High-precision multi-trace mass-position synchronization sensing device and method based on multimodal approaches

Abstract

This invention belongs to the field of multi-substance identification and detection technology, and particularly relates to a high-precision multi-trace mass-position synchronous sensing device and method based on multimodality; it includes a cantilever beam of variable length and an adjustable support, wherein the end of the cantilever beam is selectively connected to the adjustable support. The cantilever beam includes an upper insulating layer, a base beam, and a lower insulating layer arranged and connected from top to bottom. Piezoelectric driving electrodes and piezoelectric output electrodes are respectively provided on both sides above the upper insulating layer, and uniformly distributed adsorption units are provided on the upper insulating layer between the piezoelectric driving electrodes and the piezoelectric output electrodes. This invention establishes a mass-position synchronous sensing theory, realizes the synchronous detection of mass and position of multiple trace substances, and improves the accuracy of the detection device.

Description

Technical Field

[0001] This invention belongs to the field of multi-substance identification and detection technology, and in particular relates to a high-precision multi-trace mass-position synchronous sensing device and method based on multimodality. Background Technology

[0002] With the advancement of technology and the continuous development of human production and life, the demand for substance detection is also rapidly increasing. Applications such as virus and pollen detection in public spaces, pollutant detection in outdoor air, dust detection in factories, and component determination of biological macromolecules are of great practical significance for safeguarding human health and promoting the rapid development of human production and life. Currently available methods for substance detection mainly include spectroscopic analysis, gas chromatography, liquid chromatography, and inductively coupled plasma mass spectrometry. However, these methods all have many drawbacks, such as requiring large detection equipment, complex detection procedures, and long response times.

[0003] Resonant sensors, which convert the measured quantity into a vibration frequency signal, are characterized by their miniaturization and ease of integration, making them widely applicable in various daily life and production scenarios. Resonant sensors also offer advantages such as high sensitivity, fast response speed, and good stability, demonstrating significant potential for material detection. Existing resonant sensors have achieved significant breakthroughs in sensitivity and resolution for single-material detection through mechanisms such as internal resonance, modal localization, and synchronous resonance. However, challenges remain in multi-material detection, especially in the synchronous detection of mass and position of multiple materials. Compared to other resonant sensors, cantilever beam sensors offer advantages such as simple structure, high reliability, and low cost. Furthermore, due to their structural characteristics, they are more suitable for the synchronous sensing of position and mass of multiple materials. However, current sensing mechanisms and methods applied to multi-material identification and detection still suffer from limitations in sensitivity, narrow detection range, and the inability to simultaneously perform high-precision mass-position detection. Summary of the Invention

[0004] To overcome the above problems, this invention provides a high-precision multi-trace mass-position synchronous sensing device and method based on multimodality, establishes a mass-position synchronous sensing theory, realizes the synchronous detection of mass and position of multiple trace substances, and improves the accuracy of the detection device.

[0005] A multimodal high-precision multi-trace mass-position synchronous sensing device includes a variable-length cantilever beam 1 and an adjustable support 2. The end of the cantilever beam 1 is connected to the adjustable support 2 at a selectable length. The cantilever beam 1 includes an upper insulating layer 106, a base beam 107, and a lower insulating layer 108 arranged and connected from top to bottom. Piezoelectric driving electrodes 104 and piezoelectric output electrodes 105 are respectively provided on both sides above the upper insulating layer 106. The upper insulating layer 106 between the piezoelectric driving electrodes 104 and the piezoelectric output electrodes 105 is provided with evenly distributed adsorption units 103.

[0006] The cantilever beam 1 is divided into two parts, left and right. The left side is the length adjustment area 101 and the right side is the mass-position sensing area 102. The length adjustment area 101 is clamped in the groove at the top of the adjustable support 2 and has scale lines. The upper insulating layer 106 of the mass-position sensing area 102 has piezoelectric drive electrodes 104 and piezoelectric output electrodes 105 on both sides.

[0007] The piezoelectric driving electrode 104 includes an upper piezoelectric electrode 10401, a piezoelectric thin film 10402, and a lower piezoelectric electrode 10403, which are arranged and connected sequentially from top to bottom.

[0008] The piezoelectric output electrode 105 includes an upper piezoelectric electrode 10501, a piezoelectric film 10502, and a lower piezoelectric electrode 10503, which are arranged and connected sequentially from top to bottom.

[0009] The cantilever beam 1 can be transformed into a double-ended fixed beam with adjustable length.

[0010] The adsorption unit 103 is an adsorption membrane.

[0011] A high-precision mass-position synchronization method based on multimodal and multi-trace parameters includes the following steps:

[0012] Step 1: For the cantilever beam 1 that has not adsorbed the analyte, at its n lengths L... n The two modal frequencies are calibrated, where the length of cantilever beam 1 is the length of the suspended portion of cantilever beam 1:

[0013] The first two natural frequencies ω of cantilever beam 1 with n different lengths are respectively n1 ω n2 Nearby, a sweep frequency signal is input through the piezoelectric drive electrode 104 at a frequency of 0.8 ω. n1 up to 1.2ω n1 The modal frequency range and 0.8ω n2 up to 1.2ω n2 The modal frequency range was subjected to two cyclic forward frequency sweep excitations, with an excitation acceleration of a. dcos(Ωt); The cantilever beam 1 outputs a voltage signal containing vibration information through the piezoelectric output electrode 105. The amplitude-frequency characteristic curves of the first two modes of the cantilever beam 1 with respect to the excitation modal frequency are plotted with the intensity of the piezoelectric signal, i.e., the voltage value, as the vertical axis and the excitation frequency as the horizontal axis. The horizontal axis corresponding to the maximum intensity of the piezoelectric signal is the first two natural frequencies of the cantilever beam 1.

[0014] Step 2: Place the synchronous sensing device in the test environment and adsorb P test substances onto any adsorption unit 103 on the cantilever beam 1. Each adsorption unit 103 can adsorb at most one test substance, and the test substance can only be placed on the mass-position sensing area 102.

[0015] Step 3: Change the length of cantilever beam 1, specifically when the length of cantilever beam 1 is its nth length L. n A positive sweep frequency signal is cyclically input to the cantilever beam 1 through the piezoelectric drive electrode 104, and a voltage signal containing vibration information is output through the piezoelectric output electrode 105. The amplitude-frequency characteristic curves of the cantilever beam 1 at different lengths, varying with the mass and position of the measured material, are plotted with the intensity of the piezoelectric signal as the ordinate and the excitation frequency as the abscissa. Fourier transform is used to calculate the amplitude-frequency characteristic curves of the cantilever beam 1 at lengths L. n The first two modal frequencies ω' after adsorption of the substance n1 and ω' n2 ;

[0016] Step four, add ω' n1 and ω' n2 Substitute into the following formula to calculate the mass and position of the substance being measured:

[0017] Ud=R ω

[0018] Where U is a matrix determined by the positions of each substance being measured:

[0019]

[0020] Among them U i,n (z k,n )=L1 / L n ·H(z k,1 ), i = 1, 2, are the modal orders of cantilever beam 1, z k,n When the cantilever beam 1 is of the nth length L n The relative position of the k-th measured substance on it, k = 1, 2, 3... P, H(z) k,1 The normalized modal function value of the relative position of the k-th measured material along the actual length of the cantilever beam 1 is calculated by the following formula:

[0021] H n (z)=cos≤n z - cosh ≤ n z + ξ n (sin κ n z - sinh κ n z)

[0022] where z is the independent variable, z = z 1，1 , z 2，1 , z 3,1 …… z k,1 , refers to the relative position of the k-th substance to be measured on the actual length of the cantilever beam 1, 0 < z < 1, the range is 0 to 1; H n (z) is the corresponding function value, H(z k，1 ) is H n (z) when n = 1; ≤ n z is the solution of the equation cos κ nz cosh κ nz = -1, after normalizing the modal vibration shape , the coefficient ζ n = -0.7342, -1.0183, -0.9999, -1.0000, R ω is a vector composed of the first two modal frequencies before and after the mass perturbation applied by the cantilever beam 1:

[0023]

[0024] d is a vector composed of the mass ratios of the measured substances to the cantilever beam 1:

[0025]

[0026] where Δm k is the mass of the k-th measured substance, m0 is the actual mass of the cantilever beam 1, P is the number of measured substances, and T represents the transpose;

[0027] Step five, z k,1 is the relative position of the k-th measured substance on the actual length of the cantilever beam 1, and it may be any position on the mass-position sensing area 102 of the cantilever beam 1, where the length of the mass-position sensing area 102 is L s , select an appropriate iteration accuracy ΔL according to the relative size of the measured substance and the mass-position sensing area 102, and convert the continuous distribution probability of the relative position z k,1 of the measured substance into a discrete distribution probability. Through iteration, all possible (L s / ΔL) P cases of the measured substances are substituted into Ud = R ω , that is, through iteration, all possible cases of z k,1 are substituted into Ud = R ωFind the least squares solution for each case using the least squares method. and residual δ, where the residual takes the minimum value δ. min The corresponding z k,1 That is, the relative position of the k-th measured material on the actual length of cantilever beam 1. Then, the k-th measured material on cantilever beam 1 is of the nth length L. n The position of time on it δ min The corresponding least squares solution That is, the vector d is composed of the mass ratio of the k-th measured material to the cantilever beam 1. Therefore, according to Ud = R in step four... ω It is possible to determine the mass of the kth substance being tested.

[0028] The beneficial effects of this invention are:

[0029] 1. The multi-mode vibration of the cantilever beam was applied to the detection of multiple materials, enabling the simultaneous detection of the position and mass of multiple materials.

[0030] 2. By utilizing the vibration modes of a variable-length cantilever beam at different lengths, the mass-position synchronization of multiple materials can be achieved using only the first two easily excitable low-order modes of the variable-length cantilever beam. The structural design is ingenious and the idea is novel.

[0031] 3. It has the advantages of low power consumption, fast response, simple structure, low cost, and single input and single output. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments of the present invention will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the content of the embodiments of the present invention and these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present invention;

[0034] Figure 2 This is a top view of Embodiment 1 of the present invention;

[0035] Figure 3 This is a front view of Embodiment 1 of the present invention;

[0036] Figure 4 This is a schematic diagram of the structure in Embodiment 2 of the present invention showing the change in the ratio of the length adjustment region to the mass-position sensing region;

[0037] Figure 5 This is a schematic diagram of the structure of Embodiment 3 of the present invention when the number of adsorption units is 6;

[0038] Figure 6 This is a schematic diagram of the structure of the adjustable length cantilever beam transformed into an adjustable length double-end fixed beam in Embodiment 4 of the present invention;

[0039] Figure 7 This is a schematic diagram of the structure of Embodiment 5 of the present invention;

[0040] Figure 8 This is a schematic diagram of the structure of Embodiment 6 of the present invention;

[0041] Figure 9 This is a schematic diagram of the structure of Embodiment 7 of the present invention;

[0042] Figure 10 This is a schematic diagram of the structure of Embodiment 8 of the present invention;

[0043] Figure 11 This is a schematic diagram of the structure of Embodiment 9 of the present invention;

[0044] Figure 12 This is a schematic diagram of the structure of Embodiment 10 of the present invention. Detailed Implementation

[0045] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0046] Example 1

[0047] like Figure 1-3 As shown, a multimodal high-precision multi-trace mass-position synchronous sensing device includes a variable-length cantilever beam 1 and an adjustable support 2. The end of the cantilever beam 1 is selectively connected to the adjustable support 2. The cantilever beam 1 includes an upper insulating layer 106, a base beam 107, and a lower insulating layer 108 arranged and connected from top to bottom. The cantilever beam 1 is divided into left and right parts. The left side is a length adjustment area 101, and the right side is a mass-position sensing area 102. The length adjustment area 101 is clamped in a groove at the top of the adjustable support 2, and the length adjustment area 101 is provided with scale lines. Piezoelectric driving electrodes 104 and piezoelectric output electrodes 105 are respectively provided on both sides above the upper insulating layer 106 of the mass-position sensing area 102. The upper insulating layer 106 between the piezoelectric driving electrodes 104 and the piezoelectric output electrodes 105 is provided with evenly distributed adsorption units 103 for adsorbing the analyte.

[0048] The length of the cantilever beam 1, i.e. the part that is not in contact with the adjustable support 2, is adjusted by clamping the length adjustment area 101 at different positions in the top groove of the adjustable support 2. In detail, the length adjustment area 101 is used to clamp the cantilever beam 1. The length is adjusted by changing the clamping area of ​​the cantilever beam 1 by moving the adjustable support 2 along the length direction of the cantilever beam 1. The clamping area is not greater than the area of ​​the length adjustment area 101.

[0049] The piezoelectric driving electrode 104 includes an upper piezoelectric electrode 10401, a piezoelectric thin film 10402, and a lower piezoelectric electrode 10403, which are arranged and connected sequentially from top to bottom.

[0050] The piezoelectric output electrode 105 includes an upper piezoelectric electrode 10501, a piezoelectric film 10502, and a lower piezoelectric electrode 10503, which are arranged and connected sequentially from top to bottom.

[0051] The cantilever beam 1 can be transformed into a double-ended fixed beam with adjustable length.

[0052] The adsorption unit 103 is an adsorption membrane. The substance to be tested can be adsorbed onto it.

[0053] The position and number of the adsorption units 103 can vary with the spacing between the adsorption units 103; the ratio between the length adjustment region 101 and the mass-position sensing region 102 can vary.

[0054] The spacing and number of scale lines on the length adjustment area 101 can be varied.

[0055] A high-precision mass-position synchronization method based on multimodal and multi-trace parameters includes the following steps:

[0056] Step 1: For the cantilever beam 1 that has not adsorbed the analyte, at its n lengths L... n The two modal frequencies are calibrated, where the length of the cantilever beam 1 is the length of the suspended part of the cantilever beam 1, that is, the length of the part of the cantilever beam 1 that is not on the adjustable support 2.

[0057] The first two natural frequencies ω of cantilever beam 1 with n different lengths are respectively n1 ω n2 Nearby, a sweep frequency signal is input through the piezoelectric drive electrode 104 at a frequency of 0.8 ω. n1 up to 1.2ω n1 The modal frequency range and 0.8ω n2 up to 1.2ω n2 The modal frequency range was subjected to two cyclic forward frequency sweep excitations, with an excitation acceleration of a. d cos(Ωt);

[0058] The cantilever beam 1 outputs a voltage signal containing vibration information through the piezoelectric output electrode 105. The intensity of this piezoelectric signal, i.e., the voltage value, is plotted on the ordinate, and the excitation frequency (i.e., 0.8 ω) is plotted on the other side. n1 up to 1.2ω n1 The modal frequency range and 0.8ω n2 up to 1.2ω n2 The amplitude-frequency characteristic curves of the first two modes of the cantilever beam 1 with respect to the modal frequencies of the excitation are plotted with the range of modal frequencies of the cantilever beam 1 as the abscissa. The abscissa corresponding to the maximum value of the piezoelectric signal intensity, i.e. the voltage value, is the first two natural frequencies of the cantilever beam 1.

[0059] Step 2: Place the synchronous sensing device in the test environment and adsorb P test substances onto any adsorption unit 103 on the cantilever beam 1. Each adsorption unit 103 can adsorb at most one test substance, and the test substance can only be placed on the mass-position sensing area 102 that can vibrate continuously and will not be clamped.

[0060] Step 3: Change the length of cantilever beam 1, specifically when the length of cantilever beam 1 is its nth length L. n A positive sweep frequency signal is cyclically input to the cantilever beam 1 through the piezoelectric drive electrode 104, and a voltage signal containing vibration information is output through the piezoelectric output electrode 105. The amplitude-frequency characteristic curves of the cantilever beam 1 at different lengths as a function of the mass and position of the measured material are plotted with the intensity of the piezoelectric signal (voltage value) as the ordinate and the excitation frequency as the abscissa. The Fourier transform is used to calculate the amplitude-frequency characteristic curves of the cantilever beam 1 at lengths L. n The first two modal frequencies ω' after adsorption of the substance n1 and ω' n2 ;

[0061] Step four: Since the mass of the adsorbed material is much smaller than the mass of cantilever beam 1, the mode shapes of cantilever beam 1 remain almost unchanged. Based on the principle of energy conservation, the following equation can be obtained:

[0062]

[0063] Among them, E strain Let E be the average strain energy of cantilever beam 1. kin Let be the average kinetic energy of cantilever beam 1. The sum of the average kinetic energies of all the substances measured on each adsorption unit 103; the strain energy of the cantilever beam 1 can be calculated by the following formula:

[0064]

[0065] Where m0 is the actual mass of cantilever beam 1, a i Let ω be the amplitude of the i-th mode of the cantilever beam 1. ni For cantilever beam 1 with a length of L nThe i-th modal frequency when the analyte is not adsorbed, and the average kinetic energy E of cantilever beam 1. kin Calculate using the following formula:

[0066]

[0067] The sum of the average kinetic energies of the various substances adsorbed on cantilever beam 1 is calculated using the following formula:

[0068]

[0069] Where i is the modal order, P is the number of substances being measured, and Δm k Let z be the mass of the kth analyte that has been adsorbed. k,n When the length of cantilever beam 1 is L n The position of the k-th analyte on it; H i,n (z k,n ) represents the normalized mode shape function value at the location of the kth measured substance; the i-th modal frequency of the cantilever beam 1 before and after adsorption of the substance. and The following relationship must be satisfied:

[0070]

[0071] Taking the example of changing the length of cantilever beam 1 once and measuring the mass and position of three substances, the following relationship can be obtained:

[0072] Ud=R ω

[0073] ω' n1 and ω' n2 Substituting into the above equation, Ud = R ω Where U is a matrix determined by the positions of each substance being measured:

[0074]

[0075] Among them U i,n (z k,n )=L1 / L n ·H(z k,1 ), i = 1, 2, are the modal orders of cantilever beam 1. This method uses the first two modes of the cantilever beam, z k,n When the cantilever beam 1 is of the nth length L n The relative position of the k-th measured substance on it, k = 1, 2, 3... P, H(z) k,1 The normalized modal function value of the relative position of the k-th measured material along the actual length of cantilever beam 1 at n=1 is calculated by the following formula:

[0076] H nψ(z) = cosκ n z - coshκ n z + ξ n (sinκ n z - sinhκ n z)

[0077] where z is the independent variable, z = z 1，1 , z 2，1 , z 3,1 ……z k,1 , refers to the relative position of the k-th substance to be measured on the actual length of the cantilever beam 1, 0 < z < 1. For example, at the midpoint it is 1 / 2, at the end it is 1, at the fixed end of the original length it is 0, at a distance of 1 / 4 from the end it is 3 / 4, ranging from 0 to 1 from the fixed end to the end; H n ψ(z) is the corresponding function value, H(z k，1 ) is H n ψ(z) when n = 1; κ n z is the solution of the equation cos κ nzcosh κ nz = -1. This equation has infinitely many solutions, κ n z = 1.875, 4.964, 7.855, 10.996…, Cosh is the hyperbolic cosine function. After normalizing the modal shape , the coefficient ζ n = -0.7342, -1.0183, -0.9999, -1.0000. That is to say, the value of the coefficient is obtained through the integral equation of the normalized modal shape; R ω is a vector composed of the first two modal frequencies before and after the mass perturbation applied by the cantilever beam 1:

[0078]

[0079] d is a vector composed of the mass ratios of the measured substances to the cantilever beam 1:

[0080]

[0081] where Δm k is the mass of the k-th measured substance, m0 is the initial mass of the cantilever beam 1 when its length is the actual length L1, that is, the actual mass of the cantilever beam 1, P is the number of measured substances, and T represents the transpose;

[0082] Step five, z k,1 is the relative position of the k-th measured substance on the actual length of the cantilever beam 1, which may be any position on the mass-position sensing area 102 of the cantilever beam 1, where the length of the mass-position sensing area 102 is L sBased on the relative dimensions of the measured substance and the mass-position sensing area 102, select an appropriate iteration precision ΔL (e.g., %0.1 of the total length of cantilever beam 1, %0.5 of the total length of cantilever beam 1, %1 of the total length of cantilever beam 1, etc.) to determine the relative position z of the measured substance. k,1 The continuous probability distribution is transformed into a discrete probability distribution, and through iteration, all possible co-occurrences of each tested substance (L) are obtained. s / ΔL) P Substituting this case into Ud=R ω That is, by iterating z k,1 Substitute all possible scenarios into Ud = R ω Find the least squares solution for each case using the least squares method. and residual δ, where the residual takes the minimum value δ. min The corresponding z k,1 That is, the relative position of the k-th measured material on the actual length of cantilever beam 1. Then, the k-th measured material on cantilever beam 1 is of the nth length L. n The position of time on it δ min The corresponding least squares solution That is, the vector d is composed of the mass ratio of the k-th measured material to the cantilever beam 1. Therefore, according to Ud = R in step four... ω It is possible to calculate the mass of the k-th measured substance when the length of the cantilever beam 1 is L1, which is the actual length. Here, L1 is the actual length of the cantilever beam 1 (i.e., the sum of the lengths of the length adjustment area 101 and the mass-position sensing area 102; k=1 is the longest length of the cantilever beam 1, which is the actual length, because even at the longest length, a part must be clamped. As k increases to 2, 3, 4..., the clamped part of the cantilever beam 1 increases, and the suspended part gradually becomes shorter accordingly).

[0083] Because the fixed end of the cantilever beam 1 will move after the test object is placed on it, when the cantilever beam 1 becomes shorter, it is equivalent to cutting off a section of the cantilever beam 1 near the fixed end after placing the test object on it. The new cross-section becomes the new fixed end point. The test object on the cantilever beam 1 has a new relative position z due to the change in the length of the cantilever beam 1. k，n However, since the length that was cut off is known, the relative positions z of these materials each time the cantilever beam 1 changes are... k，n It can be calculated, given z. k，1 Then we can find z k，2 z k，3 Up to z k，n .

[0084] Taking the detection of three substances as an example, theoretically, each substance can exist at any position from the leftmost to the rightmost end of the mass-position sensing area 102 of the cantilever beam 1. In the solution, it is assumed that each substance may exist at a scale position at intervals of 1% of the total adjustable cantilever beam length from the leftmost to the rightmost end of the mass-position sensing area 102. Assuming the length of the mass-position sensing area 102 is 80% of the total adjustable cantilever beam length, the total number of possible cases is 80. 3 If the quantity of the substance being tested is 4, then the total number of possible combinations is 80. 4 The number of species can be represented by the following formula: N = k P N represents all possible quantities, k represents the number of possible distributions of each measured substance on the cantilever beam, and k can take different values ​​depending on the interval highlighted in yellow above. The larger the k, the more precise the distribution. P represents the number of measured substances.

[0085] Example 2

[0086] like Figure 4 As shown, it is the same as in Embodiment 1, except that the ratio of the length adjustment area 101 and the mass-position sensing area 102 on the length-adjustable cantilever beam 1 is different from that in Embodiment 1.

[0087] Example 3

[0088] like Figure 5 As shown, it is the same as in Example 1, except that the number of adsorption units 103 is 6.

[0089] Example 4

[0090] like Figure 6 As shown, similar to Embodiment 1, the difference is that the length-adjustable cantilever beam 1 is replaced by a length-adjustable double-end fixed beam, with one support end fitted on the adjustable support 2 and the other support end fixed on the non-adjustable support 3. Furthermore, four adsorption units 103 are provided on the upper insulating layer 106 between the piezoelectric drive electrode 104 and the piezoelectric output electrode 105, and five adsorption units 103 are provided on the upper insulating layer 106 between the piezoelectric output electrode 105 and the non-adjustable support 3.

[0091] Example 5

[0092] like Figure 7 As shown, the same as in Embodiment 1, except that the length-adjustable cantilever beam 1 is replaced by a length-adjustable double-ended fixed beam, with one support end attached to an adjustable support 2 and the other support end attached to another adjustable support 2. Furthermore, four adsorption units 103 are provided on the upper insulating layer 106 between the piezoelectric drive electrode 104 and the piezoelectric output electrode 105, and five adsorption units 103 are provided on the upper insulating layer 106 between the piezoelectric output electrode 105 and the right-side adjustable support 2.

[0093] Example 6

[0094] like Figure 8 As shown, the cantilever beam 1 is a single piece, including a first base 4 and a first cantilever beam body located at one end of the base and extending outward. There are gaps between the two sides of the end of the first cantilever beam body and the first base 4. Three first piezoelectric sheets 1001 are bonded to the first base 4 in each gap. The length of the adjustable cantilever beam 1 is controlled by the three pairs of first piezoelectric sheets 1001. The adsorption unit 103, the piezoelectric driving electrode 104 and the piezoelectric output electrode 105 are all disposed on the extended first cantilever beam body.

[0095] The second cantilever beam 5 is a single piece, including a second base 6 and a second cantilever beam body located at one end of the base and extending outward. Gaps are provided between the two sides of the end of the second cantilever beam body and the second base 6. Three second piezoelectric sheets 501 are bonded to the second base 6 within each gap. The length of the length-adjustable second cantilever beam 5 is controlled by three pairs of second piezoelectric sheets 501. The second piezoelectric output electrode 502 and the second piezoelectric drive electrode 503 are both disposed on the extended second cantilever beam body.

[0096] The vibration signal of the cantilever beam 1 is input to the piezoelectric drive electrode 104 after passing through an amplifier, a phase-locked circuit, and a voltage limiting circuit from the piezoelectric output electrode 105, generating self-excited oscillation. The vibration signal of the second cantilever beam 5 is input to the second piezoelectric drive electrode 503 after passing through an amplifier, a phase-locked circuit, and a voltage limiting circuit from the second piezoelectric output electrode 502, generating self-excited oscillation. The cantilever beam 1 and the second cantilever beam 5 are coupled to each other through the circuit. The resonant frequency of the second cantilever beam 5 is approximately n times that of the cantilever beam 1 (n is a positive integer).

[0097] After the substance to be tested is adsorbed onto the adsorption unit 103 on the cantilever beam 1, the cantilever beam 1 generates a frequency shift. Due to synchronous resonance, the frequency shift of the second cantilever beam 5 is multiplied. Finally, the mass and position of the substance to be tested are calculated through the resonant frequency of the second cantilever beam 5.

[0098] Example 7

[0099] Same as in Example 6, such as Figure 9 As shown, the difference lies in that the second cantilever beam 5 is a double-ended fixed beam, including a signal detection area 504, a length adjustment area 505, a piezoelectric drive electrode 104, and a piezoelectric output electrode 105. One end of the second cantilever beam 5 is a non-adjustable support 3, and the other end is an adjustable support 2.

[0100] Example 8

[0101] like Figure 10As shown, cantilever beam 1 is a double-ended fixed beam with adjustable length, including a mass-position sensing area 102, a length adjustment area 101, an adsorption unit 103, a piezoelectric driving electrode 104, and a piezoelectric output electrode 105. The second cantilever beam 5, also with adjustable length, is a double-ended fixed beam, including a signal detection area 504, a length adjustment area 505, a second piezoelectric driving electrode 503, and a second piezoelectric output electrode 502. One end of cantilever beam 1 is a non-adjustable support 3, and the other end is an adjustable support 2. One end of the second cantilever beam 5 is an adjustable support 2, and the other end is a non-adjustable support 3. The resonant frequency ratio of cantilever beam 1 and the second cantilever beam 5 is approximately 1:n (n is a positive integer). Mechanical coupling and synchronous resonance occur through coupling part 6. When the analyte is adsorbed onto the adsorption unit 103, the long cantilever beam 1 experiences a frequency shift. Due to synchronous resonance, the frequency shift of the second cantilever beam 5 is multiplied. Finally, the mass and position of the analyte are calculated from the resonant frequency of the second cantilever beam 5.

[0102] Example 9

[0103] like Figure 11 As shown, it is the same as in Example 8, except that there are local recesses 506, local heterogeneity 507, local rectangular protrusions 508, irregularly shaped local protrusions 509, and circular through holes 510 on the double-ended fixed beam.

[0104] Example 10

[0105] like Figure 12 As shown, it is the same as in Example 8, except that the length of the coupling part 6 is different.

[0106] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the scope of protection of the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, any person skilled in the art can make equivalent substitutions or changes based on the technical solution and inventive concept of the present invention within the scope of the technology disclosed in the present invention. These simple modifications are all within the scope of protection of the present invention.

[0107] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0108] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for achieving high-precision mass-position synchronization across multiple modes and trace quantities, characterized in that... Includes the following steps: Step 1, for the cantilever beam (1) that has not adsorbed the analyte, at its n lengths The two modal frequencies are calibrated, where the length of the cantilever beam (1) is the length of the suspended part of the cantilever beam (1); In respectively The first two natural frequencies of cantilever beams of different lengths (1) , Nearby, a sweep frequency signal is input through the piezoelectric drive electrode (104) at a frequency of 0.

8. Up to 1.2 The modal frequency range and 0.8 Up to 1.2 The modal frequency range was subjected to two cyclic forward frequency sweep excitations, with an excitation acceleration of... ; The cantilever beam (1) outputs a piezoelectric signal containing vibration information through the piezoelectric output electrode (105). The amplitude-frequency characteristic curves of the first two modes of the cantilever beam (1) with respect to the excitation modal frequency are plotted with the intensity of the piezoelectric signal, i.e., the voltage value, as the vertical axis and the excitation frequency as the horizontal axis. The horizontal axis corresponding to the maximum value of the piezoelectric signal intensity, i.e., the voltage value, is the first two natural frequencies of the cantilever beam (1). Step two, place the synchronous sensing device in the environment under test, and... The test substance is adsorbed on any adsorption unit (103) on the cantilever beam (1). Each adsorption unit (103) can adsorb at most one test substance, and the test substance can only be placed on the mass-position sensing area (102). Step 3, change the length of the cantilever beam (1), respectively, at lengths of the cantilever beam (1) that are its first... Type of length A positive sweep frequency signal is cyclically input to the cantilever beam (1) through the piezoelectric driving electrode (104), and a piezoelectric signal containing vibration information is output through the piezoelectric output electrode (105). The amplitude-frequency characteristic curves of the cantilever beam (1) at different lengths as a function of the mass and position of the measured material are plotted with the intensity (voltage) of the piezoelectric signal as the vertical axis and the excitation frequency as the horizontal axis. The horizontal axis corresponding to the maximum intensity (voltage) of the piezoelectric signal is used to obtain the amplitude-frequency characteristic curves of the cantilever beam (1) at different lengths as a function of the mass and position of the measured material. The first two modal frequencies after adsorption of substances and ; Step four, and Substitute into the following formula to calculate the mass and position of the substance being measured: in It is a matrix determined by the positions of each substance being measured: in i=1, 2, are the modal orders of the cantilever beam (1). When the cantilever beam (1) is of the nth length Time The relative positions of the tested substances on it, k=1,2,3……P, For the first The standardized modal function values ​​of the relative positions of the tested material along the actual length of the cantilever beam (1) are calculated by the following formula: Where z is the independent variable, z = z 1，1 z 2，1 , z 3,1 ... z k,1 , refers to the relative position of the k-th test material on the actual length of the cantilever beam (1), 0 < z < 1, and the range is 0~1; It is the corresponding function value. When n=1 ; It is an equation The solution, normalized modal vibration mode After =1, the coefficient is obtained. , It is a vector composed of the first two modal frequencies before and after the mass disturbance is applied to the cantilever beam (1): d is a vector composed of the mass ratios of each measured substance to the cantilever beam (1): in For the first The mass of the substance being tested P represents the actual mass of the cantilever beam (1), P is the quantity of the measured material, and T represents transposition. Step 5, For the first The relative position of the measured substance along the actual length of the cantilever beam (1) can be any position on the mass-position sensing area (102) of the cantilever beam (1), where the length of the mass-position sensing area (102) is... The appropriate iteration accuracy is selected based on the relative size of the measured substance and the mass-position sensing area (102). The relative position of the substance being tested The continuous probability distribution is transformed into a discrete probability distribution, and all possible common probabilities of each substance under test are iteratively calculated. Substitute the following cases That is, through iteration Substitute all possible scenarios Find the least squares solution for each case using the least squares method. and residual The residual takes the minimum value. Time corresponding That is, the relative position of the k-th measured material on the actual length of the cantilever beam (1), then the k-th measured material on the cantilever beam (1) is the n-th length L. n The position of time on it , The corresponding least squares solution That is, the vector d is composed of the mass ratio of the k-th measured material to the cantilever beam (1), therefore, according to step four... It is possible to determine the mass of the kth substance being tested.

2. The method for achieving high-precision mass-position synchronization of multiple modes and trace quantities according to claim 1, characterized in that, The device is implemented using a multimodal high-precision multi-trace mass-position synchronous sensing device. The device includes a cantilever beam (1) of variable length and an adjustable support (2). The end of the cantilever beam (1) can be selectively connected to the adjustable support (2). The cantilever beam (1) includes an upper insulating layer (106), a base beam (107), and a lower insulating layer (108) arranged and connected from top to bottom. The upper insulating layer (106) has a piezoelectric driving electrode (104) and a piezoelectric output electrode (105) on its two sides above, and the upper insulating layer (106) between the piezoelectric driving electrode (104) and the piezoelectric output electrode (105) has evenly distributed adsorption units (103).

3. The method for achieving high-precision mass-position synchronization of multiple modes and trace quantities according to claim 1, characterized in that, The cantilever beam (1) is divided into two parts, left and right. The left side is the length adjustment area (101) and the right side is the mass-position sensing area (102). The length adjustment area (101) is clamped in the groove at the top of the adjustable support (2), and the length adjustment area (101) is provided with scale lines. The upper insulating layer (106) of the mass-position sensing area (102) is provided with piezoelectric drive electrode (104) and piezoelectric output electrode (105) on both sides respectively.

4. The method for achieving high-precision mass-position synchronization of multiple modes and trace quantities according to claim 3, characterized in that, The piezoelectric driving electrode (104) includes an upper piezoelectric electrode (10401), a piezoelectric film (10402), and a lower piezoelectric electrode (10403) arranged and connected from top to bottom.

5. The method for achieving high-precision mass-position synchronization of multiple modes and trace quantities according to claim 3, characterized in that, The piezoelectric output electrode (105) includes an upper piezoelectric electrode (10501), a piezoelectric film (10502), and a lower piezoelectric electrode (10503) arranged and connected from top to bottom.

6. The method for achieving high-precision mass-position synchronization of multiple modes and trace quantities according to claim 2, characterized in that, The cantilever beam (1) can be transformed into a double-ended fixed beam with adjustable length.

7. The method for achieving high-precision mass-position synchronization of multiple modes and trace quantities according to claim 2, characterized in that, The adsorption unit (103) is an adsorption membrane.

Images