Substrates for SAW Sensor Research

LiNbO3 Wafers for SAW Sensor Research

A government lab researcher requested a quote for the following:

We would like to obtain information of in stock Lithium Niobate wafers, 128 degree Y-Cut, with a diameter 4 inch (100 mm) and a 2.0 mm thickness or greater.

Our objective is to fabricate Surface Acoustic Wave (SAW) units with the wafers we obtain.

We would like to obtain information such in Table form on the availability of

Lithium Niobate wafers, 128 degree Y-Cut, with a diameter 4 inch (100 mm) and a thickness 2.0 mm thickness or greater, single side polished preferred; however both sides polished may be acceptable.
Could you provide a table or items that are currently in stock and could be shipped immediately (overnight) with approximate cost? I believe we would order 4 or more wafers.

I have also heard of Black Lithium Niobate and was told it had the same piezoelectric properties.

Do you have Black Lithium Niobate wafers that would satisfy this request? If so, please list these in Table form as requested above.

Please Refereence #25557 for specs/pricing.

Get Your Quote FAST!

Your Name:

Company:

Your email:

Your message:

Some common substrates used in saw sensors include:

Quartz - Quartz is a popular substrate for saw sensors because of its high piezoelectric coupling coefficient, low temperature coefficient, and stable performance over a wide temperature range. It is often used in high-frequency applications.
Lithium tantalate (LiTaO3) - LiTaO3 is another popular substrate for saw sensors. It has a high piezoelectric coupling coefficient, low insertion loss, and good temperature stability.
Lithium niobate (LiNbO3) - LiNbO3 is a substrate that has similar properties to LiTaO3, but it is less expensive. It is often used in low-frequency applications.
Langasite (La3Ga5SiO14) - Langasite is a substrate that has a high temperature stability and good chemical resistance. It is often used in harsh environments.
Sapphire - Sapphire is a substrate that has high mechanical stability, high thermal conductivity, and good optical properties. It is often used in high-temperature applications.

The choice of substrate depends on the specific application of the saw sensor and the desired performance characteristics.

What is a SAW Sesor?

Lithium niobate is an important material in the development of SAW sensors. The material has high electrical conductivity, high resistance to corrosion, and excellent insulating properties. It can be used in a variety of applications, including electronics, medical equipment, and even military equipment.

Phononic band structure engineering

If you are looking for ways to improve the performance of your SAW sensors, then you might want to consider using Lithium Niobate phononic band structure engineering. This type of fabrication method can provide you with a high-confinement resonator with low mechanical loss.

The acoustic wavelength of piezoelectric solids is extremely small at 1 GHz. However, the effect of a waveguide layer on the acoustic band structure of a phononic crystal device is not completely understood. It is important to study this issue thoroughly. A phononic crystal is a piezoelectric crystal that consists of a layer of waveguide deposited on a substrate.

Phononic crystals are based on their high sensitivity to external stimuli. When placed on a piezoelectric substrate, they can be used to control the opening of acoustic band gaps. Besides, they can also be used to measure the density of liquid that is filling some parts of the structure.

Surface acoustic wave resonators are known for their good electrical transduction and low dissipation. Although these devices are not cheap, they have great integrability and are used in a variety of applications. Because of this, they are attractive candidates for modern electronic devices. Moreover, their low losses and high integrability make them suitable for use in mobile telecommunication systems.

To design a periodic phononic crystal with a waveguide layer, you need to know its acoustic band structure. By doing so, you can adjust the period of the grooves to generate a SAW cavity. You can then fine-tune the period of the central cavity to align the fundamental mode to the center of the PnC bandgap.

As a result, you can then design a SAW sensor with a very small wavelength and high bandwidth. Additionally, you can obtain a high quality factor RF-filter, which is necessary for RF communications. In addition, you can design a high-fQ small-mode SAW resonator to achieve quantum phononics. These technologies can also enable integrated hybrid systems.

To design a SAW resonator, you need to have a conductive substrate with a suitable electrical and acoustic conductivity. You can then apply a thin film of ScxAl1-xN or sapphire to enhance the acoustic velocity of the device.

Q factors and coupling strength

Surface acoustic waves (SAW) are important in communications and data processing applications. The resonant frequency of SAWs is in the range of 4-12 GHz. There are a number of devices that utilize SAWs, including integrated optical waveguides. These devices have attracted a great deal of attention. In this paper, the effect of proton exchange on electromechanical coupling coefficient of lithium niobate (LiNbO3) substrates is investigated. It is shown that the initial growth in K2 value may be attributed to the changes in the electrical potential distribution of the SAW.

During the proton exchange, a substantial change in the crystal structure occurs. This translates into a reduction of the electromechanical coupling coefficient. Furthermore, the presence of a non-piezoelectric layer on the piezoelectric substrate reduces the contribution of the piezoelectric effect.

Depending on the propagation direction, the amplitude of emitted SAWs is decreased. For example, the maximum amplitude of a resonator with d = 0.3 lSAW/2 is larger than that of a spring-coupled resonator.

An isotropic piezo coupling is preferable to maximize the focusing effect. The X-direction piezo coupling is 6 times stronger than the orthogonal direction in the SAW plane. However, the focusing pattern is weaker.

The amplitude of SAWs is further reduced with increasing distance d. This is because the eigenfrequencies of f+- and Q+- are periodically modulated. A phase-shifting of the modulation is also observed.

Electromechanical coupling is also observed to decrease with increasing d. This is because the eigenfrequencies f+- and Q+- are phase-shifted by p/2. Thus, this model is able to describe the experimental data quite well. Moreover, it can explain the modifications of the quality factors.

However, there is a need for further optimization of the fabrication process. In this paper, the effect of proton-exchange on the electromechanical coupling coefficient is studied in several Y-cut and Z-cut LiNbO3 samples. Several different crystal cuts have been calculated to provide accurate K2 values. Lastly, an acoustic microscope and acousto-optic diffraction technique have been used to study the velocity of acoustic waves.

The SAW interdigital transducer has been studied at 80 MHz in Z-cut substrates. At cryogenic temperatures, the resonator with patterned Bragg mirrors has reached a Q-factor of 106.

Effects of random noise on SAW device and loop's amplifier

A SAW delay line magnetic field sensor can be operated in an open loop or closed loop configuration. This article presents a brief introduction to the device as well as its electrical and magnetic properties. It then presents sections discussing the magnetic field and phase noise related to its magnetostrictive layer. The sensor was tested at two different frequencies and power levels.

First, a typical SAW device is operated at a synchronous frequency of 144.8 MHz. It is then subjected to various input power levels to measure the random phase fluctuations. At +24 dBm, the stress level is 100 MN/m.sup.2, while at +10 dBm, the return loss is better than 20 dB at each port.

Secondly, an electronic readout system is used to obtain an output in the form of the phase-stable numerically controlled oscillator. It is then fed by a control signal V.sub.c and upconverted to the passband of the device.

The second phase-stable circuit has an input and an output and is coupled to a loop amplifier. It is then further coupled to a loop signal sampling circuit. Similarly, the output is coupled to a loop gain adjustment circuit. These components are then coupled to a signal path 31d.

The loop is then coupled to a single sideband upconverter that suppresses the undesired lower sideband. In addition, a small loop gains adjustment circuit is used to set the proper loop gain conditions. As with the oscillator, the psCL(t) has been calculated to be the best of its kind.

Finally, a comparison of the phase-stable numerically controlled device with the Mini-Circuits ZFL-1000LN+ is presented. Although the device is similar in design, it has an improved flicker phase noise coefficient. Using this device, the white phase noise was shown to decrease by a factor of 10 with increasing input power.

Likewise, the SAW delay line magnetic field sensor was found to have an insertion loss of better than 20 dB at each port. However, the true insertion-loss-to-frequency ratio is not known. Nevertheless, the SAW delay line sensor was found to have a group delay of 0.5 ppm, which is not bad for an instrument that is designed to operate at ambient static magnetic flux densities of 0 mT.

Applications

Lithium niobate is a ferroelectric material that exhibits high K$sp2$ values. It is ideal for nonlinear optical polarization. Its refractive properties make it useful for various spectroscopic applications. The low electrical conductivity of lithium niobate makes it ideal for SAW-based sensing.

A study was conducted to develop a microfluidic SAW sensor that detects C-reactive protein (CRP) concentrations. This research used a single channel SAW resonator with a 4-mm wide and 1-mm thick substrate. Mass variations on the sensing surface were measured and the amplitude of the shift in the amplitude peak was correlated with the concentration of CRP. At a detection limit of 4 ng/mL, the sensitivity was sufficient to perform a clinical diagnosis.

The resonator was studied with atomic force microscopy (AFM) and transmission-mode microwave impedance microscopy (TMIM). A dark area is located at the center of the device. On the side, bright areas of metal IDTs are visible. An etched groove is visible.

Using COMSOL multiphysics software, transient analyses and voltage-based responses of the sensing structures were calculated. Moreover, finite element analysis was performed to simulate the devices. The results showed a good confinement of the SAW.

Among the key electrode configurations, interdigitated electrode transducers (IDTs) are necessary to achieve electromechanical coupling. In order to design a sensor with a suitable frequency, the length of IDTs must be parallel to the propagation direction of the surface wave.

Various types of SAW-based temperature sensors have been designed. These devices use aluminum or copper electrodes. They are operated at a variety of frequencies, from 2 MHz to 4 MHz.

Compared with semiconductor materials, lithium niobate has lower electrical conductivity. This allows it to be used for low-insertion loss SAW devices. Besides, it has higher Q factors. Higher Q factors are associated with better confinement of the SAW.

These devices can be printed on nonpiezoelectric substrates, such as silicon or glass. However, it is important to ensure precise process control for extreme cleanliness. Also, the presence of shorts between the lines can impede performance.

SAW sensors are increasingly being used in chemical and mechano-biological applications. Further improvements in the development of these sensors may occur in the future.

Lithium Niobate to develop SAW sensors

Lithium niobate (LiNbO3) is a piezoelectric material that is commonly used in the development of surface acoustic wave (SAW) sensors. SAW sensors are devices that use surface acoustic waves (SAWs) to detect and measure various physical phenomena, such as temperature, pressure, and humidity.

LiNbO3 is a suitable material for SAW sensors because it has a strong piezoelectric effect, meaning that it can generate an electric charge in response to applied mechanical stress. This property allows LiNbO3 to be used to generate and detect SAWs on its surface.

In SAW sensors, LiNbO3 is typically used in the form of a thin crystal layer that is patterned with interdigital transducers (IDTs). The IDTs are used to generate and detect the SAWs, which propagate along the surface of the LiNbO3 crystal. When the SAW encounters an object or substance being measured, it is perturbed in a way that can be detected by the IDTs, allowing the sensor to measure the physical property of interest.

SAW sensors based on LiNbO3 are used in a variety of applications, including temperature sensing, pressure sensing, humidity sensing, and chemical sensing. They are known for their high sensitivity, stability, and longevity, making them useful in a range of industries including automotive, aerospace, and healthcare.

How do saw sensors work?

Saw sensors are devices that are used to detect the presence or absence of objects in a specific area or zone. They are commonly used in manufacturing and automation applications to help control the movement of machinery or to trigger alarms or other actions when certain objects or conditions are detected.

There are several different types of saw sensors, but most of them operate using some form of electromagnetic field. For example, inductive saw sensors use a coil of wire to create an electromagnetic field around a sensing area. When a metal object enters this field, it disrupts the field and causes a change in the sensor's output. This change can be detected by the sensor's electronics and used to trigger an action or send a signal to another device.

Capacitive saw sensors work in a similar way, but they use a capacitor (an electrical component that stores electrical charge) to create an electromagnetic field. When an object enters this field, it changes the capacitance of the capacitor, which can be detected by the sensor's electronics.

There are also other types of saw sensors that use different principles to detect the presence or absence of objects. For example, some saw sensors use lasers or infrared light to detect the presence of objects, while others use ultrasound or mechanical mechanisms to detect movement or changes in position.

Overall, saw sensors are useful tools for detecting and reacting to the presence or absence of objects in a specific area or zone, and they are widely used in a variety of applications across many industries.

How does a surface acoustic wave sensor work?

A surface acoustic wave (SAW) sensor is a device that uses the physical properties of sound waves to detect and measure various types of stimuli, such as temperature, pressure, humidity, and the presence or absence of certain substances.

SAW sensors work by generating and detecting surface acoustic waves, which are sound waves that travel along the surface of a solid material. These waves are generated by a piezoelectric transducer, which converts electrical signals into mechanical vibrations and vice versa. The transducer sends a high-frequency electrical signal through a thin layer of piezoelectric material, which causes the material to vibrate and generate a surface acoustic wave.

The wave travels along the surface of the material and is reflected back to the transducer when it reaches the end of the material or encounters an object or substance. The transducer is then able to detect the reflected wave and measure the time it takes for the wave to travel back to the transducer.

The time it takes for the wave to travel back to the transducer is related to the properties of the object or substance that the wave encounters. For example, if the wave encounters a temperature change, it will be affected by the change in temperature and the time it takes for the wave to travel back to the transducer will be different than if the wave encountered a different temperature.

SAW sensors are able to detect and measure these changes in the wave's travel time, and use this information to determine the properties of the object or substance that the wave encountered. They are commonly used in a variety of applications, including temperature sensing, pressure sensing, and chemical sensing.

What are five types of acoustic sound sensors?

Microphone: A microphone is a type of acoustic sound sensor that converts sound waves into an electrical signal. Microphones are commonly used to capture and amplify sound, and are found in a wide range of applications, including telephone systems, recording studios, and musical instruments.
Ultrasonic sensor: An ultrasonic sensor is a type of acoustic sound sensor that uses high-frequency sound waves to measure distance, speed, or the presence of objects. Ultrasonic sensors are commonly used in robotics, automation, and security systems.
Surface acoustic wave (SAW) sensor: A surface acoustic wave (SAW) sensor is a type of acoustic sound sensor that uses surface acoustic waves to detect and measure various types of stimuli, such as temperature, pressure, and humidity. SAW sensors are commonly used in temperature sensing, pressure sensing, and chemical sensing applications.
Piezoelectric sensor: A piezoelectric sensor is a type of acoustic sound sensor that uses piezoelectric materials to detect and measure mechanical stress or pressure. Piezoelectric sensors are commonly used in a variety of applications, including force sensing, vibration sensing, and impact sensing.
Laser Doppler velocimeter: A laser Doppler velocimeter is a type of acoustic sound sensor that uses laser light to measure the velocity of objects or substances. Laser Doppler velocimeters are commonly used in flow measurement and velocity sensing applications.

What is a surface acoustic wave biosensor?

A surface acoustic wave (SAW) biosensor is a type of sensor that uses surface acoustic waves to detect and measure the presence or concentration of specific biological substances in a sample. SAW biosensors are commonly used in a variety of applications, including medical diagnosis, environmental monitoring, and food safety testing.

SAW biosensors work by generating and detecting surface acoustic waves, which are sound waves that travel along the surface of a solid material. These waves are generated by a piezoelectric transducer, which converts electrical signals into mechanical vibrations and vice versa. The transducer sends a high-frequency electrical signal through a thin layer of piezoelectric material, which causes the material to vibrate and generate a surface acoustic wave.

SAW biosensors are able to detect and measure changes in the wave's travel time that are caused by the presence or concentration of specific biological substances in the sample. These changes can be used to determine the presence or concentration of the substances in the sample.

SAW biosensors are highly sensitive and are able to detect extremely small amounts of biological substances. They are also relatively fast and can provide results in a matter of minutes or even seconds. However, they can be somewhat complex and require specialized equipment to operate.

What Substrates are Used to Fabricate Saw Sensors?

There are various types of substrates that are used to fabricate saw sensors. These include One-port resonators, composite substrates, and chemical sensors. It is also important to note that some of these substrates are only suitable for certain applications. For example, acoustic plate mode sensors are designed for use in shear-horizontal environments.

Composite substrates

SAW sensors are used in a wide variety of applications. They provide a high level of sensitivity, stability, and selectivity. As well, they are very light. These characteristics make them ideal for use in medical and aerospace fields. However, they have limited flexibility. This has prompted SAW sensor fabricators to develop composite substrates.

In the past, most SAW sensors were fabricated on rigid piezoceramic substrates. However, this method does not offer adequate adaptability and low vibration sensitivity. By using piezoelectric-on-silicon (POS) substrates, the volume and weight of the SAW sensor can be minimized. Also, the POS substrate can improve energy conversion efficiency.

In this thesis, we present a flexible piezocomposite SAW sensor. It is fabricated by incorporating a composite substrate and interdigital transducers. For this purpose, a finite element analysis model was developed to study the influence of structural parameters on SAW propagation characteristics. The model was verified by experimental results.

The piezoelectric thin film is affixed to the POS substrate. The thickness of the piezoelectric thin film is directly related to the SAW wavelength and the amount of dispersion of surface waves. The piezoelectric crystal material is preferably crystallographically matched to the base.

In order to achieve optimum performance, the surface roughness of the POS substrate is reduced to a minimum. Optimum cancellation requires a substantially equal insertion loss and initial frequency.

A POS substrate is obtained by implementing a hot-pressing process. During the hot-pressing process, a non-polar a phase of a crystal is transformed to a polar b crystalline phase. The a-phase crystal is dissolved in a mixture of N, N- dimethyl sulfoxide and PVDF polymer. Nanoparticles of PZT ceramics are then added in the 0-3 direction. This increases the strength and flexibility of the piezoelectric thin film.

Besides, the POS substrate is bonded by using a protective layer containing vanadium 131. This protective layer provides a hermetic seal to the packaged SAW device. To provide space between the inner surfaces of the SAW device, a glass frit seal is also employed.

Compared with conventional devices, SAW sensors are much lighter. They also have a high sensitivity and good response time.

One-port resonators

Resonator devices are used to fabricate saw sensors. Typically, SAW devices are fabricated on piezoelectric substrates. This type of device is composed of input or output interdigital transducers (IDTs), shorted metal electrodes and reflectors on both sides. The reflectors are designed to minimize losses by containing acoustic waves in the cavity.

The performance of a SAW device is typically degraded at higher frequencies. However, there are novel, creative techniques to integrate RF-SAW resonators with commercial RF-CMOS processes. These techniques provide lower costs and increased quality factors.

For a two-port CMOS SAW resonator, the input and output interdigital transducers are fabricated on a single CMOS chip. These IDTs are then stacked to form a reflector structure. A 1.8 mm thick liquid photoresist mask is then used to block the resonator area.

After the CMOS SAW resonators are fabricated, an equivalent circuit model is developed to describe the two-port resonator. Based on measurements, the values for the quality factor, array reflectivity (G) and transmission coefficient (TC) were calculated. In order to analyze the results, a thermal camera was placed on top of the device. Using WinTes software, the thermal image was recorded.

Standard IC processing techniques can be used to fabricate nm wide IDTs for a resonator. This process is called reactive ion etching. Unlike conventional etching, this method removes oxide between the interdigital transducer fingers.

Traditionally, RF-SAW resonators were fabricated using full custom fabrication steps. However, with CMOS technology, resonator designs are now available in minimum sizes. Moreover, a higher quality factor is achieved by combining the benefits of CMOS with RF-CMOS.

CMOS resonators are fabricated using a 0.18 mm IBM RF-CMOS process. The resonators are characterized by a resonant frequency of 1.15 GHz.

RF-CMOS SAW resonators are also characterized by a higher quality factor. Compared to conventional CMOS SAW resonators, RF-CMOS devices have a Q factor of 285". They are also capable of achieving resonant frequencies of up to 3.12 GHz.

These advantages make CMOS resonators a feasible alternative to micromachined MEMS structures. CMOS technology is also highly precise. Compared to full custom fabrication, a resonator with a resolution of 0.9 micron can be fabricated. Lastly, CMOS SAW resonators reduce insertion and acoustic wave losses.

Shear-horizontal acoustic plate mode sensors

The substrates used to fabricate shear-horizontal acoustic plate mode sensors include piezoelectric substrates and waveguide material. These substrates may be rigid or non-piezoelectric. It depends on the design of the device.

Shear-horizontal surface acoustic plate mode (SHP) devices are designed to detect chemical substances. A piezoelectric crystal layer, a thin waveguide layer, and a transducer make up the sensing component. This combination offers a highly linear phase response, and minimal propagation losses.

A Love wave sensor has been developed to perform multi-analyte detection in real time. It consists of a piezoelectric substrate and an interdigital transducer. A delay-line configuration is a preferred option. In addition to its capability of detecting pathogenic microorganisms, the sensor can be field deployable.

Shear-horizontal surface polarized PAW have been reported in the literature. They are characterized by asymmetric DS12(s) curves, which have wider components for conductive liquids. To measure the conductivity of a conductive liquid, the acoustic wavelength is enlarged and the operating frequency is reduced. However, the sensitivity of the sensor depends on the position of the liquid on the plate and the material of the waveguide.

Shear-horizontal acoustic plates are also useful for measuring temperature. Their advantages over surface acoustic waves are the lower phase velocity and high acoustic-to-electrical attenuation. An interdigital transducer is required to separate the acoustic plate modes from the opposite side.

An interdigital transducer is typically made of 1000 nanometer thick Al. The guiding layer is also made of thin Al. Optimal thickness of the guiding layer is determined by the desired operating frequency and sensitivity. As the thickness of the guiding layer increases, the signal is attenuated.

Shear-horizontal SHP devices can be manufactured using a simple fabrication method. A piezoelectric crystal layer is deposited on a rigid substrate. The thickness is then normalized to match the acoustic wavelength. By applying oscillating electric fields, a mechanical wave is generated.

Acoustic measurements of the conductivity of a liquid are a popular choice, especially when the temperature is constant. For example, a NaCl water solution has a conductivity of 6 S/m. When the temperature is changed, acoustic measurements have a higher accuracy.

Chemical sensors based on viscoelastic properties

Chemical sensors are devices used to measure the concentration of a chemical substance in a sample. They have several limitations. These limitations include dimensional scale, sensitivity, and selectivity. Generally, the sensor must be able to detect 10-9 molar concentrations. It must also be portable and economically affordable. In addition, it must have high selectivity. The amount of selectivity required depends on the type of analyte.

One important determinant of selectivity is the thickness of the coating. Increased coating thickness increases frequency noise and deteriorates the sensor's limit of detection. An analytical expression for viscoelastic losses was developed and used to identify an optimum coating thickness.

Another factor influencing selectivity is the coupling between the surface acoustic wave field and the film overlay. Several authors have modeled the interaction of the SAW and the film in the past.

Using multiharmonic QCM, researchers investigated the viscoelastic properties of sensing layers. Specifically, they determined the changes in resonant frequency with the presence of bacterial colonies. Moreover, they analyzed the effect of dissipation. Their results showed that the frequency decreased at a lower value than what was expected based on the dimension of the bacteria.

For the aptamer-based sensors, a layer of neutravidin covered the surface of a QCM transducer. This monolayer chemisorbed to the gold surface of the transducer. A portion of the results were presented at the 1st International Electronic Conference.

In general, the viscoelastic properties of the sensing layer depend on the interaction of the analyte with the film. Analyzed viscoelastic properties may provide information about the freedom of movement of the molecules. Alternatively, it can also give information about the crosslinking bonds in the sensing layer.

In addition to the effects of resonant frequency, changes in the mass of the sensing layers affect the sensor's response. Analyzing the changes in mass can lead to estimates of the viscoelastic properties of the surface layer at the piezocrystal.

Viscoelastic properties of the sensing layers can also be studied using higher harmonics. The Kelvin-Voigt viscoelastic model is a useful tool for this purpose. However, it predicts large differences in the coefficient of viscosity.