阅读说明：本技术 扫描电化学显微镜系统及其控制方法 (Scanning electrochemical microscope system and control method thereof ) 是由 刘振邦 牛利 马英明 包宇 王伟 韩冬雪 何颖 于 2020-07-28 设计创作，主要内容包括：本发明公开了一种扫描电化学显微镜系统及其控制方法,应用在扫描电化学显微镜技术之中,系统包括：探针,用于检测电信号；探针定位系统,用于驱动所述探针移动；双恒电位仪,用于向所述探针施加测试信号并检测所述探针的反馈信号；计算机,用于控制所述探针定位系统驱动所述探针移动；以及控制所述双恒电位仪在所述探针停留在一个检测位置时,向所述探针施加长时间的电位或至少两个具有不同电位等级的测试信号,以及记录每个测试信号对应的所述反馈信号；以及根据电位等级相同的所有检测位置的反馈信号得到各电位等级所对应的扫描图像。本发明相对于现有技术效率更高,并且每次扫描可以获得更加多的测试数据。(The invention discloses a scanning electrochemical microscope system and a control method thereof, which are applied to the scanning electrochemical microscope technology, and the system comprises: a probe for detecting an electrical signal; the probe positioning system is used for driving the probe to move; a double potentiostat for applying a test signal to the probe and detecting a feedback signal from the probe; the computer is used for controlling the probe positioning system to drive the probe to move; controlling the double potentiostats to apply a long-time potential or at least two test signals with different potential levels to the probes when the probes stay at a detection position, and recording the feedback signals corresponding to each test signal; and obtaining a scanning image corresponding to each potential grade according to the feedback signals of all the detection positions with the same potential grade. Compared with the prior art, the method has higher efficiency, and more test data can be obtained in each scanning.)

1. A scanning electrochemical microscope system, comprising:

a probe for detecting an electrical signal;

the probe positioning system is used for driving the probe to move;

a double potentiostat for applying a test signal to the probe and detecting a feedback signal from the probe;

the computer is used for controlling the probe positioning system to drive the probe to move; controlling the double potentiostats to apply at least two test signals with different potential levels to the probes in sequence when the probes stay at a detection position, and recording the feedback signals corresponding to each test signal; obtaining a scanning image corresponding to each potential grade according to the feedback signals of all detection positions with the same potential grade; wherein the holding time of each test signal is the same.

2. The scanning electrochemical microscope system of claim 1, wherein the computer is further configured to obtain configuration parameters specifying a movement area of the probe, a movement step, a test signal, and a variation law of a potential level of the test signal.

3. The scanning electrochemical microscope system of claim 2, wherein the computer is further configured to arrange the scanned images corresponding to different potential levels according to a variation rule of the potential levels of the test signal to form a time-sequential image sequence.

4. The scanning electrochemical microscope system of claim 3, wherein the computer is further configured to obtain an input instruction, determine a selected time based on the input instruction, and display a scanned image corresponding to the selected time.

5. The scanning electrochemical microscope system of claim 1, wherein the test signal has a waveform that is at least one of a linear waveform, a stepped waveform, or a combination of a linear waveform and a stepped waveform.

6. The scanning electrochemical microscope system of claim 1, wherein the dual potentiostat comprises a working electrode, a reference electrode, and a counter electrode, wherein the working electrode is connected to the probe, and the reference electrode and the counter electrode are for placement in an electrolyte solution.

7. A method of controlling a scanning electrochemical microscope system as claimed in claim 1, comprising the steps of:

acquiring configuration parameters;

controlling the probe to move according to the configuration parameters;

when the probe stays at a detection position, at least two test signals with different potential levels are sequentially applied to the probe, and the feedback signal corresponding to each test signal is recorded; wherein, the maintaining time of each test signal is the same;

and obtaining a scanning image corresponding to each potential grade according to the feedback signals of all the detection positions with the same potential grade.

8. The method of claim 7, wherein the configuration parameters are used to specify a moving area of the probe, a moving step, a test signal, and a variation law of a potential level of the test signal.

9. The method of controlling a scanning electrochemical microscope system of claim 8, further comprising the steps of:

and arranging the scanning images corresponding to different potential levels according to the change rule of the potential levels of the test signals to form an image sequence arranged in time sequence.

10. The method of controlling a scanning electrochemical microscope system of claim 7, further comprising the steps of:

acquiring an input instruction, determining a selected time according to the input instruction, and displaying a scanned image corresponding to the selected time.

Technical Field

The invention relates to a scanning electrochemical microscope technology, in particular to a scanning electrochemical microscope system and a control method thereof.

Background

Scanning Electrochemical Microscope (SECM) is a Scanning Tunneling Microscope (STM) technique that Bard et al use for reference to perform Electrochemical measurement information collection and measurement at a micro-scale space position. The SECM can not only study heterogeneous reaction kinetics of the scanning probe and the substrate and homogeneous reaction kinetics in the solution, but also distinguish electrochemical nonuniformity of micro-regions on the surface of the electrode, give the appearance of the surface of a conductor and an insulator, even carry out micro-processing on materials, study a plurality of important biological processes and the like. SECM is a reality since it is being investigated for pharmacological release, phase transfer catalysis, dynamic processes, etc.

For SECM experiments, the most common detection mode is the positive and negative feedback mode. The feedback working mode is mainly used for determining the height of the probe relative to the measured substrate, and is divided into a positive feedback mode and a negative feedback mode, and the positive feedback mode and the negative feedback mode are mainly distinguished according to the fact that the current increases or decreases when the probe approaches the measured substrate. When the distance between the probe and the substrate is small to a certain extent, the current changes dramatically, and if a conductor is arranged below the probe, the current rises rapidly, and otherwise, the current drops rapidly. The positive and negative feedback mode is the main method for collecting current, by which the scanning probe can be moved down to a distance close enough to the substrate, and the scanning probe is controlled to move by a stepping motor or a piezoelectric crystal. The upper computer software can generate a matrix scanning area according to the set parameters such as the displacement direction, the displacement distance (horizontal and longitudinal displacement), the moving speed, the displacement distance and the like, and current collection is carried out in the scanning area. An area scan of the substrate at this height yields an image of the electrochemical activity of the substrate. The actual imaging measurement is then the result of a combination of the electrochemical properties and physical topography of the substrate.

However, the current SECM system can only perform single image scanning at a fixed potential, which is inefficient, and provides less test data and single information per scanning.

Disclosure of Invention

To solve at least one of the above-mentioned technical problems, the present invention is directed to: a scanning electrochemical microscope system and a control method thereof are provided, which can generate a plurality of image frames in one scanning cycle, increase scanning efficiency and provide more test data in one scanning cycle.

In a first aspect, an embodiment of the present invention provides:

a scanning electrochemical microscope system, comprising:

a probe for detecting an electrical signal;

an electrolytic vessel for holding the solution and the test sample;

the probe positioning system is used for driving the probe to move;

a double potentiostat for applying a test signal to the probe and detecting a feedback signal from the probe;

the computer is used for controlling the probe positioning system to drive the probe to move; controlling the double potentiostats to apply at least two test signals with different potential levels to the probes in sequence when the probes stay at a detection position, and recording the feedback signals corresponding to each test signal; obtaining a scanning image corresponding to each potential grade according to the feedback signals of all detection positions with the same potential grade; wherein the holding time of each test signal is the same.

Further, the computer is further configured to obtain configuration parameters, where the configuration parameters are used to specify a movement region, a movement step, a test signal, and a variation rule of a potential level of the test signal of the probe.

Further, the computer is also used for arranging the scanning images corresponding to different potential levels according to the change rule of the potential levels of the test signals so as to form an image sequence arranged in time sequence.

Further, the computer is also used for acquiring an input instruction, determining the selected time according to the input instruction, and displaying the scanned image corresponding to the selected time.

Further, the waveform of the test signal is at least one of a linear waveform, a step waveform, or a combination of a linear waveform and a step waveform.

Further, the double potentiostat comprises a working electrode, a reference electrode and a counter electrode, wherein the working electrode is connected with the probe, and the reference electrode and the counter electrode are used for being placed in an electrolyte solution.

In a second aspect, an embodiment of the present invention provides:

a method of controlling a scanning electrochemical microscope system, comprising the steps of:

acquiring configuration parameters;

controlling the probe positioning system to drive the probe to move according to the configuration parameters;

controlling the double potentiostats to apply at least two test signals with different potential levels to the probes in sequence when the probes stay at a detection position, and recording the feedback signals corresponding to each test signal; wherein, the maintaining time of each test signal is the same;

and obtaining a scanning image corresponding to each potential grade according to the feedback signals of all the detection positions with the same potential grade.

Further, the configuration parameters are used for specifying a movement area, a movement step, a test signal of the probe and a change rule of a potential level of the test signal.

Further, the method also comprises the following steps:

and arranging the scanning images corresponding to different potential levels according to the change rule of the potential levels of the test signals to form an image sequence arranged in time sequence.

Further, the method also comprises the following steps:

acquiring an input instruction, determining a selected time according to the input instruction, and displaying a scanned image corresponding to the selected time.

The embodiment of the invention has the beneficial effects that: the invention applies the test signals with different potential levels to the same test position and records the corresponding feedback signals, thus forming the scanning images corresponding to the test signals with different potential levels through one-time scanning.

Drawings

FIG. 1 is a schematic diagram of a scanning electrochemical microscope system according to an embodiment of the present invention;

FIG. 2 is a waveform diagram of a test signal of cyclic voltammetry provided according to an embodiment of the present invention;

FIG. 3 is a waveform diagram of a test signal of square wave voltammetry provided according to an embodiment of the invention;

FIG. 4 is a waveform diagram of a test signal of a linear voltammetry method according to an embodiment of the present invention;

FIG. 5 is a flowchart of a method for controlling a scanning electrochemical microscope system according to an embodiment of the present invention;

fig. 6 is a flowchart of another control method for a scanning electrochemical microscope system according to an embodiment of the present invention.

Detailed Description

The invention is further described with reference to the drawings and the specific examples.

Referring to fig. 1, the present embodiment discloses a scanning electrochemical microscope system, which includes:

a probe 101 for detecting an electrical signal, the probe being a SECM microprobe.

An electrochemical detection cell 102 for carrying an electrolyte solution and a test sample 106; the shape of the device can be changed according to actual needs.

A probe positioning system 103 for driving the probe to move; in this embodiment, the probe positioning system may include a stepper motor and a piezoelectric crystal.

A double potentiostat 104 comprising a working electrode 1041, a reference electrode 1042, a counter electrode 1043 for applying a test signal to the probe 101 and detecting a feedback signal from the probe; usually, a long column, which is half as thin as the reference electrode, is applied to the counter electrode, and a long platinum wire is connected to the lower side.

A computer 105 for controlling the probe positioning system to drive the probe to move; controlling the double potentiostats to apply at least two test signals with different potential levels to the probes in sequence when the probes stay at a detection position, and recording the feedback signals corresponding to each test signal; and obtaining a scanning image corresponding to each potential grade according to the feedback signals of all the detection positions with the same potential grade. Wherein the holding time of each test signal is the same.

In this embodiment, the user can set the moving range and the moving step of the probe 101 through the computer 105. The range of motion and the size of the moving step determine the resolution, and the computer drives the probe to move over each test location by controlling the probe positioning system. And controlling the double potentiostats to output test signals of a plurality of potential levels at each test position. It should be understood that the test signal may be a signal having a certain waveform, and the potential level may be used to characterize the average potential of the signal.

By the embodiment, the test signal of a plurality of potential levels can be adopted for testing in one scanning period, so that scanning images corresponding to the potential levels are formed, and after the scanning images are arranged according to the time sequence, the time attribute of the test can be reflected. Compared with the prior art, the embodiment can expand the application field range, increase the scanning efficiency and obtain more test data in each scanning. In addition, compared with the prior art, different testing methods can be applied to different measurement systems on the premise of acquiring the same data volume, the moving times of the probe are reduced, and the service life of the device is prolonged.

In some embodiments, the computer is further configured to obtain configuration parameters for specifying a movement area of the probe, a movement step, a test signal, and a variation rule of a potential level of the test signal.

In this embodiment, the user may input configuration parameters to the computer through an input device such as a keyboard, a touch screen, or a mobile phone, and these configuration parameters may be used to specify the movement region of the probe, where the movement region may be described in terms of system coordinates in this embodiment. The configuration parameters may also be used to configure the movement steps of the probe, which refers to the distance the probe moves each time. Designating a test signal in this embodiment refers to designating a test type or designating a waveform of the test signal. The change rule of the potential level of the test signal refers to the trend of the potential level with time, in this embodiment, a set time is generally used to maintain a potential level, and it should be understood that the potential level is a level for the whole test signal, which means that the potential level can be changed in a signal.

In some embodiments, the computer is further configured to arrange the scanned images corresponding to different potential levels according to a change rule of the potential levels of the test signal to form an image sequence arranged in time-series.

In the present embodiment, the potential level may be changed at a certain period, and for example, the potential level may be maintained for 0.1 second from 1V, 2V to 3V on average, respectively. Therefore, three scanning images corresponding to 1V, 2V and 3V are generated, and the objects are arranged according to the generated sequence, so that the information of the time dimension can be generated. In some embodiments, where the sampling rate is sufficiently high, the number of potential levels can be considered infinite, and the change in potential level can be considered linear. For example, it is continuously changed from 1V to 3V, so that a continuously changed scanned image can be generated. The embodiment can facilitate the user to select the scanning image to be observed according to the potential level or time.

In some embodiments, the computer is further configured to obtain an input instruction, determine a selected time according to the input instruction, and display a scanned image corresponding to the selected time.

In this embodiment, based on the selection of the user on the test time, the scan image corresponding to the time point is screened out and displayed. So that the user can observe the scanned image at a certain point of time.

In some embodiments, the waveform of the test signal is at least one of a linear waveform, a step waveform, or a combination of a linear waveform and a step waveform.

Referring to FIG. 2, a test signal waveform of cyclic voltammetry is shown. Referring to fig. 3, a waveform diagram of a test signal of a square wave voltammetry is shown. Referring to fig. 4, a waveform diagram of a test signal of a linear voltammetry is shown. As described above, the waveform of the test signal may be a potential signal having a certain period of time, and may be a linear waveform, a step waveform, or a combined signal of a linear waveform and a step waveform. Different test waveforms can be selected according to experiment requirements.

Referring to fig. 1, in some embodiments, the dual potentiostat comprises a working electrode, a reference electrode, and a counter electrode, wherein the working electrode is connected to the probe, and the reference electrode and the counter electrode are for placement in an electrolyte solution. By configuring the reference electrode, the accuracy of the applied potential of the dual potentiostat can be increased.

Referring to fig. 5, the embodiment discloses a control method of a scanning electrochemical microscope system, which is applied in a computer of the system and comprises the following steps:

step 510, obtaining configuration parameters; in this embodiment, the method is used for specifying the moving area of the probe, the moving step, the test signal and the change rule of the potential level of the test signal.

And step 520, controlling the probe positioning system to drive the probe to move according to the configuration parameters.

Specifically, the computer controls the probe positioning system to drive the probe to move to each test position in the moving area according to the moving steps according to the configuration parameters.

Step 530, controlling the double potentiostats to apply at least two test signals with different potential levels to the probes in sequence when the probes stay at a detection position, and recording the feedback signals corresponding to each test signal; wherein the holding time of each test signal is the same.

By recording the feedback signals corresponding to a plurality of potential levels, scanned images corresponding to different potential levels can be formed.

And 540, obtaining a scanning image corresponding to each potential level according to the feedback signals of all the detection positions with the same potential level.

In this step, it is assumed that there are A, B, C, D test positions, and three test signals of potential levels are set for each test position, and three feedback signals a1, a2, and A3 are obtained for point a, three feedback signals B1, B2, and B3 are obtained for point B, three feedback signals C1, C2, and C3 are obtained for point C, and three feedback signals D1, D2, and D3 are obtained for point D. Wherein the feedback signals are obtained in the order of A1, A2, A3, B1, B2, B3, C1, C2, C3, D1, D2 and D3. Therefore, the scanning object corresponding to the first potential level can be obtained based on the four feedback signals a1, B1, C1 and D1, the scanning object corresponding to the second potential level can be obtained based on the four feedback signals a2, B2, C2 and D2, and the scanning object corresponding to the third potential level can be obtained based on the four feedback signals A3, B3, C3 and D3.

From the above embodiments, by performing a test on multiple potential levels for each point, a scan image corresponding to multiple different potential levels can be obtained in one scan period, and different potential levels have practical values for different experimental systems, for example, higher accuracy can be obtained by performing enrichment and then detection on the potential, and more test data can be obtained in one scan period.

In some embodiments, the configuration parameters are used to specify a movement region of the probe, a movement step, a test signal, and a variation rule of a potential level of the test signal.

In some embodiments, further comprising the steps of:

and arranging the scanning images corresponding to different potential levels according to the change rule of the potential levels of the test signals to form an image sequence arranged in time sequence.

In some embodiments, further comprising the steps of:

acquiring an input instruction, determining a selected time according to the input instruction, and displaying a scanned image corresponding to the selected time.

Referring to fig. 6, the present embodiment discloses a control method of a scanning electrochemical microscope system, which includes the following main steps:

after the probe approaches the substrate through the asymptotic curve, parameters of a scanning area of the scanning probe, such as the moving step length, the moving direction, the distance in the X direction, the distance in the Y direction, the stopping time after displacement and the like, are set. The scanning parameters are set to mainly generate a displacement matrix of the scanning probe, the matrix is composed of a plurality of scanning points, and then a scanning area is established.

The combined electrochemical experiments to be performed at each scanning point in the scanning area are selected, and the combined electrochemical experiments can only select experiments with quantifiable running time, such as CV, LSV, ITC and the like. The purpose of this step is to perform a fixed run-time electrochemical experimental procedure at each scan point. The electrochemical experimental method is to apply a fixed waveform according to set parameters, collect related current and voltage signals or process the collected signals.

And running the experiment, and generating an executed task sequence by the upper computer according to the selected combined experiment and the scanning area setting. The execution sequence firstly judges whether the displacement is finished or not, the combined experiment is carried out until the experiment is finished and the experiment data is stored, and the scanning probe carries out the displacement until the whole scanning range is finished.

After the experiment is completed, the experimental data of all the scanning points are processed, and each point adopts the same electrochemical experiment, and the electrochemical experiment can be quantified through time. The data were collated with experimental time and a time axis was added. The length of the time axis is the running time length of the electrochemical experiment selected for combination.

And (3) acquiring data corresponding to the time node of each combined experiment by inputting a time parameter by a user, and drawing the data into a thermodynamic diagram, wherein the thermodynamic diagram comprises a three-dimensional data axis, and X, Y is used for acquiring data points for the combined experiment corresponding to each scanning point by a displacement distance and a Z axis.

Different methods can be applied to better analyze different research systems. The time resolution of the scanning electrochemical microscope can be increased by adding the time shaft, and then the scanning area is analyzed.

In the above embodiment, the electrochemical experiment scanning is performed at each scanning point, the time of the electrochemical data used in combination is quantified, and the collected data is obtained in the electrochemical experiment used in combination with the input time, that is, the data is extracted from the experiment at each measuring point at the same time to form a "frame" of data. By the method, a frame of data can be observed independently, or the change of the acquired data of a scanning area can be observed dynamically.

According to the invention, the time resolution of originally planarized scanning electrochemical data can be increased, and the application range of the scanning electrochemical microscope can be widened.

The step numbers in the above method embodiments are set for convenience of illustration only, the order between the steps is not limited at all, and the execution order of each step in the embodiments can be adapted according to the understanding of those skilled in the art.

While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.