesel engine. Device performance is then re-measured and compared. SAW devices fabricated in this work have measured operating frequencies above 1 GHz, and quality factors up to and higher than 2000, depending on the harmonic mode. SAW devices on GaN showed good chemical stability and measured changes in device performance after exhaust exposure was negligible.

WIRELESS SAW IDENTIFICATION AND SENSOR SYSTEMS

2000 ◽  
Vol 10 (04) ◽  
pp. 1143-1191 ◽  
Author(s):  
F. SCHMIDT ◽  
G. SCHOLL
Keyword(s):  
Acoustic Wave ◽  
Electromagnetic Interference ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Sensor Systems ◽  
Extreme Temperatures ◽  
Industrial Equipment ◽  
Design Rules ◽  
Saw Sensor ◽  
Saw Devices

Identification and sensor systems based on surface acoustic waves exhibit intriguing properties which have hitherto remained unexploited by semiconductor-based systems. They offer a long readout distance of up to more than 20 meters with purely passive surface acoustic wave (SAW) devices. SAW devices operate with no battery or wiring, withstand extreme temperatures and work reliably and maintenance-free over many decades even in harsh industrial environments. Because they operate at frequencies in the GHz range, SAW identification and sensor systems are well protected from the electromagnetic interference that often occurs in the vicinity of industrial equipment such as motors and high-voltage lines. The fundamentals and design rules of numerous passive wireless SAW sensor and identification systems for industrial and domestic applications as well as relevant practical work will be presented.

The size dependant behaviour of particles driven by a travelling surface acoustic wave (TSAW)

Lab on a Chip ◽  
2018 ◽  
Vol 18 (24) ◽  
pp. 3926-3938 ◽  
Author(s):  
Armaghan Fakhfouri ◽  
Citsabehsan Devendran ◽  
Asif Ahmed ◽  
Julio Soria ◽  
Adrian Neild
Keyword(s):  
Particle Size ◽  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Sound Source ◽  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Acoustic Streaming

Travelling surface acoustic waves (TSAW) can cause particles to follow the swirling patterns of acoustic streaming, collect in lines or migrate away from the sound source, this paper examines how particle size determines which one of these behaviours occur.

scholarly journals Mechanisms and Applications of Neuromodulation Using Surface Acoustic Waves—A Mini-Review

2021 ◽  
Vol 15 ◽  
Author(s):  
Danli Peng ◽  
Wei Tong ◽  
David J. Collins ◽  
Michael R. Ibbotson ◽  
Steven Prawer ◽  
...  
Keyword(s):  
Acoustic Waves ◽  
Surface Acoustic Waves ◽  
Acoustic Streaming ◽  
Ultrasound Transducers ◽  
Self Heating ◽  
Saw Devices ◽  
Heating Effects ◽  
Neuroscience Research ◽  
Neuronal Stimulation ◽  
Limited Frequency

The study of neurons is fundamental for basic neuroscience research and treatment of neurological disorders. In recent years ultrasound has been increasingly recognized as a viable method to stimulate neurons. However, traditional ultrasound transducers are limited in the scope of their application by self-heating effects, limited frequency range and cavitation effects during neuromodulation. In contrast, surface acoustic wave (SAW) devices, which are producing wavemodes with increasing application in biomedical devices, generate less self-heating, are smaller and create less cavitation. SAW devices thus have the potential to address some of the drawbacks of traditional ultrasound transducers and could be implemented as miniaturized wearable or implantable devices. In this mini review, we discuss the potential mechanisms of SAW-based neuromodulation, including mechanical displacement, electromagnetic fields, thermal effects, and acoustic streaming. We also review the application of SAW actuation for neuronal stimulation, including growth and neuromodulation. Finally, we propose future directions for SAW-based neuromodulation.

Characterization of RF Sputtered ZnO Piezoelectric Films Using Transmission Electron Microscope

1975 ◽  
Vol 33 ◽  
pp. 86-87
Author(s):  
Kemining W. Yeh ◽  
Richard S. Muller ◽  
Wei-Kuo Wu ◽  
Jack Washburn
Keyword(s):  
Integrated Circuit ◽  
Acoustic Waves ◽  
New Technology ◽  
Surface Acoustic Waves ◽  
Electromechanical Properties ◽  
Leading Role ◽  
Saw Devices ◽  
Transmission Electron ◽  
High Degree

Considerable and continuing interest has been shown in the thin film transducer fabrication for surface acoustic waves (SAW) in the past few years. Due to the high degree of miniaturization, compatibility with silicon integrated circuit technology, simplicity and ease of design, this new technology has played an important role in the design of new devices for communications and signal processing. Among the commonly used piezoelectric thin films, ZnO generally yields superior electromechanical properties and is expected to play a leading role in the development of SAW devices.

scholarly journals Formation of a Complex Topologies of SAW-Based Inertial Sensors by Laser Thin Film Local Evaporation

Micromachines ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 10
Author(s):  
Alexander Kukaev ◽  
Dmitry Lukyanov ◽  
Denis Mikhailenko ◽  
Daniil Safronov ◽  
Sergey Shevchenko ◽  
...  
Keyword(s):  
Thin Film ◽  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Acoustic Waves ◽  
Inertial Sensors ◽  
Surface Acoustic Waves ◽  
Sensing Element ◽  
Small Series ◽  
Evaporation Technique ◽  
Photolithography Process

Originally, sensors based on surface acoustic waves are fabricated using photolithography, which becomes extremely expensive when a small series or even single elements are needed for the research. A laser thin film local evaporation technique is proposed to substitute the photolithography process in the production of surface acoustic wave based inertial sensors prototypes. To estimate its potential a prototype of a surface acoustic wave gyroscope sensing element was fabricated and tested. Its was shown that the frequency mismatch is no more than 1%, but dispersion of the wave on small inertial masses leads to a spurious parasitic signal on receiving electrodes. Possible ways of its neglecting is discussed.

scholarly journals Visualization of Surface Acoustic Waves in Thin Liquid Films

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
R. W. Rambach ◽  
J. Taiber ◽  
C. M. L. Scheck ◽  
C. Meyer ◽  
J. Reboud ◽  
...  
Keyword(s):  
Liquid Film ◽  
Acoustic Waves ◽  
Low Cost ◽  
Thin Liquid Film ◽  
Surface Acoustic Waves ◽  
Liquid Films ◽  
Theoretical Description ◽  
Propagation Path ◽  
Microfluidic Channels ◽  
Potential Applications

Abstract We demonstrate that the propagation path of a surface acoustic wave (SAW), excited with an interdigitated transducer (IDT), can be visualized using a thin liquid film dispensed onto a lithium niobate (LiNbO3) substrate. The practical advantages of this visualization method are its rapid and simple implementation, with many potential applications including in characterising acoustic pumping within microfluidic channels. It also enables low-cost characterisation of IDT designs thereby allowing the determination of anisotropy and orientation of the piezoelectric substrate without the requirement for sophisticated and expensive equipment. Here, we show that the optical visibility of the sound path critically depends on the physical properties of the liquid film and identify heptane and methanol as most contrast rich solvents for visualization of SAW. We also provide a detailed theoretical description of this effect.

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