Surface acoustic wave resonant sensor
阅读说明：本技术 表面声波谐振传感器 (Surface acoustic wave resonant sensor ) 是由 奥尔多·杰索尔卡 基里尔·库斯塔诺维奇 扬切夫 文提斯拉夫·米特科夫 于 2018-05-30 设计创作，主要内容包括：一种用于测量样品的表面声波谐振传感器,包括单端口表面声波(SAW)谐振器,该单端口SAW谐振器包括叉指式换能器(8)和至少一个反射光栅(9)。传感器设置有用于接收样品(20)的区域,所述区域与至少一个反射光栅(9)连通,并且IDT(8)与用于接收样品(20)的所述区域在声学和电气上分开,以使得IDT(8)对样品不质量敏感。该传感器尤其适合于生物感测应用。(A surface acoustic wave resonant sensor for measuring a sample comprises a single port Surface Acoustic Wave (SAW) resonator comprising an interdigital transducer (8) and at least one reflection grating (9). The sensor is provided with a region for receiving a sample (20), said region being in communication with the at least one reflection grating (9), and the IDT (8) is acoustically and electrically separated from the region for receiving the sample (20), such that the IDT (8) is not mass sensitive to the sample. The sensor is particularly suitable for biosensing applications.)
1. A surface acoustic wave resonant sensor (1) for measuring a sample, comprising a single port surface acoustic wave, SAW, resonator, which resonator comprises an interdigital transducer, IDT, (8) and at least one reflection grating (9); wherein the sensor (1) is provided with a region for receiving a sample (20), said region being in communication with the at least one reflection grating (9), and wherein the IDT (8) is acoustically and electrically separated from the region for receiving the sample (20) such that the IDT (8) is not mass sensitive to the sample.
2. A surface acoustic wave resonant sensor (1) according to claim 1, characterized in that the SAW resonator is provided with two reflection gratings (9) arranged on either side of the IDT (8).
3. A surface acoustic wave resonant sensor (1) according to claim 1 or 2, characterized in that the at least one reflection grating (9) is interdigital, such that a capacitor is formed at the interface of the area for receiving the sample and the reflection grating (9).
4. A surface acoustic wave resonant sensor (1) according to claims 1 to 3, characterized in that the at least one reflection grating (9) is adapted to receive low frequency electrical signals from about 10Hz to about 10 MHz.
5. The surface acoustic wave resonant sensor (1) according to any of claims 1 to 4, characterized in that the sensor (1) further comprises a fluidics layer (2) in communication with the SAW resonator, wherein the fluidics layer (2) is provided with a protective cap (5), the protective cap (5) being adapted to inhibit the sample to be measured from entering the IDT (8) such that the sample does not contact the IDT (8).
6. A surface acoustic wave resonant sensor (1) according to any of claims 1 to 5, characterized in that the at least one reflection grating (9) comprises a plurality of thin film members (91) arranged periodically and substantially parallel to each other.
7. A surface acoustic wave resonant sensor (1) according to claim 6, characterized in that the plurality of thin film members (91) of the reflection grating are arranged at a pitch of half the wavelength of the surface acoustic wave at resonance.
8. A surface acoustic wave resonant sensor (1) according to any of claims 5 to 7, characterized in that the fluidic layer (2) further comprises at least one microfluidic chamber (3), the at least one microfluidic chamber (3) being arranged in communication with the at least one reflection grating (9) such that the area for receiving a sample (20) is formed by the at least one microfluidic chamber (3).
9. The surface acoustic wave resonant sensor (1) of any one of claims 5 to 8, characterized in that the protective cap (5) in the fluid layer (2) is provided with a recess such that an air gap is formed above the IDT (8).
10. A surface acoustic wave resonant sensor (1) according to any of claims 1 to 9, characterized in that the SAW resonator is arranged on the first surface (7) of the piezoelectric substrate (6).
11. A surface acoustic wave resonant sensor (1) according to any of claims 1 to 10, characterized in that an intermediate layer (11) is provided between the first surface (7) of the piezoelectric substrate (6) and the SAW resonator.
12. A surface acoustic wave resonant sensor (1) according to any of claims 1 to 11, characterized in that the SAW resonator employs in particular SH-SAW and/or leaky SAW propagating along the X-axis of the piezoelectric substrate, which is selected from one of the following: y-cut LiNbO3, 36 ° Y-cut LiNbO3, 41 ° Y-cut LiNbO3, 64 ° Y-cut LiNbO3, 163 ° Y-cut LiNbO3, 36 ° Y-cut LiTaO3, 42 ° Y-cut LiTaO 3.
13. A surface acoustic wave resonant sensor (1) according to any of claims 1 to 12, characterized in that the sample is a liquid sample.
14. A sensor assembly comprising a plurality of surface acoustic wave resonant sensors (1) according to any of claims 1 to 13.
15. The sensor assembly according to claim 14, characterized in that the sensor assembly comprises a single fluid layer (2).
16. A method for physical, biological and/or physical measurement, comprising:
-providing a sample to be tested to a surface acoustic wave resonant sensor (1) according to any of claims 1 to 13,
-providing a high frequency signal of more than about 100MHz to the IDT (8) and/or a low frequency signal of about 10Hz to about 10MHz to the at least one reflection grating (9),
-measuring at least one of: shifts in the resonant frequency, amplitude changes in admittance and conductance near resonance, phase changes in admittance near resonance, changes in the attenuation time of the resonator signal, and/or changes in the complex resistance of the SAW resonator.
17. The method according to claim 16, wherein a high frequency signal is provided to the IDT (8) and a low frequency signal is provided to the at least one reflection grating (9) concurrently.
18. A system for measuring a sample, comprising:
-a surface acoustic wave resonant sensor (1) according to any of claims 1 to 13,
-a high frequency electrical signal generator for providing high frequency signals of more than about 100MHz to the IDT (8),
-a low frequency electrical signal generator for providing a low frequency electrical signal from about 10Hz to about 10MHz to the at least one reflection grating (9).
Technical Field
The present disclosure relates to surface acoustic wave sensors suitable for chemical, biological, or physical sensor applications. In particular, the present disclosure relates to a surface acoustic wave resonant sensor including a single port Surface Acoustic Wave (SAW) resonator.
Background
Chemical, biological, and physical sensing involves the determination of the detectable presence, concentration, or quantity of a given chemical or biochemical analyte, biological entity, or physical stimulus. Chemical or biochemical analytes include, but are not limited to, organic and inorganic molecules. Biological entities include, but are not limited to, microorganisms, biological cells, subcellular structures, and biological tissues. Physical stimuli include, but are not limited to, a change in mass, a change in pressure, a change in elasticity, a change in viscosity, a change in density, or a change in electrical properties.
The most common resonant acoustic wave biosensor is a Quartz Crystal Microbalance (QCM), which provides single port frequency measurements in the range of about 10MHz or lower. Quartz Crystal Microbalances (QCMs) use thickness shear bulk acoustic waves (thickness shear bulk acoustic wave) in thin quartz plates. The sensing event occurs on the electrical ground surface of the plate, while the opposite plate surface and its signal electrodes are completely isolated from the liquid. In other previously developed examples in the context of integrated sensor arrays with operating frequencies up to the GHz frequency range, high frequency alternatives for QCM were proposed, which employ ZnO and AlN films with tilted c-axis orientation ("Recent developments of membrane electro-acoustic technology for biosensor applications" by i.katardjiev and v.yantchev), "Vacuum",
Surface-emitting acoustic wave devices can be used to detect and quantify numerous measurements by means of perturbations in the electrical and mechanical properties of the device caused by an analyte, biological entity or physical stimulus to be measured.
The classical implementation of shear surface acoustic wave (SH-SAW) biosensors is a delay line configuration as found in US 6378370B 1 (Sensor research and development, Sensor Res and dev Corp, 2002, 04/30) and US 7716986B 2 (institute of industrial technology, 2010, 5/18). The delay line biosensor includes a piezoelectric substrate. The first input SAW transducer excites the SAWs. A second SAW transducer, positioned a defined distance from the input SAW transducer along the SAW propagation axis, receives the transmitted SAW and converts the acoustic signal back to an electrical signal. Both SAW transducers are protected from the high dielectric constant and conductivity of the liquid by a protective cap/layer. The sensor response can be expressed either as a shift in SAW delay time, a shift in transmission loss, as a phase shift between the exciting SAW transducer and the receiving SAW transducer, or as a combination of the above.
SH-SAW delay line biosensors are characterized by large insertion losses (i.e., strong signal losses in transmission) due to significant SH-SAW attenuation in the liquid matrix along the delay path between the two SAW transducers. The longer the delay path, the stronger the attenuation. Another source of loss is the bi-directionality of classical SAW interdigital transducers (IDTs).
In an attempt to simplify sensor measurements, liquid phase Sensors with a two-port resonant topology have been proposed (Surface Acoustic Wave (SAW) Resonators for monitoring trim Film Formation, by s. hohmann et al., "Surface Acoustic Wave (SAW) Resonators for monitoring trim Film Formation)", Sensors (Sensors),
Plate guided modes including shear plate acoustic mode (SHAPM), Flexural Plate Wave (FPW), lowest order symmetric (S0), and anti-symmetric (A0) lamb wave are also applicable to the design of single port resonant sensors operating in liquid environments. The plate geometry itself allows a natural separation between the transducer and the liquid environment by using two opposite plate faces for transduction and sensing, respectively (T. Mirea et al, "underfluence of liquid properties on the performance of S0-mode Lamb wave sensors II: Experimental Validation" of liquid properties on the performance of S0 mode Lamb wave sensors, Sensors and Actuators B (Sensors and Actuators B), Vol. 229, p. 331-337, 2016).
Due to the benefits compared to earlier developments, single port SAW resonant sensor topologies suitable for in-liquid sensing and mass production are of high value for the development of miniature and robust biochemical sensor applications.
Disclosure of Invention
Accordingly, the present invention preferably seeks to mitigate, alleviate or eliminate one or more of the above-identified deficiencies in the art and disadvantages singly or in any combination and solves at least the above-identified problems by providing a surface acoustic wave resonant sensor for measuring a sample, comprising a single port Surface Acoustic Wave (SAW) resonator comprising an interdigital transducer (IDT) and at least one reflection grating. The sensor is provided with a region for receiving a sample, said region being in communication with at least one reflection grating. The IDT is acoustically and electrically separated from the region for receiving the sample, so that the IDT is not mass sensitive to the sample. The sensor is particularly suitable for biosensing applications.
A sensor assembly is also provided.
A system for measuring a sample is also provided.
Furthermore, a method for physical, biological and/or physical measurement is provided.
Further advantageous embodiments are disclosed in the appended and dependent patent claims.