Ethanol concentration detection system

Abstract

An ethanol concentration detection system relates to the field of ethanol concentration detection. The problem that miniaturization and high-performance detection of an existing ethanol sensor cannot be considered at the same time is solved. Sensitive elements (interdigital capacitors) are ingeniously integrated at specific angular points of a quadrupole moment sensing topology circuit, high-sensitivity, high-selectivity and high-robustness detection of ethanol concentration, miniaturization of an ethanol sensor and high-performance detection are achieved, and a novel normal form is provided for design of a high-performance chemical sensor. The method is mainly used for ethanol concentration detection.

Description

Ethanol Concentration Detection System Technical Field

[0001] This invention relates to the field of ethanol concentration detection. Background Technology

[0002] Ethanol sensors have wide applications in traffic safety, industrial production, and environmental monitoring. Currently, the mainstream ethanol sensors mainly fall into two categories: semiconductor metal-oxide type and electrochemical type. Although these technologies are relatively mature, they still have significant shortcomings in terms of selectivity, stability, and power consumption.

[0003] Patent document CN112255198A discloses a semiconductor ethanol sensor based on tin dioxide (SnO2). This type of sensor measures ethanol by detecting the change in resistance caused by the oxidation of ethanol on a metal oxide surface, offering advantages such as low cost and high sensitivity. However, a significant drawback of this technology is its poor gas selectivity. Since the SnO2 surface responds to various volatile organic compounds (such as acetone, methanol, and formaldehyde), inaccurate measurement results are easily caused, especially in complex atmospheres or applications with interfering gases. Furthermore, this type of sensor typically operates at high temperatures of 300-400°C, which not only leads to high power consumption but also accelerates the aging of the sensitive material, affecting the long-term stability of the sensor.

[0004] Another patent document, CN113281399A, relates to an electrochemical ethanol sensor. It employs the principle of a fuel cell, detecting concentration by measuring the current generated during the oxidation of ethanol on a catalytic electrode. Compared to semiconductor-type sensors, it offers improved selectivity and lower power consumption. However, this technology has inherent drawbacks: firstly, the internal liquid or gel electrolyte may dry out or leak, leading to sensor performance degradation or even failure, and a limited lifespan; secondly, the catalytic electrode is susceptible to poisoning and deactivation by substances such as sulfides and siloxanes in the environment; and thirdly, its output signal is significantly affected by ambient temperature and humidity, requiring complex compensation in the circuitry or algorithm.

[0005] Furthermore, both semiconductor and electrochemical sensors currently face the challenge of balancing miniaturization and high-performance detection. With the development of emerging fields such as the Internet of Things and wearable devices, even more stringent requirements are being placed on sensors for low power consumption, small size, and high reliability, all of which current technologies have limitations in. These issues urgently need to be addressed. Summary of the Invention

[0006] The purpose of this invention is to solve the problem that existing ethanol sensors cannot simultaneously achieve miniaturization and high-performance detection. This invention provides an ethanol concentration detection system.

[0007] The ethanol concentration detection system includes an impedance analyzer, interdigitated capacitors, a quadrupole moment sensing topology circuit, and a processing unit.

[0008] Interdigitated capacitors are used to sense the concentration of ethanol to be measured;

[0009] The concentration of ethanol to be measured causes a change in the capacitance of the interdigital capacitor, which in turn causes a change in the resistance of the grounding capacitor in the quadrupole moment sensing topology circuit connected in parallel with the interdigital capacitor. This causes the output node of the quadrupole moment sensing topology circuit to output a changing current, which is then sent to the impedance analyzer.

[0010] The impedance analyzer generates a curve of the output node impedance to ground as a function of frequency based on the received changing current.

[0011] The processing unit is used to extract the frequency at the peak of the impedance to ground from the curve and calculate the frequency at the peak and the standard frequency. Frequency offset Then, by combining the preset linear relationship between the frequency offset and the ethanol concentration, the current frequency offset is obtained. The corresponding ethanol concentration is used as the concentration of the ethanol to be tested.

[0012] Preferably, the interdigital capacitor is placed as a sensing element in a petri dish containing the ethanol to be tested.

[0013] Preferably, the quadrupole moment sensing topology circuit is divided into 36 modules, and the 36 modules form a 6×6 matrix. The 36 modules are respectively 1 module 1, 4 modules 2, 1 module 3, 4 modules 4, 16 modules 5, 4 modules 6, 1 module 7, 4 modules 8 and 1 module 9.

[0014] Module 1 includes an inductor to ,capacitance to and two negative resistance units; where,

[0015] capacitance One end is connected to one end of the two negative resistance units, and the capacitor. one end and One end of the capacitor and one end of the interdigitated capacitor are connected simultaneously, and the capacitor... The other end is connected to the inductor One end of the capacitor one end and capacitor One end is connected simultaneously.

[0016] The other end of the interdigitated capacitor is connected to the other end of the first negative resistance unit, and the capacitor... The other end, capacitor The other end, inductor The other end is also connected to the power ground;

[0017] The other end of the first negative resistor unit is connected to the inductor. One end of the capacitor One end of the inductor one end and capacitor One end is connected simultaneously, inductor The other end is connected to the capacitor The other end and the inductor One end of the capacitor is connected to the power supply ground; The other end is connected to the capacitor The other end, capacitor one end and capacitor One end is connected simultaneously;

[0018] inductance The other end, capacitor The other end, capacitor The other end and capacitor The other end is designated as port 1 to port 4 respectively;

[0019] And capacitor All are used as grounding capacitors in the quadrupole moment sensing topology circuit. One end is connected to the data signal input terminal of the impedance analyzer as the output node of the quadrupole moment sensing topology circuit.

[0020] Module 2 includes inductors to and capacitors to ,in,

[0021] inductance One end is connected to the capacitor one end and inductor One end is connected simultaneously, inductor The other end is connected to the inductor One end of the inductor One end of the capacitor one end and inductor One end is simultaneously connected to the power ground;

[0022] capacitance The other end is connected to the inductor The other end, capacitor one end and capacitor One end is connected simultaneously;

[0023] inductance The other end is connected to the capacitor One end of the inductor One end of the inductor The other end and capacitor The other end is connected simultaneously;

[0024] capacitance The other end is connected to the capacitor The other end, inductor The other end, capacitor one end and capacitor One end is connected simultaneously;

[0025] inductance One end of the inductor The other end, inductor The other end, capacitor The other end, capacitor The other end and capacitor The other end is designated as port 5 to port 10 respectively;

[0026] Module 3 includes an inductor to Among them, inductance One end of the inductor one end and inductor The other end is connected to the power ground, and the inductor One end and the other end are designated as port 11 and port 12, respectively.

[0027] Module 4 includes an inductor to and capacitors to ;in,

[0028] inductance One end is connected to the capacitor one end and capacitor One end of the capacitor is connected simultaneously. The other end is connected to the inductor One end of the capacitor one end and inductor One end is also connected to the power ground;

[0029] capacitance The other end is connected to the capacitor One end of the capacitor one end and inductor The other end is connected simultaneously;

[0030] inductance The other end is connected to the capacitor One end of the capacitor The other end and the inductor One end of the capacitor is connected simultaneously. The other end is connected to the capacitor The other end, inductor The other end and capacitor one end and capacitor One end is connected simultaneously;

[0031] inductance One end of the capacitor One end of the inductor The other end, capacitor The other end, capacitor The other end and capacitor The other end is designated as port 13 to port 18 respectively;

[0032] Module 5 includes an inductor to and capacitors to ;in,

[0033] inductance One end is connected to the capacitor one end and capacitor One end of the capacitor is connected simultaneously. The other end is connected to the inductor One end of the capacitor one end and capacitor One end is connected simultaneously, inductor The other end is connected to the inductor One end of the capacitor one end and inductor One end is simultaneously connected to the power ground;

[0034] inductance The other end is connected to the inductor The other end, capacitor The other end, capacitor one end and inductor One end of the capacitor is connected simultaneously. The other end is connected to the capacitor The other end, inductor The other end, capacitor one end and capacitor One end is connected simultaneously;

[0035] inductance One end of the inductor The other end, inductor The other end, capacitor The other end, capacitor One end of the capacitor The other end and capacitor The other end is designated as ports 19 to 25 respectively;

[0036] Module 6 includes an inductor to and capacitors to ;in,

[0037] inductance One end is connected to the capacitor One end is connected to the inductor. The other end is connected to the inductor one end and capacitor One end of the capacitor is connected simultaneously. The other end is connected to the capacitor The other end is also connected to the power ground;

[0038] inductance One end of the inductor The other end and the inductor The other end is designated as ports 26 to 28 respectively;

[0039] Module 7 includes capacitors to Among them, capacitors One end of the capacitor is connected to the power supply ground. The other end is connected to the capacitor One end is connected and used as port 29, capacitor The other end is designated as port 30;

[0040] Module 8 includes an inductor to and capacitors to ;in,

[0041] capacitance One end is designated as port 31;

[0042] capacitance The other end is connected to the capacitor one end and inductor One end is connected simultaneously and used as port 32;

[0043] capacitance The other end is connected to the inductor One end is connected and used as port 33;

[0044] inductance The other end and the inductor The other end is also connected to the power ground;

[0045] Module 9 includes an inductor to and capacitors to ;in,

[0046] capacitance One end is connected to the capacitor One end is connected and used as port 34; capacitor The other end is connected to the capacitor One end is connected to the capacitor. The other end is connected to the inductor The other end and the inductor One end is connected simultaneously, inductor The other end is connected to the power ground;

[0047] capacitance The other end is connected to the inductor One end is connected and used as port 35;

[0048] Four modules 2 are connected in series. In any two adjacent modules 2, ports 9 and 10 of the current module 2 are connected to ports 5 and 6 of the next module 2, respectively. The four modules 2 are defined as the first to the fourth modules 2, and ports 5 and 6 of the first module 2 are connected to ports 4 and 3 of the first module 2, respectively. Ports 9 and 10 of the fourth module 2 are connected to ports 11 and 12 of the third module 3, respectively.

[0049] Four modules of type 4 are connected in series. In any two adjacent modules of type 4, ports 15 and 16 of the current module of type 4 are connected to ports 13 and 14 of the next module of type 4, respectively. The four modules of type 4 are defined as the first to the fourth modules of type 4, and ports 13 and 14 of the first module of type 4 are connected to ports 1 and 2 of the first module of type 4, respectively. Ports 15 and 16 of the fourth module of type 4 are connected to ports 29 and 30 of the seventh module of type 7, respectively.

[0050] Four modules of type 6 are connected in series. In any two adjacent modules of type 6, port 28 of the current module of type 6 is connected to port 26 of the next module of type 6. The four modules of type 6 are defined as the first to the fourth modules of type 6, and port 26 of the first module of type 6 is connected to port 12 of the third module of type 3, and port 28 of the fourth module of type 6 is connected to port 35 of the ninth module of type 9.

[0051] Four modules of type 8 are connected in series. In any two adjacent modules of type 8, port 34 of the current module of type 8 is connected to port 31 of the next module of type 8. The four modules of type 8 are defined as the first to the fourth modules of type 8, and port 31 of the first module of type 8 is connected to port 30 of the seventh module of type 7, and port 33 of the fourth module of type 8 is connected to port 34 of the ninth module of type 9.

[0052] Sixteen No. 5 modules form a 4×4 array. The four No. 5 modules in each row of the array are connected in series. In any two adjacent No. 5 modules, ports 24 and 25 of the current No. 5 module are connected to ports 19 and 20 of the next No. 5 module, respectively. The four No. 5 modules in each row are defined as the first to the fourth No. 5 modules.

[0053] Ports 19 and 23 of the first to fourth modules 5 in the first row are connected to ports 7 and 8 of the first to fourth modules 5, respectively.

[0054] Ports 19 to 21 of the first 5th module in rows 1 to 4 are connected to ports 17, 18 and 16 of the first to fourth 4th modules, respectively.

[0055] Ports 24 and 25 of the fourth module 5 in rows 1 to 4 are connected to ports 26 and 27 of the fourth module 6 in rows 1 to 4, respectively.

[0056] Ports 21 and 22 of the first to fourth 5th modules in the fourth row are connected to ports 31 and 33 of the first to fourth 8th modules, respectively.

[0057] Preferably, the negative resistance unit includes a resistor. to ,inductance and operational amplifier ;

[0058] operational amplifier non-inverting input terminal and resistor After one end is connected, it serves as one end of the negative resistance unit;

[0059] operational amplifier The inverting input terminal and the resistor one end and resistor One end is connected at the same time, resistor The other end is connected to the inductor One end is connected to the inductor. The other end serves as the other end of the negative resistance unit;

[0060] resistance The other end is connected to the operational amplifier Output terminal and resistor The other end is connected simultaneously.

[0061] Preferably, the capacitor , , , , , and The capacitance values ​​are all ;

[0062] capacitance , , , , and The capacitance values ​​are all ,and This is the topology strength coefficient;

[0063] capacitance The capacitance value is ;

[0064] capacitance All capacitance values ​​are ,and This is the standard capacitance coefficient.

[0065] Preferably, an inductor , , , , and The sensitivity values ​​are all ;

[0066] inductance , , , , , , The sensitivity values ​​are all ,and This is the topology strength coefficient;

[0067] capacitance , , , and The sensitivity values ​​are all ;

[0068] inductance Sensitivity value ,inductance Sensitivity value ,inductance Sensitivity value .

[0069] Preferably, .

[0070] Preferably, .

[0071] The beneficial effects of this invention are:

[0072] The working principle of this invention is to utilize the extreme sensitivity of boundary states (corner states) in the topology circuit to boundary disturbances, as well as the robustness brought by topology protection.

[0073] 1. Formation of topological angle states: When circuit parameters satisfy... At that time, the system is in a topologically nontrivial phase, and under open boundary conditions, its energy spectrum is at the standard frequency. A topological state localized in a corner will appear, corresponding to an extremely high impedance peak to ground at the output node.

[0074] 2. Signal transmission and sensing mechanisms:

[0075] Physical quantity conversion: Change in ethanol concentration → Change in the capacitance of the interdigital capacitor ( ).

[0076] Signal transmission: capacitance change ( Perturbed boundary conditions of the topology circuit → cause a shift in the characteristic frequency of the topology's "angle state". ).

[0077] Signal reading: Monitor the frequency shift of the impedance peak at the output node using an impedance analyzer. → Through linear relationships Calculate the change in ethanol concentration.

[0078] 3. Robustness: Due to the protection of topological symmetry, the existence of angular states is independent of minute perturbations within the crystal lattice. Even if the capacitance of non-nodes is perturbed by up to 60%, the angular state frequency remains stable for the measured... Response ( The parameters also remain almost unchanged, ensuring the stability of the sensor in complex environments.

[0079] 4. Enhanced performance:

[0080] High sensitivity: Sensitivity up to approximately 38 Hz / fF, and this can be further improved by reducing the unit inductance. and capacitor Further improvements.

[0081] High quality factor: By compensating for the parasitic resistance of the inductor with a negative resistance unit, the system's quality factor Q is effectively improved, resulting in a sharper impedance peak and facilitating accurate frequency measurement.

[0082] The ethanol concentration detection system described in this invention does not aim to miniaturize bulky traditional instruments, but rather reconstructs the entire sensing mechanism into an "intelligent frequency scale on a chip." Its core is the direct coupling of a highly integrated miniature interdigital capacitor into an on-chip quadrupole moment sensing topology circuit also fabricated using planar technology. The negative resistance unit integrated on the chip actively cancels out losses, ensuring that the topological angular resonance peak determined by the quadrupole moment retains extremely high sharpness even after miniaturization. In this way, the measured signal of ethanol concentration change is converted into a precise "twist" of the frequency of this extremely sharp and stable topological resonance peak. Ultimately, this invention condenses the detection performance of a miniaturized quadrupole moment sensing topology circuit into an idealized interdigital capacitor that is extremely insensitive to disturbances and highly sensitive only to the target parameter, thus achieving a physical balance between miniaturization and maximization of performance indicators such as detection sensitivity and anti-interference capability.

[0083] The design of quadrupole moment sensing topology circuits utilizes the theory of higher-order topological insulators to construct a circuit system with symmetry-protected angular states, which is the foundation for achieving highly robust sensing.

[0084] Angular frequency shift detection mechanism: The change in dielectric constant caused by the analyte (ethanol) is converted into the characteristic frequency shift of the topological boundary state for reading, and the sensitivity is much higher than that of traditional capacitive sensors.

[0085] Active compensation technology for negative resistance units: By introducing negative resistance, the influence of the inherent parasitic resistance of the inductor is effectively offset, significantly improving the system quality factor, thereby enhancing signal resolution and detection accuracy.

[0086] Selective sensitivity and global robustness: The quadrupole moment sensing topology design enables only disturbances to the sensitive unit to be effectively detected, while it has strong immunity to disturbances in other parts of the circuit (such as component aging and environmental fluctuations), which is a direct manifestation of topology protection.

[0087] The invention achieves high sensitivity, high selectivity, and high robustness in the detection of ethanol concentration by ingeniously integrating the sensitive element (interdigital capacitor) at a specific corner of the quadrupole sensing topology circuit, while simultaneously taking into account the miniaturization of the ethanol sensor and high-performance detection, providing a novel paradigm for the design of high-performance chemical sensors. Attached Figure Description

[0088] Figure 1 is a schematic diagram of the ethanol concentration detection system of the present invention;

[0089] Figure 2 is a diagram showing the distribution of the modules in the quadrupole moment sensing topology circuit;

[0090] Figures 3 to 11 are schematic diagrams of the circuit principles of modules 1 to 9, respectively.

[0091] Figure 12 is a schematic diagram of the circuit structure of the load unit;

[0092] Figure 13 is a partial schematic diagram of region A in Figure 1;

[0093] Figure 14 is a partial schematic diagram of region B in Figure 1;

[0094] Figure 15 is a partial schematic diagram of region C in Figure 1;

[0095] Figure 16 is a partial schematic diagram of region D in Figure 1. Detailed Implementation

[0096] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0097] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0098] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0099] Specific Implementation Method 1: This implementation method is described with reference to Figure 1. The ethanol concentration detection system described in this implementation method includes an impedance analyzer, interdigitated capacitors, a quadrupole moment sensing topology circuit, and a processing unit.

[0100] Interdigitated capacitors are used to sense the concentration of ethanol to be measured;

[0101] The concentration of ethanol to be measured causes a change in the capacitance of the interdigital capacitor, which in turn causes a change in the resistance of the grounding capacitor in the quadrupole moment sensing topology circuit connected in parallel with the interdigital capacitor. This causes the output node of the quadrupole moment sensing topology circuit to output a changing current, which is then sent to the impedance analyzer.

[0102] The impedance analyzer generates a curve of the output node impedance to ground as a function of frequency based on the received changing current.

[0103] The processing unit is used to extract the frequency at the peak of the impedance to ground from the curve and calculate the frequency at the peak and the standard frequency. Frequency offset Then, by combining the preset linear relationship between the frequency offset and the ethanol concentration, the current frequency offset is obtained. The corresponding ethanol concentration is used as the concentration of the ethanol to be tested.

[0104] The ethanol concentration detection system described in this embodiment achieves high sensitivity, high selectivity, and high robustness in ethanol concentration detection by cleverly integrating a sensitive element (interdigital capacitor) at a specific corner of a quadrupole moment sensing topology circuit, providing a novel paradigm for the design of high-performance chemical sensors. In application, the interdigital capacitor is placed as the sensing element within a petri dish containing the ethanol to be measured. Standard frequency. This represents the frequency corresponding to an ethanol concentration of 0.

[0105] When ethanol solutions of different concentrations flow through an interdigitated capacitor acting as a sensing element, it causes a change in the capacitance value. The interdigitated capacitor is connected in parallel with the ground capacitance in the topology circuit, so changes in capacitance directly alter the capacitance to ground of the corner node (i.e., the output node of the topology circuit). According to perturbation theory, the characteristic frequency of the corner state is extremely sensitive to this change. An increase in this frequency leads to a linear decrease in the peak impedance frequency. By monitoring this frequency shift, highly sensitive detection of ethanol concentration can be achieved.

[0106] Referring to Figure 2, the specific structure of the quadrupole moment sensing topology circuit is further shown. The quadrupole moment sensing topology circuit is divided into 36 modules, and the 36 modules form a 6×6 matrix. The 36 modules are 1 module 1, 4 modules 2, 1 module 3, 4 modules 4, 16 modules 5, 4 modules 6, 1 module 7, 4 modules 8 and 1 module 9.

[0107] Referring to Figure 3, module 1 includes an inductor. to ,capacitance to and two negative resistance units; where,

[0108] capacitance One end is connected to one end of the two negative resistance units, and the capacitor. one end and One end of the capacitor and one end of the interdigitated capacitor are connected simultaneously, and the capacitor... The other end is connected to the inductor One end of the capacitor one end and capacitor One end is connected simultaneously;

[0109] The other end of the interdigitated capacitor is connected to the other end of the first negative resistance unit, and the capacitor... The other end, capacitor The other end, inductor The other end is also connected to the power ground;

[0110] The other end of the first negative resistor unit is connected to the inductor. One end of the capacitor One end of the inductor one end and capacitor One end is connected simultaneously, inductor The other end is connected to the capacitor The other end and the inductor One end of the capacitor is connected to the power supply ground; The other end is connected to the capacitor The other end, capacitor one end and capacitor One end is connected simultaneously;

[0111] inductance The other end, capacitor The other end, capacitor The other end and capacitor The other end is designated as port 1 to port 4 respectively;

[0112] And capacitor All are used as grounding capacitors in the quadrupole moment sensing topology circuit. One end is connected to the data signal input terminal of the impedance analyzer as the output node of the quadrupole moment sensing topology circuit.

[0113] Referring to Figure 4, module 2 includes an inductor. to and capacitors to ,in,

[0114] inductance One end is connected to the capacitor one end and inductor One end is connected simultaneously, inductor The other end is connected to the inductor One end of the inductor One end of the capacitor one end and inductor One end is simultaneously connected to the power ground;

[0115] capacitance The other end is connected to the inductor The other end, capacitor one end and capacitor One end is connected simultaneously;

[0116] inductance The other end is connected to the capacitor One end of the inductor One end of the inductor The other end and capacitor The other end is connected simultaneously;

[0117] capacitance The other end is connected to the capacitor The other end, inductor The other end, capacitor one end and capacitor One end is connected simultaneously;

[0118] inductance One end of the inductor The other end, inductor The other end, capacitor The other end, capacitor The other end and capacitor The other end is designated as port 5 to port 10 respectively;

[0119] Referring to Figure 5, module 3 includes an inductor. to Among them, inductance One end of the inductor one end and inductor The other end is connected to the power ground, and the inductor One end and the other end are designated as port 11 and port 12, respectively.

[0120] Referring to Figure 6, module 4 includes an inductor. to and capacitors to ;in,

[0121] inductance One end is connected to the capacitor one end and capacitor One end of the capacitor is connected simultaneously. The other end is connected to the inductor One end of the capacitor one end and inductor One end is also connected to the power ground;

[0122] capacitance The other end is connected to the capacitor One end of the capacitor one end and inductor The other end is connected simultaneously;

[0123] inductance The other end is connected to the capacitor One end of the capacitor The other end and the inductor One end of the capacitor is connected simultaneously. The other end is connected to the capacitor The other end, inductor The other end and capacitor one end and capacitor One end is connected simultaneously;

[0124] inductance One end of the capacitor One end of the inductor The other end, capacitor The other end, capacitor The other end and capacitor The other end is designated as port 13 to port 18 respectively;

[0125] Referring to Figure 7, module 5 includes an inductor. to and capacitors to ;in,

[0126] inductance One end is connected to the capacitor one end and capacitor One end of the capacitor is connected simultaneously. The other end is connected to the inductor One end of the capacitor one end and capacitor One end is connected simultaneously, inductor The other end is connected to the inductor One end of the capacitor one end and inductor One end is simultaneously connected to the power ground;

[0127] inductance The other end is connected to the inductor The other end, capacitor The other end, capacitor one end and inductor One end of the capacitor is connected simultaneously. The other end is connected to the capacitor The other end, inductor The other end, capacitor one end and capacitor One end is connected simultaneously;

[0128] inductance One end of the inductor The other end, inductor The other end, capacitor The other end, capacitor One end of the capacitor The other end and capacitor The other end is designated as ports 19 to 25 respectively;

[0129] Referring to Figure 8, module 6 includes an inductor. to and capacitors to ;in,

[0130] inductance One end is connected to the capacitor One end is connected to the inductor. The other end is connected to the inductor one end and capacitor One end of the capacitor is connected simultaneously. The other end is connected to the capacitor The other end is also connected to the power ground;

[0131] inductance One end of the inductor The other end and the inductor The other end is designated as ports 26 to 28 respectively;

[0132] Referring to Figure 9, module 7 includes a capacitor. to Among them, capacitors One end of the capacitor is connected to the power supply ground. The other end is connected to the capacitor One end is connected and used as port 29, capacitor The other end is designated as port 30;

[0133] Referring to Figure 10, module 8 includes an inductor. to and capacitors to ;in,

[0134] capacitance One end is designated as port 31;

[0135] capacitance The other end is connected to the capacitor one end and inductor One end is connected simultaneously and used as port 32;

[0136] capacitance The other end is connected to the inductor One end is connected and used as port 33;

[0137] inductance The other end and the inductor The other end is also connected to the power ground;

[0138] Referring to Figure 11, module 9 includes an inductor. to and capacitors to ;in,

[0139] capacitance One end is connected to the capacitor One end is connected and used as port 34; capacitor The other end is connected to the capacitor One end is connected to the capacitor. The other end is connected to the inductor The other end and the inductor One end is connected simultaneously, inductor The other end is connected to the power ground;

[0140] capacitance The other end is connected to the inductor One end is connected and used as port 35;

[0141] Referring to Figures 2, 13, and 14, the four modules 2 are connected in series. In any two adjacent modules 2, ports 9 and 10 of the current module 2 are connected to ports 5 and 6 of the next module 2, respectively. The four modules 2 are defined as modules 1 to 4, and ports 5 and 6 of the first module 2 are connected to ports 4 and 3 of module 1, respectively. Ports 9 and 10 of the fourth module 2 are connected to ports 11 and 12 of module 3, respectively.

[0142] Referring to Figures 2, 13, and 15, the four modules 4 are connected in series. In any two adjacent modules 4, ports 15 and 16 of the current module 4 are connected to ports 13 and 14 of the next module 4, respectively. The four modules 4 are defined as the first to the fourth modules 4, and ports 13 and 14 of the first module 4 are connected to ports 1 and 2 of module 1, respectively. Ports 15 and 16 of the fourth module 4 are connected to ports 29 and 30 of module 7, respectively.

[0143] Referring to Figures 2, 14, and 16, the four modules 6 are connected in series. In any two adjacent modules 6, port 28 of the current module 6 is connected to port 26 of the next module 6. The four modules 6 are defined as modules 1 to 4 respectively, and port 26 of module 1 is connected to port 12 of module 3, and port 28 of module 4 is connected to port 35 of module 9.

[0144] Referring to Figures 2, 15, and 16, the four 8-modules are connected in series. In any two adjacent 8-modules, port 34 of the current 8-module is connected to port 31 of the next 8-module. The four 8-modules are defined as the 1st to the 4th 8-modules, and port 31 of the 1st 8-module is connected to port 30 of the 7th 8-module, and port 33 of the 4th 8-module is connected to port 34 of the 9th 8-module.

[0145] Referring to Figures 2, 13 to 16, 16 modules No. 5 form a 4×4 array. The four modules No. 5 in each row of the array are connected in series. In any two adjacent modules No. 5, ports 24 and 25 of the current module No. 5 are connected to ports 19 and 20 of the next module No. 5, respectively. The four modules No. 5 in each row are defined as modules No. 1 to No. 4.

[0146] Ports 19 and 23 of the first to fourth modules 5 in the first row are connected to ports 7 and 8 of the first to fourth modules 5, respectively.

[0147] Ports 19 to 21 of the first 5th module in rows 1 to 4 are connected to ports 17, 18 and 16 of the first to fourth 4th modules, respectively.

[0148] Ports 24 and 25 of the fourth module 5 in rows 1 to 4 are connected to ports 26 and 27 of the fourth module 6 in rows 1 to 4, respectively.

[0149] Ports 21 and 22 of the first to fourth 5th modules in the fourth row are connected to ports 31 and 33 of the first to fourth 8th modules, respectively.

[0150] In this embodiment, the quadrupole moment sensing topology circuit design utilizes the theory of higher-order topological insulators to construct a circuit system with symmetry-protected angular states, which is the basis for achieving highly robust sensing.

[0151] Angular frequency shift detection mechanism: The change in dielectric constant caused by the analyte (ethanol) is converted into the characteristic frequency shift of the topological boundary state for reading, and the sensitivity is much higher than that of traditional capacitive sensors.

[0152] Active compensation technology for negative resistance units: By introducing negative resistance, the influence of the inherent parasitic resistance of the inductor is effectively offset, significantly improving the system quality factor, thereby enhancing signal resolution and detection accuracy.

[0153] Selective sensitivity and global robustness: The quadrupole moment sensing topology design enables only disturbances to the sensitive unit to be effectively detected, while it has strong immunity to disturbances in other parts of the circuit (such as component aging and environmental fluctuations), which is a direct manifestation of topology protection.

[0154] In practical applications, capacitors , , , , , and The capacitance values ​​are all ;

[0155] capacitance , , , , and The capacitance values ​​are all ,and Here is the topology strength coefficient, and .

[0156] capacitance The capacitance value is ;

[0157] capacitance All capacitance values ​​are ,and It is the standard capacitance coefficient, and inductance , , , , and The sensitivity values ​​are all ;

[0158] inductance , , , , , , The sensitivity values ​​are all ,and Topological strength coefficient; capacitance , , , and The sensitivity values ​​are all ;

[0159] inductance Sensitivity value ;

[0160] inductance Sensitivity value ;

[0161] inductance Sensitivity value ;

[0162] The way to define capacitance and inductance can preserve the topological locality.

[0163] Referring to Figure 12, the negative resistance unit includes a resistor. to ,inductance and operational amplifier ;

[0164] operational amplifier non-inverting input terminal and resistor After one end is connected, it serves as one end of the negative resistance unit;

[0165] operational amplifier The inverting input terminal and the resistor one end and resistor One end is connected at the same time, resistor The other end is connected to the inductor One end is connected to the inductor. The other end serves as the other end of the negative resistance unit;

[0166] resistance The other end is connected to the operational amplifier Output terminal and resistor The other end is connected simultaneously.

[0167] This preferred embodiment provides a specific structure of the negative resistance unit, which plays a key role in the topology circuit. It can actively cancel the inherent positive resistance loss in the circuit, thereby significantly improving the quality factor (Q value) of the resonant circuit, making the resonance peaks of characteristic modes such as topological angle states exceptionally sharp and significant in the spectrum.

[0168] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. An ethanol concentration detection system, characterized in that, The system includes an impedance analyzer, interdigitated capacitors, a quadrupole moment sensing topology circuit, and a processing unit. The interdigitated capacitors sense the concentration of ethanol to be measured. The ethanol concentration causes a change in the capacitance of the interdigitated capacitors, which in turn causes a change in the resistance of the grounding capacitor in the quadrupole moment sensing topology circuit connected in parallel with the interdigitated capacitors. This causes the output node of the quadrupole moment sensing topology circuit to output a changing current, which is sent to the impedance analyzer. The impedance analyzer generates a curve of the output node's impedance to ground versus frequency based on the received changing current. The processing unit extracts the frequency at the peak of the impedance to ground from the curve and calculates the difference between the peak frequency and a standard frequency. Frequency offset Then, by combining the preset linear relationship between the frequency offset and the ethanol concentration, the current frequency offset is obtained. The corresponding ethanol concentration is used as the concentration of the ethanol to be tested.

2. The ethanol concentration detection system according to claim 1, characterized in that, Interdigitated capacitors were placed as sensing elements in a petri dish containing the ethanol to be tested.

3. The ethanol concentration detection system according to claim 1, characterized in that, The four-pole moment sensing topology circuit is divided into 36 modules, which form a 6×6 matrix. The 36 modules are designated as: one module 1, four modules 2, one module 3, four modules 4, sixteen modules 5, four modules 6, one module 7, four modules 8, and one module 9. Module 1 includes an inductor. to ,capacitance to and two negative resistance units; wherein, the capacitor One end is connected to one end of the two negative resistance units, and the capacitor. one end and One end of the capacitor and one end of the interdigitated capacitor are connected simultaneously, and the capacitor... The other end is connected to the inductor One end of the capacitor one end and capacitor One end of the capacitor is connected simultaneously, and the other end of the interdigitated capacitor is connected to the other end of the first negative resistance unit and the capacitor. The other end, capacitor The other end, inductor The other end is also connected to the power supply ground; the other end of the first negative resistor unit is connected to the inductor. One end of the capacitor One end of the inductor one end and capacitor One end is connected simultaneously, inductor The other end is connected to the capacitor The other end and the inductor One end of the capacitor is connected to the power supply ground; The other end is connected to the capacitor The other end, capacitor one end and capacitor One end is connected simultaneously; inductor The other end, capacitor The other end, capacitor The other end and capacitor The other end serves as port 1 to port 4 respectively; and the capacitor All are used as grounding capacitors in the quadrupole moment sensing topology circuit. One end is connected as the output node of the quadrupole moment sensor topology circuit to the data signal input terminal of the impedance analyzer; module 2 includes an inductor. to and capacitors to Among them, inductance One end is connected to the capacitor one end and inductor One end is connected simultaneously, inductor The other end is connected to the inductor One end of the inductor One end of the capacitor one end and inductor One end of the capacitor is connected to the power supply ground; The other end is connected to the inductor The other end, capacitor one end and capacitor One end is connected simultaneously; inductor The other end is connected to the capacitor One end of the inductor One end of the inductor The other end and capacitor The other end is also connected; capacitor The other end is connected to the capacitor The other end, inductor The other end, capacitor one end and capacitor One end is connected simultaneously; inductor One end of the inductor The other end, inductor The other end, capacitor The other end, capacitor The other end and capacitor The other end serves as ports 5 to 10 respectively; module 3 includes an inductor. to Among them, inductance One end of the inductor one end and inductor The other end is connected to the power ground, and the inductor One end and the other end are designated as port 11 and port 12, respectively; module 4 includes an inductor. to and capacitors to Among them, inductance One end is connected to the capacitor one end and capacitor One end of the capacitor is connected simultaneously. The other end is connected to the inductor One end of the capacitor one end and inductor One end of the capacitor is connected to the power supply ground; The other end is connected to the capacitor One end of the capacitor one end and inductor The other end is also connected; inductor The other end is connected to the capacitor One end of the capacitor The other end and the inductor One end of the capacitor is connected simultaneously. The other end is connected to the capacitor The other end, inductor The other end and capacitor one end and capacitor One end is connected simultaneously; inductor One end of the capacitor One end of the inductor The other end, capacitor The other end, capacitor The other end and capacitor The other end serves as ports 13 to 18 respectively; module 5 includes an inductor. to and capacitors to Among them, inductance One end is connected to the capacitor one end and capacitor One end of the capacitor is connected simultaneously. The other end is connected to the inductor One end of the capacitor one end and capacitor One end is connected simultaneously, inductor The other end is connected to the inductor One end of the capacitor one end and inductor One end of the inductor is connected to the power supply ground; The other end is connected to the inductor The other end, capacitor The other end, capacitor one end and inductor One end of the capacitor is connected simultaneously. The other end is connected to the capacitor The other end, inductor The other end, capacitor one end and capacitor One end is connected simultaneously; inductor One end of the inductor The other end, inductor The other end, capacitor The other end, capacitor One end of the capacitor The other end and capacitor The other end serves as ports 19 to 25 respectively; module 6 includes an inductor. to and capacitors to Among them, inductance One end is connected to the capacitor One end is connected to the inductor. The other end is connected to the inductor one end and capacitor One end of the capacitor is connected simultaneously. The other end is connected to the capacitor The other end is also connected to the power supply ground; inductor One end of the inductor The other end and the inductor The other ends are designated as ports 26 to 28; module 7 includes capacitors. to Among them, capacitors One end of the capacitor is connected to the power supply ground. The other end is connected to the capacitor One end is connected and used as port 29, capacitor The other end serves as port 30; module 8 includes an inductor. to and capacitors to Among them, capacitors One end is designated as port 31; capacitor The other end is connected to the capacitor one end and inductor One end is connected simultaneously to serve as port 32; capacitor The other end is connected to the inductor One end is connected and used as port 33; inductor The other end and the inductor The other end is also connected to the power ground; module 9 includes an inductor. to and capacitors to Among them, capacitors One end is connected to the capacitor One end is connected and used as port 34; capacitor The other end is connected to the capacitor One end is connected to the capacitor. The other end is connected to the inductor The other end and the inductor One end is connected simultaneously, inductor The other end is connected to the power supply ground; capacitor The other end is connected to the inductor One end is connected and designated as port 35; four modules 2 are connected in series, with ports 9 and 10 of the current module 2 connected to ports 5 and 6 of the next module 2, respectively; the four modules 2 are defined as modules 1 to 4, with ports 5 and 6 of the first module 2 connected to ports 4 and 3 of the first module 2, and ports 9 and 10 of the fourth module 2 connected to ports 11 and 12 of the third module 3, respectively; four modules 4 are connected in series, with ports 15 and 16 of the current module 4 connected to ports 11 and 12 of the next module 4, respectively. Modules 3 and 14 are connected; the four modules 4 are defined as modules 1 to 4 respectively, with ports 13 and 14 of the first module 4 connected to ports 1 and 2 of module 1 respectively, and ports 15 and 16 of the fourth module 4 connected to ports 29 and 30 of module 7 respectively; the four modules 6 are connected in series, with port 28 of the current module 6 connected to port 26 of the next module 6 in any two adjacent modules; the four modules 6 are defined as modules 1 to 4 respectively, with port 26 of the first module 6 connected to port 12 of module 3, and port 28 of the fourth module 6 connected to port 9 of module 9. Port 35 is connected; four 8-modules are connected in series, with port 34 of the current 8-module connected to port 31 of the next 8-module in any two adjacent 8-modules; the four 8-modules are defined as the 1st to the 4th 8-modules, with port 31 of the 1st 8-module connected to port 30 of the 7th Module, and port 33 of the 4th 8-module connected to port 34 of the 9th Module; 16 5-modules form a 4×4 array, with four 5-modules in each row connected in series, and ports 24 and 25 of the current 5-module connected to ports 19 and 20 of the next 5-module, respectively. The four 5 modules in the row are defined as the first to fourth 5 modules respectively; ports 19 and 23 of the first to fourth 5 modules in the first row are connected to ports 7 and 8 of the first to fourth 5 modules respectively; ports 19 to 21 of the first 5 module in the first to fourth rows are connected to ports 17, 18 and 16 of the first to fourth 4 modules respectively; ports 24 and 25 of the fourth 5 module in the first to fourth rows are connected to ports 26 and 27 of the first to fourth 6 modules respectively; ports 21 and 22 of the first to fourth 5 modules in the fourth row are connected to ports 31 and 33 of the first to fourth 8 modules respectively.

4. The ethanol concentration detection system according to claim 3, characterized in that, The negative resistance unit includes a resistor. to ,inductance and operational amplifier Operational amplifier non-inverting input terminal and resistor After one end is connected, it serves as one end of the negative resistance unit; operational amplifier The inverting input terminal and the resistor one end and resistor One end is connected at the same time, resistor The other end is connected to the inductor One end is connected to the inductor. The other end serves as the other end of the negative resistance unit; resistor The other end is connected to the operational amplifier Output terminal and resistor The other end is connected simultaneously.

5. The ethanol concentration detection system according to claim 3, characterized in that, capacitance 、 、 、 、 、 and The capacitance values ​​are all ;capacitance 、 、 、 、 and The capacitance values ​​are all ,and Topological strength coefficient; capacitance The capacitance value is ;capacitance All capacitance values ​​are ,and This is the standard capacitance coefficient.

6. The ethanol concentration detection system according to claim 3, characterized in that, inductance 、 、 、 、 and The sensitivity values ​​are all ;inductance 、 、 、 、 、 、 The sensitivity values ​​are all ,and Topological strength coefficient; capacitance 、 、 、 and The sensitivity values ​​are all ;inductance Sensitivity value ,inductance Sensitivity value ,inductance Sensitivity value 。 7. The ethanol concentration detection system according to claim 5 or 6, characterized in that, 。 8. The ethanol concentration detection system according to claim 5 or 6, characterized in that, 。

Images