Single droplet dynamic response detection device and method based on TENG alternating electric field excitation
The single-droplet dynamic response detection device based on alternating electric field excitation of triboelectric nanogenerator solves the problems of large size, complex operation, large sample volume and severe droplet detection electric field attenuation in existing solution ion detection devices. It realizes label-free, small sample volume, rapid and accurate solution composition analysis, which is suitable for portable devices.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- HEBEI UNIVERSITY
- Filing Date
- 2026-04-22
- Publication Date
- 2026-06-12
Smart Images
Figure CN122193306A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of intelligent sensing and microfluidic analysis technology, specifically to a single droplet dynamic response detection device and method based on TENG alternating electric field excitation. Background Technology
[0002] In fields such as intelligent sensing, environmental monitoring, and biomedical detection, rapid and high-precision detection of solution components (especially ion types and concentrations) has significant application value. Currently, traditional solution ion detection methods mainly include ion chromatography, electrochemical analysis, and spectroscopic analysis. Although these methods have high detection accuracy, they generally have many limitations: ion chromatography and spectroscopic analysis require large, precision instruments, which are bulky, costly, and complex to operate, making rapid on-site detection impossible; electrochemical analysis methods mostly rely on static electrical signals for detection, are easily affected by the solution matrix, and some methods require labeling of the sample, making operation cumbersome and requiring large sample volumes, which is unsuitable for micro-sample detection scenarios.
[0003] With the development of microfluidics and intelligent sensing technologies, droplet detection has become a research hotspot in the field of microanalysis due to its advantages such as small sample volume and fast detection speed. Triboelectric nanogenerators (TENGs), as a novel energy harvesting and signal excitation device, have been widely used in the sensing field due to their simple structure, low cost, and ability to generate high-voltage alternating signals. Droplet nanogenerators (DNGs), as a special type of TENG, use droplets as the core moving parts and can generate electrical signals during droplet impact and flow, thus possessing the advantage of natural compatibility with droplet detection scenarios.
[0004] In the existing technology, there is no technical solution that uses the alternating electric field generated by TENG (including DNG) to excite droplets to produce a dynamic response and achieves high-precision identification of solution ion types and concentrations by detecting the dynamic coupling current signal. In addition, in existing droplet detection devices, if the insulating film used to support the droplets is too thick, the alternating electric field will be severely attenuated in the film, which cannot effectively drive the droplets to produce electromechanical oscillations and interfacial ion responses, thus affecting the detection accuracy and sensitivity. At the same time, existing devices are mostly limited to insulating films of specific materials, with poor compatibility, and cannot be adapted to different types of test solutions, thus limiting their application range.
[0005] Therefore, developing a label-free, sample-volume, rapid, accurate, and highly compatible single-droplet dynamic response detection device and method that can avoid electric field decay and be adapted to various TENG excitation sources, including AC-DNG, has become an urgent technical problem to be solved. Summary of the Invention
[0006] 1. The technical problem to be solved by the present invention
[0007] To address the shortcomings of existing solution ion detection methods, such as bulky equipment, complex operation, large sample volume, labeling requirements, and slow detection speed, as well as the limitations of existing droplet detection devices including severe electric field attenuation, limited insulating film materials, poor compatibility, and single excitation source type, this invention aims to provide a single droplet dynamic response detection device and method based on alternating electric field excitation of a triboelectric nanogenerator. This invention incorporates an AC-DNG droplet nanogenerator into the excitation source range, enabling label-free, low-sample, rapid, accurate, and universal component analysis compatible with various solutions. This provides an innovative solution for the development of rapid on-site detection and portable analytical instruments.
[0008] 2. Technical Solution To achieve the above-mentioned objectives, the present invention adopts the following technical solution: a single droplet dynamic response detection device based on alternating electric field excitation of a triboelectric nanogenerator, comprising an excitation source, an excitation electrode, an insulating film, a sensing electrode, and a signal measurement unit; the excitation source is a triboelectric nanogenerator (TENG) capable of outputting an alternating high-voltage electric signal, including but not limited to contact-separated, sliding, single-electrode, and AC-DNG droplet nanogenerators; the excitation electrode is connected to the excitation source and is used to conduct the high-voltage alternating electric signal; the insulating film is attached to the surface of the excitation electrode and is set to be relatively thin to avoid electric field attenuation and to support the droplet to be tested; the sensing electrode is inserted into the droplet to be tested; the signal measurement unit is connected to the sensing electrode and is used to detect the dynamic coupling current signal generated by the droplet under the alternating electric field in real time.
[0009] Furthermore, the insulating film is a polymer insulating film, including but not limited to fluorinated ethylene propylene (FEP) film, polytetrafluoroethylene (PTFE) film, polyimide (PI) film, and polyethylene terephthalate (PET) film, which can be flexibly selected according to the type of solution to be tested, thereby improving the compatibility of the device.
[0010] Furthermore, the thickness of the insulating film is on the micrometer scale, specifically ranging from 1 μm to 50 μm. This thickness range ensures that the alternating electric field does not decay excessively in the film, while also ensuring that the film has sufficient mechanical strength to stably support the droplets to be tested.
[0011] Furthermore, the AC-DNG outputs transient high-voltage alternating pulse signals during droplet impact or movement, which can be directly used to apply an alternating electric field and drive the droplet to generate a dynamic response without rectification. It is naturally compatible with the detection scenario of the droplet under test, which can improve the integration and scenario adaptability of the device.
[0012] Furthermore, the peak value of the current signal output by the triboelectric nanogenerator is 1μA~15μA, which is suitable for the excitation requirements of droplet forced electromechanical oscillation and interfacial ion dynamic response. Whether it is a conventional TENG or an AC-DNG, its output signal can meet the excitation requirements.
[0013] Furthermore, the excitation electrode is a conductive metal electrode or a flexible conductive thin film electrode. The conductive metal electrode can be made of materials such as copper, aluminum, or gold, while the flexible conductive thin film electrode can be made of materials such as graphene conductive film or carbon nanotube conductive film. The excitation electrode is tightly bonded to the insulating film, with no air bubbles or gaps on the bonding surface, ensuring that the electric field is efficiently conducted to the surface of the insulating film and then acts on the droplet to be tested.
[0014] Furthermore, the test droplet includes ionic solutions, organic reagents, or biological macromolecule solutions, with a droplet volume of 1 μL to 100 μL, enabling the detection of trace samples and reducing sample waste.
[0015] Furthermore, the dynamic coupling current signal is dominated by displacement current and is jointly excited by the forced electromechanical oscillation of the droplet and the dynamic response of interface ions. The signal amplitude ranges from 1nA to 100μA, which facilitates detection by the signal measurement unit and subsequent feature extraction.
[0016] Furthermore, the signal measurement unit includes an electrometer, an oscilloscope, and a data acquisition module. The electrometer is used to acquire the dynamic coupling current signal, the oscilloscope is used to display the signal waveform in real time, and the data acquisition module is used to acquire signal data and transmit it to the subsequent processing unit to realize real-time detection and recording of the signal.
[0017] A method for detecting the dynamic response of a single droplet based on alternating electric field excitation by a triboelectric nanogenerator, implemented using any of the detection devices described above, includes the following steps: S1, Device Debugging: Tightly attach the insulating film to the surface of the excitation electrode, ensuring that there are no air bubbles or gaps on the bonding surface; electrically connect the excitation electrode to the excitation source (a triboelectric nanogenerator capable of outputting alternating high-voltage electrical signals, including but not limited to contact-separation type, sliding type, single-electrode type, and AC-DNG type droplet triboelectric nanogenerators)); insert the sensing electrode into the droplet to be tested; electrically connect the signal measurement unit to the sensing electrode; debug the connection status of each component to ensure that the device is working properly. S2, Electric field excitation and dynamic response: Start the excitation source. If the excitation source is any form of triboelectric nanogenerator, its original transient high-voltage alternating pulse output is used without rectification. The high-voltage alternating signal generated by the excitation source is conducted to the surface of the insulating film through the excitation electrode, forming an alternating electric field at the insulating film-droplet interface. This alternating electric field drives the droplet under test to generate forced electromechanical oscillations, and at the same time excites the ions at the droplet interface to generate a dynamic response. S3 detects in real time the dynamic coupling current signal generated by the forced electromechanical oscillation of droplets and the dynamic response of interface ions through sensing electrodes. This signal is dominated by displacement current and is displayed and acquired. S4, Feature Extraction and Recognition: The acquired dynamic coupling current signal is preprocessed to remove noise interference, and then the time-frequency domain features of the signal are extracted. The time-frequency domain features include one or more of the signal amplitude, frequency, phase, and harmonic components. The extracted time-frequency domain features are input into a trained deep learning model, which includes a convolutional neural network (CNN), a recurrent neural network (RNN), or a combination thereof. The features are analyzed and processed by the deep learning model to achieve high-precision recognition of the types and concentrations of ions in the solution.
[0018] Furthermore, the detection method eliminates the need for labeling the sample, uses only microdroplets, and takes no more than 60 seconds, achieving rapid, label-free detection and improving efficiency. Moreover, the method is applicable to general component analysis of ionic solutions, organic reagents, and biomacromolecule solutions, with an ion concentration recognition accuracy of no less than 1 μmol / L, meeting the detection needs of various scenarios.
[0019] Furthermore, the identification is a fast and high-precision on-site identification. The device has a simple structure, small size, and low cost. It is based on the high-voltage alternating signal excitation of TENG (including AC-DNG), which does not require an additional high-voltage power supply. It is easy to integrate into portable devices and does not require the assistance of large detection instruments, making it suitable for on-site detection scenarios.
[0020] Compared with existing technologies, the QR code image super-resolution reconstruction method based on a complete reference map provided by this invention has the following beneficial effects: (1) This invention proposes and realizes a new detection paradigm for the first time that actively excites droplets to generate dynamic responses based on alternating electric fields generated by TENG (including DNG), and analyzes the dynamic coupling current signal by detecting it. This extends TENG from traditional energy harvesting and passive sensing to the field of active electric field excitation, driving droplets to perform forced electromechanical oscillations and dynamic responses of interface ions, greatly enriching the application potential of TENG in the field of intelligent sensing.
[0021] (2) This invention captures the unique “fingerprint” response (dynamically coupled current signal) of droplets under alternating electric fields, and combines it with deep learning models (CNN, RNN, etc.) to automatically extract and analyze the complex time-frequency domain features of the signal, thereby realizing intelligent and high-precision qualitative and quantitative analysis of solution components, effectively solving the limitations of existing methods in component identification and complex signal analysis. At the same time, by carefully designing an insulating film with a thickness of micrometers (1μm~50μm), the problem of attenuation of alternating electric fields in the medium is effectively solved, ensuring efficient excitation of droplets.
[0022] (3) This invention has significant advantages in detection performance, achieving an ion concentration of not less than 1 μmol / L, far exceeding the challenge of traditional methods for detecting trace ions. Moreover, the amplitude of the dynamic coupling current signal is between 1 nA and 100 μA, ensuring the detectability and analytical value of the signal. The detection time is no more than 60 seconds, providing strong support for rapid on-site detection and real-time monitoring, which is significantly better than traditional methods that require complex pretreatment and long-term analysis. In addition, the detection process does not require any labeling of the sample to be tested, simplifying the operation process and avoiding interference that may be caused by labeling. It only requires a trace droplet of 1 μL to 100 μL, which greatly reduces sample consumption and experimental costs, making it particularly suitable for precious samples or trace analysis scenarios.
[0023] (4) The present invention is outstanding in terms of device adaptability and practicality. It has diversified excitation sources and is compatible with various TENG types (contact separation, sliding, single electrode, and AC-DNG). In particular, DNG is naturally compatible with droplet detection scenarios, which improves the integration. The insulating film material can be customized. The polymer insulating film material can be flexibly selected according to the type of solution to be tested, which ensures the wide applicability of the device to different solution systems, breaks through the limitations of the material of existing devices, and has a wide range of applicable samples. It can perform general component analysis on ionic solutions, organic reagents, and biological macromolecule solutions, which expands the application scenarios.
[0024] (5) The device itself has a simple structure and small size. Relying on the self-generating characteristics of TENG, it does not require an additional high-voltage power supply and is very easy to integrate into portable devices. It is suitable for rapid on-site testing and occasions where large laboratory conditions are lacking. At the same time, compared with large precision instruments, the cost of this invention is significantly reduced, and it has good market promotion potential. Attached Figure Description
[0025] Figure 1 This is a schematic diagram of the single droplet dynamic response detection device based on alternating electric field excitation of a triboelectric nanogenerator according to the present invention.
[0026] Figure 2 This is a schematic diagram of the current signal intensity under different solutions according to the present invention; Figure 3 This is a magnified single-peak schematic diagram of the current peak values of different solutions in this invention; Figure 4 This is a schematic diagram showing the current signal relationship under different excitation electrode radii according to the present invention; Figure 5 This is a schematic diagram illustrating the effect of different insulating film thicknesses on current signals according to the present invention; Figure 6 This is a schematic diagram showing the current variation under different droplet volumes in this invention. Detailed Implementation
[0027] The following detailed description, in conjunction with the accompanying drawings and specific embodiments, provides a method for detecting the dynamic response of droplets based on alternating electric field excitation by a triboelectric nanogenerator, according to the present invention. The following embodiments are used to more clearly illustrate the technical solution of the present invention and do not constitute a limitation on the scope of protection of the present invention.
[0028] Example 1 This embodiment 1 addresses the technical problems of existing solution ion detection methods, such as reliance on large instruments, complex operation, large sample volume, need for labeling, slow detection speed, and severe electric field attenuation, limitations in insulating film material, unstable excitation signal, high sample consumption, and insufficient recognition accuracy in traditional droplet detection devices. The specific operating steps of this solution are as follows: 1. A droplet recognition sensing platform based on the aforementioned generator; Based on the aforementioned droplet triboelectric nanogenerator, this invention further constructs a single-droplet recognition and sensing platform. This platform is mainly used for the recognition and sensing of different types of droplets. Its core improvement lies in using an externally connected, stably operating TENG as the active excitation source, which solves the defects of high sample consumption and unstable signal in existing droplet recognition technologies. The specific structure and working principle are as follows, with corresponding appendices. Figure 1-6 As shown.
[0029] 1.1 The sensor platform structure is as follows: The droplet recognition sensing platform includes an active excitation unit, a shielding unit, a droplet placement unit, conductive electrodes, and a signal measurement unit, as detailed below: The active excitation unit is a stably operating TENG. Figure 1 TENG1 serves as the excitation source for the entire sensing platform. Of the two electrodes of TENG1, one electrode is grounded (to increase the amplitude of the electrical signal and improve the detection sensitivity), and the other electrode is electrically connected to the excitation electrode 2, so that the excitation electrode and the electrode of TENG1 are connected to form an alternating current loop.
[0030] The shielding unit is an insulating film 3 that is tightly attached to the top of the excitation electrode 2. Its function is to shield the alternating current in the excitation electrode 2 and prevent the current from flowing into the droplet to be tested, but it does not affect the penetration of the electric field generated by the excitation electrode 2, so as to realize the effective transmission of the electric field.
[0031] The test droplet placement unit is the upper surface of the insulating film 3, used to place the test droplet 4. The volume of the test droplet can be adjusted according to the detection requirements. In this embodiment, 100 μL is preferred.
[0032] One end of the conductive electrode 5 is inserted into the droplet 4 to be tested, and the other end is electrically connected to the signal measurement unit 6; the signal measurement unit 6 is a 6514 electrometer, which is used to collect and record the current signal modulated by the droplet to be tested.
[0033] 1.2 The working principle of the sensing platform is as follows: The core working principle of this sensing platform is based on the modulation of the excitation electric field by the intrinsic characteristics of the droplet under test. The specific process is as follows: After TENG1 is started and operates stably, its grounding electrode and excitation electrode 2 form an alternating current loop, and the excitation electrode 2 generates a stable alternating electric field. Due to the shielding effect of the insulating film 3, the alternating current in the excitation electrode 2 cannot flow into the test droplet 4 above, but the test droplet 4 can sense the alternating electric field transmitted from the excitation electrode 2 through the insulating film 3.
[0034] The conductive electrode 5 is inserted into the droplet 4 to be tested, and the conductive electrode 5 transmits the electric field signal sensed by the droplet to the 6514 electrometer. Since different types of droplets have different intrinsic properties (such as conductivity, ion concentration, interfacial adsorption, etc.), their modulation effect on the alternating electric field is different, which leads to differences in the current signal collected by the 6514 electrometer. This invention distinguishes and identifies different types of droplets by identifying the differences in the current signal.
[0035] 1.3 Sensor platform performance verification and parameter optimization, as detailed below: To verify the effectiveness of this sensing platform, the following experiment was conducted: Water, sodium chloride solution, and protein solution of the same volume and concentration were selected as test droplets and placed on insulating film 3. The current signal corresponding to each droplet was collected using a 6514 electrometer. The results are as follows: Figure 2 As shown. By Figure 2 It can be seen that, due to the different compositions of the three solutions, the amplitude of their modulated current signals varies significantly, which can initially distinguish the droplet types.
[0036] Further, the current peaks corresponding to the above three solutions were magnified into single-peak diagrams, such as... Figure 3 As shown. By Figure 3 It can be clearly observed that the current peaks corresponding to the three solutions have significant differences in characteristic parameters such as peak height, half-maximum width, and peak area. These differences lay the foundation for accurate droplet identification using deep learning algorithms.
[0037] To optimize the detection performance of the sensing platform, the effects of three key parameters—excitation electrode radius, insulating film thickness, and droplet volume—on the current signal were investigated. Specific experimental results are as follows: (1) Effect of excitation electrode radius: Keeping the insulating film thickness, the volume of the droplet to be tested, and other experimental conditions constant, a comparative experiment was conducted by changing the radius of the excitation electrode. The results are as follows: Figure 4 As shown. By Figure 4 It can be seen that when the radius of the excitation electrode is 1 cm, the amplitude of the current signal collected is the largest, and the detection effect is the best.
[0038] (2) Effect of insulating film thickness: Keeping the excitation electrode radius, the volume of the droplet to be tested, and other experimental conditions constant, a comparative experiment was conducted by changing the thickness of the insulating film. The results are as follows: Figure 5 As shown. By Figure 5 It can be seen that as the thickness of the insulating film increases, the amplitude of the current signal gradually decreases; when the thickness of the insulating film reaches 0.15mm, the amplitude of the current signal is almost 0, and effective detection cannot be achieved.
[0039] (3) Effect of the volume of the test droplet: Keeping the radius of the excitation electrode, the thickness of the insulating film, and other experimental conditions constant, a comparative experiment was conducted by changing the volume of the test droplet, such as... Figure 6 As shown, the results indicate that as the volume of the droplet increases, the amplitude of the current signal continuously increases, and the two are positively correlated.
[0040] 1.4 Supplementary Explanation In this embodiment, an independently operating TENG is selected as the active excitation source. Its output alternating current signal has a large amplitude, which can ensure the detection sensitivity of the sensing platform. It should be noted that the active excitation source can also be an AC droplet nanogenerator (AC-DNG), because DNG is a type of TENG and can also output AC current, which can realize the excitation function of this sensing platform. However, its output current signal amplitude is slightly smaller than that of the TENG selected in this embodiment. Therefore, this embodiment does not supplement the relevant experimental data of AC DNG as the excitation source.
[0041] The droplet recognition sensing platform of this invention can complete the detection with only a single 100μL droplet, eliminating the need for repeated sample addition and effectively reducing sample consumption. It is especially suitable for the detection of valuable samples. At the same time, by using an external TENG as an active excitation source, it avoids the problem of unstable electrical signals generated by droplet friction being easily affected by hydrodynamics in the prior art, which significantly improves the accuracy of the detection results. Moreover, this active excitation method is proposed for the first time.
[0042] To further verify the completeness of this technical solution, this embodiment uses an AC TENG as the excitation source, such as... Figure 1As shown, this embodiment provides a droplet dynamic response detection device based on alternating electric field excitation of a triboelectric nanogenerator (TENG), including an excitation source 1, an excitation electrode 2, an insulating film 3, a droplet to be tested 4, a sensing electrode 5, and a signal measurement unit 6. The excitation source 1 is a TENG, which includes an AC droplet nanogenerator capable of outputting transient high-voltage alternating pulse signals without rectification. The excitation electrode 2 is connected to the TENG electrode and is used to conduct high-voltage alternating electric signals. The insulating film 3 is attached to the surface of the excitation electrode 2 and has a thickness of 10 μm to avoid electric field attenuation and is used to support the droplet to be tested 4. The sensing electrode 5 is inserted into the droplet to be tested 4. The signal measurement unit 6 is connected to the sensing electrode 5 and is used to detect the dynamic coupling current signal generated by the droplet under the alternating electric field in real time.
[0043] In this embodiment, the insulating film 3 is an FEP film, which has good insulation and chemical stability and is suitable for detection of most ion solutions; the excitation electrode 2 is a copper electrode, which is tightly attached to the FEP film with no bubbles or gaps on the bonding surface; the test droplet 4 is a sodium chloride ion solution with a volume of 100 μL; the signal measurement unit 6 is a 6514 electrometer with a sampling rate of 1000.
[0044] The detection method based on the above-mentioned detection device includes the following steps: 1. Device debugging: Tightly attach the FEP film (10μm thick) to the surface of the copper electrode, ensuring that there are no air bubbles or gaps on the bonding surface; connect the copper electrode to the TENG electrode, insert the sensing electrode 5 into 100μL sodium chloride ion solution, connect the signal measurement unit 6 to the sensing electrode 5, and debug the connection status of each component to ensure that the device works normally. 2. Electric field excitation and dynamic response: When the TENG is started, its original transient high-voltage alternating pulse output (without rectification) is used. The TENG generates a peak alternating current signal, which is conducted to the surface of the FEP film through the copper electrode. An alternating electric field is formed at the interface between the FEP film and the sodium chloride solution droplet. This alternating electric field drives the sodium chloride solution droplet to generate forced electromechanical oscillations, and at the same time excites the sodium ions and chloride ions at the droplet interface to generate a dynamic response. 3. Signal detection: The dynamic coupling current signal generated by the forced electromechanical oscillation of the droplet and the dynamic response of the interface ions is detected in real time by the sensing electrode 5. The signal is dominated by displacement current and the signal amplitude ranges from 10nA to 10μA. The signal measurement unit 6 displays the signal and acquires the data. The acquisition time is 30s. 4. Feature Extraction and Recognition: The acquired dynamic coupling current signal is preprocessed. After removing noise interference through a filtering algorithm, the amplitude, frequency, and phase of the signal are extracted. The extracted time-frequency domain features are then input into a trained CNN deep learning model. This model has been trained on sodium chloride solution samples of different concentrations, and the model's recognition accuracy reaches over 98%. The CNN model is used to analyze and process the features, achieving high-precision recognition of the types (sodium ions and chloride ions) and concentrations of ions in sodium chloride solution. The detection time is 45 seconds, and the concentration recognition accuracy is 0.5 μmol / L.
[0045] Example 2 (using a common contact-separated TENG as the excitation source for comparative verification); This embodiment provides a single droplet dynamic response detection device based on alternating electric field excitation of a triboelectric nanogenerator. Its structure is basically the same as that of Embodiment 1, except that: the excitation source 1 is a contact-separated TENG, which outputs an alternating high voltage signal with a peak current of 30μA; the insulating film 3 is a PTFE film with a thickness of 20μm; the excitation electrode 2 is a graphene conductive film electrode; and the droplet to be tested 4 is a lysozyme protein solution (a biological macromolecule solution) with a volume of 50μL. The detection method based on the above detection device is basically the same as that in Example 1, except that: in step 2, the contact separation TENG is activated, and the alternating high voltage signal output by it is conducted to the surface of the PTFE film through the existing insulating film (including graphene film) electrode, driving the glucose solution droplets to generate forced electromechanical oscillations; in step 4, the amplitude and harmonic components of the signal are extracted as two time-frequency domain features, and input into the trained CNN-RNN combined deep learning model to realize the identification of components and concentration detection of glucose solution. The detection time is 35s, and the concentration identification accuracy is 1μmol / L.
[0046] Example 3 (using AC-DNG, with organic reagents to test feasibility); This embodiment provides a droplet dynamic response detection device based on alternating electric field excitation of a triboelectric nanogenerator. Its structure is basically the same as that of Embodiment 1, except that: the excitation source 1 is an AC-DNG, which outputs a transient high-voltage alternating pulse signal with a peak current of 1μA-15μA; the insulating film 3 is a PI film with a thickness of 50μm; the excitation electrode 2 is an aluminum electrode; and the droplet to be tested 4 is an ethanol solution (organic reagent) with a volume of 100μL. The above three embodiments all demonstrate that the detection device and method of the present invention, regardless of whether AC-DNG or ordinary TENG is used as the excitation source, can achieve label-free, trace-volume, rapid and accurate detection of solution components. The thin insulating film has a reasonable thickness, avoiding electric field attenuation, and is compatible with different types of solutions, making it widely applicable in rapid on-site detection scenarios and providing strong support for the development of portable analytical instruments. In particular, when AC-DNG is used as the excitation source, it is naturally compatible with droplet detection scenarios, requiring no rectification processing, further improving the integration and practicality of the device.
[0047] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A single-droplet dynamic response detection device based on alternating electric field excitation of a triboelectric nanogenerator, characterized in that, It includes a self-driven alternating high-voltage excitation source, excitation electrodes, insulating thin film, sensing electrodes, and signal measurement unit; The self-driven alternating high voltage excitation source is a triboelectric nanogenerator (TENG) capable of outputting alternating high voltage electrical signals, including but not limited to contact-separated, sliding, single-electrode, and AC-DNG droplet nanogenerators. It can directly output transient high voltage alternating pulses without rectification, achieving in-situ matching excitation with the dynamic response of the droplet. The excitation electrode is connected to a self-driven alternating high-voltage excitation source and is used to conduct high-voltage alternating electrical signals; the excitation electrode is a conductive metal electrode or a flexible conductive thin film electrode. The insulating film is bubble-free and gapless, tightly bonded to the excitation electrode to ensure efficient electric field conduction; and its thickness is set to be relatively thin to avoid electric field attenuation, in order to hold the droplet to be tested. The sensing electrode is inserted into the droplet to be tested; the signal measurement unit is connected to the sensing electrode and is used to detect the dynamic coupling current signal generated by the droplet under the alternating electric field in real time.
2. The device for detecting the dynamic response of a single droplet excited by an alternating electric field of a triboelectric nanogenerator according to claim 1, characterized in that, The insulating film is a polymer insulating film, including but not limited to fluorinated ethylene propylene (FEP) film, polytetrafluoroethylene (PTFE) film, polyimide (PI) film, and polyethylene terephthalate (PET) film.
3. The device for detecting the dynamic response of a single droplet excited by an alternating electric field of a triboelectric nanogenerator according to claim 1, characterized in that, The thickness of the insulating film is on the micrometer scale, ranging from 1 μm to 50 μm, to ensure that the electric field does not decay excessively within the film.
4. The droplet dynamic response detection device based on alternating electric field excitation of a triboelectric nanogenerator according to claim 1, characterized in that, The AC-DNG (Alternating Current Droplet Nanogenerator) outputs transient high-voltage alternating pulse signals during droplet impact or movement, which can be directly used to apply an alternating electric field and drive the droplet to generate a dynamic response without rectification.
5. The single-droplet dynamic response detection device based on alternating electric field excitation of a triboelectric nanogenerator according to claim 1, characterized in that, The triboelectric nanogenerator (TENG) is any one of contact-separated, sliding, or single-electrode TENGs, used to provide alternating high-voltage excitation signals.
6. The single-droplet dynamic response detection device based on alternating electric field excitation of a triboelectric nanogenerator according to claim 1, characterized in that, The excitation electrode is a conductive metal electrode or a flexible conductive thin film electrode, which is tightly bonded to the insulating film. The bonding surface is free of bubbles and gaps, ensuring efficient conduction of the electric field.
7. The single-droplet dynamic response detection device based on alternating electric field excitation of a triboelectric nanogenerator according to claim 1, characterized in that, The test droplet includes ionic solutions, organic reagents, or biological macromolecule solutions, with a droplet volume of 1 μL to 100 μL.
8. The single-droplet dynamic response detection device based on alternating electric field excitation of a triboelectric nanogenerator according to claim 1, characterized in that, The dynamic coupling current signal is dominated by displacement current and is jointly excited by the forced electromechanical oscillation of the droplet and the dynamic response of interface ions, with a signal amplitude range of 1nA to 100μA.
9. A method for detecting the dynamic response of a droplet based on alternating electric field excitation by a triboelectric nanogenerator, characterized in that, The droplet dynamic response detection device based on the alternating electric field excitation of a triboelectric nanogenerator as described in any one of claims 1 to 8 includes the following steps: S1, Device debugging: The 1μm~50μm polymer insulating film is tightly bonded to the excitation electrode without bubbles or gaps. The excitation electrode is connected to the self-driven TENG excitation source. The sensing electrode is inserted into the 1μL~100μL droplet to be tested. The signal measurement unit is connected to the sensing electrode and debugged. S2, Electric field excitation and dynamic response: The TENG excitation source is activated, and the AC DNG maintains the original transient high voltage alternating pulse output without rectification. An alternating electric field is formed at the interface between the insulating film and the droplet, which drives the droplet to generate forced electromechanical oscillations and excites the dynamic response of interface ions. S3, Signal Detection: Real-time detection, display, and acquisition of dynamic coupling current signals dominated by displacement current through sensing electrodes; S4, Feature Extraction and Recognition: After denoising the signal, extract one or more time-frequency domain features, including amplitude, frequency, phase, and harmonic components, and input them into a trained CNN, RNN, or a combination of deep learning models to achieve high-precision recognition of the types and concentrations of ions in the solution.
10. The detection method according to claim 9, characterized in that, No labeling of the sample is required, the sample volume is on the order of microdroplets, and the detection time is no more than 300 seconds.
11. The detection method according to claim 9, characterized in that, The method is applicable to general component analysis of ionic solutions, organic reagents and biological macromolecule solutions, with an ion concentration recognition accuracy of not less than 1 μmol / L.
12. The detection method according to claim 9, characterized in that, The identification is a rapid and high-precision on-site identification method that can be used in portable analysis and detection scenarios without the need for large-scale detection instruments.