KR102620806B1 - Fully digitally operating shear-force atomic force microscopy and operation method - Google Patents

Abstract

A digitized shear force atomic force microscope and method of operation are disclosed. According to an embodiment of the present invention, a digitized shear force atomic force microscope includes DAQ (Data AcQuisition) that outputs a digital sine wave, excites it with a tuning fork, and measures the electrical signal from the tuning fork; And it may include a computer that removes noise different from the reference frequency from the measured electrical signal through a digital lock-in amplifier.

Description

FULLY DIGITALLY OPERATING SHEAR-FORCE ATOMIC FORCE MICROSCOPY AND OPERATION METHOD}

The technical field to which the present invention belongs may be mechanical and electrical/electronic fields.

The present invention utilizes DAQ (Data Acquisition) to digitize shear force, allowing the function generator and lock-in amplifier to be omitted in shear force atomic force microscopy. It relates to atomic force microscopes and operating methods.

Here, the shear force acts in parallel, but the direction of the force may refer to a force that acts in the opposite direction.

Additionally, DAQ (Data AcQuisition) can be a means of real-world sampling to generate data that can be manipulated by a computer.

The operating method of a conventional shear force atomic force microscope (AFM) is that an analog function generator generates a sine-shaped electric wave, and a tuning fork that resonates with this electric wave sends out different electric signals depending on the distance between the probe and the sample. It works accordingly.

The electrical signal emitted from the tuning fork is very small and contains a lot of noise, so it can be amplified by a preamplifier.

The lock-in amplifier uses the frequency of the electric wave generated by the analog function generator as the reference frequency and removes noise from the electric signal coming from the tuning fork. Based on the electrical signal from which noise has been removed, the distance between the probe and the sample is adjusted to several nanometers through PZT.

In a conventional shear force atomic force microscope, an analog function generator, an analog lock-in amplifier, and an analog PID (Process IDentifier) are essential.

The cost of these products, which must be provided in a conventional shear force atomic force microscope, is problematic from an economic perspective because they occupy a significant portion of the atomic force microscope.

Therefore, the emergence of a digitally operated shear force atomic force microscope is urgently needed.

An embodiment of the present invention replaces the function generator and lock-in amplifier with a computer, digitizing the existing analog method of processing signals, while maintaining a level of precision that can be used in a shear force atomic force microscope (AFM). , the problem is to provide a digitized shear force atomic force microscope and operation method.

In addition, an embodiment of the present invention has another purpose in shear force atomic force microscopy (AFM), by replacing the analog function generator, analog lock-in amplifier, and analog PID with a computer and enabling digital processing.

According to an embodiment of the present invention, a digitized shear force atomic force microscope includes DAQ (Dta AcQuisition) that outputs a digital sine wave, excites it with a tuning fork, and measures the electrical signal from the tuning fork; And it may include a computer that removes noise different from the reference frequency from the measured electrical signal through a digital lock-in amplifier.

In addition, a method of operating a digitized shear force atomic force microscope according to an embodiment of the present invention includes the steps of outputting a digital sine wave from the DAQ and exciting it with a tuning fork; In the DAQ, measuring an electrical signal from the tuning fork; and, in a computer, removing noise different from the reference frequency from the measured electrical signal through a digital lock-in amplifier operation.

According to one embodiment of the present invention, the function generator and lock-in amplifier are replaced with a computer, digitizing the existing analog signal processing method, while maintaining a level of precision that can be used in a shear force atomic force microscope (AFM). It is possible to provide a digitized shear force atomic force microscope and a method of operation, which provides a digitized shear force atomic force microscope and a method of operation.

Additionally, according to an embodiment of the present invention, in a shear force atomic force microscope (AFM), the analog function generator, analog lock-in amplifier, and analog PID can be replaced with a computer and processed digitally.

In addition, according to an embodiment of the present invention, Tip-enhanced Raman Spectroscopy (TERS) measurement, which can also be performed in analog, can be performed through a sufficiently stable shear force atomic force microscope. This TERS measurement is a near-field measurement that can determine the optical properties of a material.

Figure 1 is a block diagram showing the configuration of a digitized shear force atomic force microscope according to an embodiment of the present invention.
Figure 2 is a configuration diagram for explaining the digitized shear force atomic force microscope of the present invention.
Figure 3 is a gap dependence and time series, Figure 3(a) is a gap dependence showing feedback stability, and Figure 3(b) is a time series showing the stability that can maintain TERS.
Figure 4 is a diagram showing an example of TERS.
Figure 5 is a diagram to explain how digital lock-in works.
Figure 6 is a flowchart showing a method of operating a digitized shear force atomic force microscope according to an embodiment of the present invention.

Hereinafter, embodiments will be described in detail with reference to the attached drawings. However, various changes can be made to the embodiments, so the scope of the patent application is not limited or limited by these embodiments. It should be understood that all changes, equivalents, or substitutes for the embodiments are included in the scope of rights.

The terms used in the examples are for descriptive purposes only and should not be construed as limiting. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “comprise” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by a person of ordinary skill in the technical field to which the embodiments belong. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless explicitly defined in the present application, should not be interpreted in an ideal or excessively formal sense. No.

In addition, when describing with reference to the accompanying drawings, identical components will be assigned the same reference numerals regardless of the reference numerals, and overlapping descriptions thereof will be omitted. In describing the embodiments, if it is determined that detailed descriptions of related known technologies may unnecessarily obscure the gist of the embodiments, the detailed descriptions are omitted.

Figure 1 is a block diagram showing the configuration of a digitized shear force atomic force microscope according to an embodiment of the present invention.

Referring to FIG. 1, a digitized shear force atomic force microscope 100 according to an embodiment of the present invention may be configured to include a data acquisition (DAQ) 110 and a computer 120. Additionally, depending on the embodiment, the digitized shear force atomic force microscope 100 may be configured by selectively adding a preamplifier 130 and a tuning fork 140.

The DAQ (110) outputs a digital sine wave and excites it with the tuning fork (140). In other words, the DAQ 110 oscillates a sine-shaped digital wave to the tuning fork 140, allowing the probe mounted on the tuning fork 140 to detect a sample, which is an object.

The tuning fork 140 is a device that outputs a waveform of a certain frequency. As it is excited and resonates with the input digital sine wave, a shear force according to the distance between the samples is applied, and the tuning fork 140 has a different amplitude depending on the distance between the sample and the tip. By outputting a sine wave, the height information of the sample can be known, and through this, the sample can be detected. The tuning fork 140 can be configured to include a tip and PZT.

In the output of the digital sine wave, the DAQ (110) converts the virtual waveform created by the program in the computer into an electric wave of a frequency that causes the tuning fork 140 to be in a resonance vibration state and outputs it as the digital sine wave. You can. In other words, the DAQ 110 can drive and output a virtual sine wave produced by programming at a specified frequency. At this time, the frequency at which the virtual waveform is driven may be a frequency that causes the tuning fork 140 to enter a resonance vibration state, that is, the same frequency as the natural frequency of the tuning fork 140 itself.

Additionally, the DAQ 110 measures the electrical signal from the tuning fork 140. In other words, the DAQ 110 can serve to receive input and measure when a sample is detected at the tuning fork 140 in a resonant vibration state by a digital sine wave and the electrical signal changes.

The computer 120 removes noise different from the reference frequency from the measured electrical signal through a digital lock-in amplifier. In other words, the computer 120 may serve to filter noise by removing frequency regions that deviate from a set standard from the electrical signal collected through the DAQ 110.

Here, the reference frequency may be determined by the frequency of the digital sine wave output from the DAQ (110) and excited by the tuning fork (140).

Depending on the embodiment, the digitized shear force atomic force microscope 100 may obtain more accurate height information of the sample by amplifying the electrical signal collected from the tuning fork 140.

To this end, the digitized shear force atomic force microscope 100 may be configured to include a preamplifier 130.

That is, the preamplifier 130 can amplify the electrical signal input from the tuning fork 140 and enable measurement by the DAQ. Through this, the preamplifier 130 can amplify low-level electrical signals to make noise removal easier.

In addition, as the digital lock-in amplifier function, the computer 120 can multiply the amplified electrical signal and a sine-shaped and cosine-shaped virtual wave created according to the sample rate recognized by the DAQ.

The computer 120 demodulates the height information of the tuning fork 140 received from the DAQ 110 into a sine wave and a cosine wave in an array format at the same sample rate as the signal received inside the computer code and multiplies them. By doing so, the digital lock-in amplifier function can be performed.

Additionally, the computer 120 can adjust the gap between the sample and the probe of the tuning fork 140 through digital PID control, based on the electrical signal from which the noise has been removed. That is, the computer 120 removes noise different from the reference frequency through a digital lock-in amplifier operation, and adjusts the gap between the sample and the probe to several nanometers through digital PID control based on the noise-removed electrical signal. You can give feedback.

At this time, the probe of the tuning fork 140 includes at least one of silicon, gold, and tungsten, thereby improving detection precision.

According to one embodiment of the present invention, the function generator and lock-in amplifier are replaced with a computer, digitizing the existing analog signal processing method, while maintaining a level of precision that can be used in a shear force atomic force microscope (AFM). It is possible to provide a digitized shear force atomic force microscope and a method of operation, which provides a digitized shear force atomic force microscope and a method of operation.

Additionally, according to an embodiment of the present invention, in a shear force atomic force microscope (AFM), the analog function generator, analog lock-in amplifier, and analog PID can be replaced with a computer and processed digitally.

In addition, according to an embodiment of the present invention, Tip-enhanced Raman Spectroscopy (TERS) measurement, which can also be performed in analog, can be performed through a sufficiently stable shear force atomic force microscope. This TERS measurement is a near-field measurement that can determine the optical properties of a material.

Figure 2 is a configuration diagram for explaining the digitized shear force atomic force microscope of the present invention.

As shown in FIG. 2, the digitized shear force atomic force microscope 100 of the present invention can be configured to include a tuning fork (tip assembly), a PZT scanner, and a digital control module & AFM scanning program (DAQ).

The digitized shear force atomic force microscope 100 may include a feedback device that adjusts the gap between the tuning fork of the pointed probe and the sample with a precision of about 0.2 nm.

The digitized shear force atomic force microscope (100), unlike the existing analog method, generates a sine-shaped electric wave like a function generator through DAQ using a virtual waveform created by a computer program and excites it with a tuning fork equipped with a probe. Tuning fork can be put into resonance vibration state.

The digitized shear force atomic force microscope (100) can amplify the signal from the tuning fork through a preamplifier and then directly measure it through DAQ (signal detection).

The digitized shear force atomic force microscope (100) can remove noise different from the reference frequency from the measured signal of the tuning fork through a digital lock-in amplifier action in the computer.

The PZT scanner can perform feedback to adjust the gap between the sample and the probe to several nanometers through digital PID control based on noise-removed information (Tip-sample distance control).

The digitized shear force atomic force microscope (100) replaces the existing function generator, lock-in amplifier, and PID with a computer and DAQ, while achieving sufficient precision to be used in shear force atomic force microscopy (AFM).

The digitized shear force atomic force microscope (100) generates a sinusoidal virtual waveform on a computer in order to resonate and vibrate the tuning fork.

The digitized shear force atomic force microscope 100 can change the virtual waveform into an electrical signal using DAQ and transmit it to the tuning fork, so that the tuning fork is in a resonant vibration state at the same frequency as the frequency of the electrical signal.

The digitized shear force atomic force microscope 100 can amplify the voltage information of the resonance vibrating tuning fork through a preamplifier.

The digitized shear force atomic force microscope 100 receives amplified voltage information from a computer through DAQ.

The computer creates virtual waves in the form of sine and cosine according to the sample rate recognized by the DAQ, and is multiplied by the incoming signal (amplified voltage information) to act as a digital lock-in amplifier.

The digitized shear force atomic force microscope 100 can resonate and vibrate a tuning fork up to about 400 kHz through a digital function generator and a digital lock-in amplifier and recognize the tuning fork signal.

Through this, it is possible to implement a digitally operated shear force atomic force microscope according to the present invention.

Below, the operation of the digitized shear force atomic force microscope 100 according to the present invention will be described.

The digitized shear force atomic force microscope 100 outputs a digital sine wave at about 30khz, which is the resonance frequency of the tuning fork with the probe attached, and causes the tuning fork to resonate and vibrate.

The digitized shear force atomic force microscope 100 amplifies the electrical signal (voltage information) collected from the tuning fork through DAQ by a preamplifier, and reads the amplified electrical signal with a computer.

The digitized shear force atomic force microscope 100 filters the electrical signal recognized by the computer through the action of a digital lock-in amplifier and obtains information between the probe and the sample.

The digitized shear force atomic force microscope 100 adjusts the distance between the probe and the sample by adjusting the PZT, which adjusts the position of the sample, based on the information obtained between the probe and the sample.

The gap between the probe and the sample can be adjusted in nanometers, and the gap error can be, for example, about 1.6 nm.

Atomic force microscopy is essential in research on low-dimensional quantum materials such as 2D semiconductors and 0D quantum dots.

However, these atomic force microscopes include a large number of expensive equipment, which poses an economic burden.

In the case of the digital shear force atomic force microscope according to the present invention, the function generator and lock-in amplifier are all replaced by a computer and DAQ, so economic and spatial benefits can be large.

In addition, the economical shear force atomic force microscope of the present invention can be easily used in other research, and is expected to be of great help in quantum materials research.

The digitized shear force atomic force microscope 100 of the present invention is basically designed to obtain hyperspectral images.

Figure 3 is a gap dependence and time series, Figure 3(a) is a gap dependence showing feedback stability, and Figure 3(b) is a time series showing the stability that can maintain TERS.

Figure 3(a) is a graph of gap dependence, which is a TERS Raman shift graph when the distance between the sample and the tip exceeds 10 nm, and a TERS Raman shift graph when the distance between the sample and the tip is 4 nm to 2 nm.

As shown in FIG. 3(a), it can be seen from the digitized shear force atomic force microscope 100 that the closer the distance between tips is to 2 nm, the greater the intensity peak value is amplified.

Figure 3(b) is a time series, showing the phenomenon of TERS lasting for 30 seconds.

As shown in FIG. 3(b), it can be seen from the digitized shear force atomic force microscope 100 that TERS is maintained constant in the entire Raman shift region.

Looking at Figure 3, in the case of TERS, it is sensitive to the gap between the sample and the tip, and the phenomenon that is adjusted according to the distance from the measured gap shows stable feedback.

The time series also shows evidence that TERS can be obtained stably.

Figure 4 is a diagram showing an example of TERS.

Figure 4 is an example of TERS, which is being carried out in a conventional manner and shows the process of obtaining a TERS image by adjusting the gap between the sample and the tip.

As shown in FIG. 4, the digitized shear force atomic force microscope 100 can excite a digital sine wave E and obtain TERS/TEPL from a tuning fork to which an Au tip is attached. At this time, the Au Tip is 3D tip positioned with respect to the sample.

The DAQ of the present invention can serve to give or receive voltage, and the computer can perform function generating and lock-in amplifier digitally using code.

Figure 5 is a diagram to explain how digital lock-in works.

The digital lock-in amplifier can demodulate the AC voltage of the tuning fork received from the DAQ inside the code by creating and multiplying the sine wave and cosine wave in an array format at the same sampling rate as the signal received inside the computer code.

Afterwards, the Digital Lock-in Amplifier takes the average of the array after filtering it with a digital low-pass filter, squares it, adds the two, and takes the square root, resulting in the amplitude of the original signal, or exactly 1/2 of the amplitude of the desired signal. It comes out in DC.

In Figure 5, the digitized shear force atomic force microscope 100 creates a sine wave and a cosine wave from the signal collected from the tuning fork, filters each of them with Low-Pass, and then averages (mean) / square (X ² ) / addition. By sequentially performing (+)/square root (√), the digital lock-in amplifier function can be operated.

The digitized shear force atomic force microscope (100) of the present invention can implement a function generator, lock-in amplifier, and PID control using only digital methods. At this time, the function generator can use a method of creating a digital sine wave on a computer and sending it as a voltage to the DAQ. The lock-in amplifier can receive the electrical signal from the tuning fork directly through the DAQ and perform digital lock-in processing on the computer. Computers can implement PID control.

Additionally, the digitized shear force atomic force microscope 100 can enable adjustment of the distance from the sample for each tuning fork/probe with different resonance frequencies.

The pointed probe attached to the tuning fork may contain silicon, gold, or tungsten.

Hereinafter, in FIG. 6, the work flow of the digitized shear force atomic force microscope 100 according to embodiments of the present invention will be described in detail.

Figure 6 is a flowchart showing a method of operating a digitized shear force atomic force microscope according to an embodiment of the present invention.

The operating method of the digitized shear force atomic force microscope according to this embodiment can be performed by the digitized shear force atomic force microscope 100.

First, a digital sine wave is output from the DAQ of the digitized shear force atomic force microscope (100) and excited with a tuning fork (610). Step 610 may be a process in which a sine-shaped digital wave is oscillated by a DAQ to a tuning fork, and a probe mounted on the tuning fork detects a sample as an object.

The tuning fork is a device that outputs a waveform of a certain frequency. As it is excited and resonates with the input digital sine wave, a shear force depending on the distance between the samples is applied, outputting a sine wave of different amplitude depending on the distance between the sample and the tip. This allows you to know the height information of the sample, and through this, you can detect the sample.

In the output of a digital sine wave, the DAQ can convert a virtual waveform created by a program in the computer into an electric wave of a frequency that causes the tuning fork to enter a resonance vibration state and output it as the digital sine wave. In other words, DAQ can drive and output a virtual sine wave produced by programming at a specified frequency. At this time, the frequency at which the virtual waveform is driven may be the frequency that causes the tuning fork to enter a resonance vibration state, that is, the same frequency as the natural frequency of the tuning fork itself.

Additionally, in the DAQ of the digitized shear force atomic force microscope (100), the electrical signal from the tuning fork is measured (620). Step 620 may be a process of receiving and measuring the electrical signal by DAQ when a sample is detected at the tuning fork in a resonance vibration state by a digital sine wave and the electrical signal changes.

Subsequently, in the computer of the digitized shear force atomic force microscope 100, noise different from the reference frequency is removed from the measured electrical signal through a digital lock-in amplifier (630). Step 630 may be a process of filtering noise by removing frequency regions that deviate from a set standard from electrical signals collected through DAQ by a computer.

Here, the reference frequency can be determined by the frequency of the digital sine wave output from the DAQ and excited with a tuning fork.

Depending on the embodiment, the digitized shear force atomic force microscope 100 may obtain more accurate height information of the sample by amplifying the electrical signal collected from the tuning fork.

To this end, the electrical signal input from the tuning fork can be amplified in the preamplifier of the digitized shear force atomic force microscope 100 to enable measurement in the DAQ. Through this, the preamplifier can amplify low-level electrical signals, making noise removal easier.

In addition, as the digital lock-in amplifier function, the computer can multiply the amplified electrical signal and a sine-shaped and cosine-shaped virtual wave created according to the sample rate recognized by the DAQ.

The computer demodulates the height information of the tuning fork received from the DAQ (110) inside the computer code by creating and multiplying the sine wave and cosine wave in an array format at the same sample rate as the signal received inside the computer code, and produces the digital lock-in amplifier. It can perform a refire action.

Additionally, the computer can adjust the gap between the sample and the probe of the tuning fork through digital PID control based on the electrical signal from which the noise has been removed. In other words, the computer removes noise different from the reference frequency through the digital lock-in amplifier function, and provides feedback to adjust the gap between the sample and the probe to several nanometers through digital PID control based on the noise-removed electrical signal. You can.

At this time, the probe of the tuning fork includes at least one of silicon, gold, and tungsten, thereby improving detection precision.

According to one embodiment of the present invention, the function generator and lock-in amplifier are replaced with a computer, digitizing the existing analog signal processing method, while maintaining a level of precision that can be used in a shear force atomic force microscope (AFM). It is possible to provide a digitized shear force atomic force microscope and a method of operation, which provides a digitized shear force atomic force microscope and a method of operation.

Additionally, according to an embodiment of the present invention, in a shear force atomic force microscope (AFM), the analog function generator, analog lock-in amplifier, and analog PID can be replaced with a computer and processed digitally.

In addition, according to an embodiment of the present invention, Tip-enhanced Raman Spectroscopy (TERS) measurement, which can also be performed in analog, can be performed through a sufficiently stable shear force atomic force microscope. This TERS measurement is a near-field measurement that can determine the optical properties of a material.

The method according to the embodiment may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer-readable medium may include program instructions, data files, data structures, etc., singly or in combination. Program instructions recorded on the medium may be specially designed and configured for the embodiment or may be known and available to those skilled in the art of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as CD-ROMs and DVDs, and magnetic media such as floptical disks. -Includes optical media (magneto-optical media) and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, etc. Examples of program instructions include machine language code, such as that produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter, etc. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the embodiments, and vice versa.

Software may include a computer program, code, instructions, or a combination of one or more of these, which may configure a processing unit to operate as desired, or may be processed independently or collectively. You can command the device. Software and/or data may be used on any type of machine, component, physical device, virtual equipment, computer storage medium or device to be interpreted by or to provide instructions or data to a processing device. , or may be permanently or temporarily embodied in a transmitted signal wave. Software may be distributed over networked computer systems and thus stored or executed in a distributed manner. Software and data may be stored on one or more computer-readable recording media.

Although the embodiments have been described with limited drawings as described above, those skilled in the art can apply various technical modifications and variations based on the above. For example, the described techniques are performed in a different order than the described method, and/or components of the described system, structure, device, circuit, etc. are combined or combined in a different form than the described method, or other components are used. Alternatively, appropriate results may be achieved even if substituted or substituted by an equivalent.

Therefore, other implementations, other embodiments, and equivalents of the claims also fall within the scope of the following claims.

100: Digitized shear force atomic force microscope
110:DAQ
120: computer
130: preamplifier
140: tuning fork

Claims (13)

The virtual waveform created by the computer program is converted into an electric wave at a frequency that causes the tuning fork to be in a resonance vibration state, output as a digital sine wave, excited by the tuning fork, and the height information of the sample is detected. DAQ (Data AcQuisition), which measures electrical signals; and
A computer that removes noise different from the reference frequency from the measured electrical signal through a digital lock-in amplifier.
Including,
The tuning fork is,
Detecting height information of the sample by outputting sine waves of different amplitudes depending on the distance between the samples using the shear force that acts as it resonates with the digital sine wave that is excited and input.
Digitized shear force atomic force microscopy. delete According to paragraph 1,
The digitized shear force atomic force microscope,
A preamplifier that amplifies the electrical signal input from the tuning fork and enables measurement in the DAQ.
Digitized shear force atomic force microscopy further comprising. According to paragraph 3,
The computer is,
As the digital lock-in amplifier operation, the amplified electrical signal is multiplied by a virtual wave in the form of a sine and a cosine created according to the sample rate recognized by the DAQ.
Digitized shear force atomic force microscopy. According to paragraph 1,
The computer is,
Based on the electrical signal from which the noise has been removed, the gap between the sample and the probe of the tuning fork is adjusted through digital PID control.
Digitized shear force atomic force microscopy. According to clause 5,
The probe of the tuning fork is,
Containing at least one of silicon, gold, and tungsten
Digitized shear force atomic force microscopy. In DAQ, a virtual waveform created by a computer program is converted into an electric wave at a frequency that causes the tuning fork to be in a resonance vibration state, output as a digital sine wave, and excited by the tuning fork;
Detecting height information of the sample by outputting sine waves of different amplitudes according to the distance between samples using a shear force that acts as the tuning fork resonates with the digital sine wave that is excited and input;
In the DAQ, measuring an electrical signal from the tuning fork that detects height information of the sample; and
In a computer, removing noise different from the reference frequency from the measured electrical signal through a digital lock-in amplifier operation.
Method of operation of a digitized shear force atomic force microscope including. delete In clause 7,
In the preamplifier, amplifying the electrical signal input from the tuning fork to enable measurement in the DAQ.
A method of operating a digitized shear force atomic force microscope further comprising: According to clause 9,
In the computer, as the digital lock-in amplifier operation, multiplying the amplified electrical signal by a virtual wave in the form of a sine and a cosine created according to the sample rate recognized by the DAQ.
A method of operating a digitized shear force atomic force microscope further comprising: In clause 7,
Adjusting the gap between the sample and the probe of the tuning fork through digital PID control, in the computer, based on the electrical signal from which the noise has been removed.
A method of operating a digitized shear force atomic force microscope further comprising: According to clause 11,
The probe of the tuning fork is,
Containing at least one of silicon, gold, and tungsten
How a digitized shear force atomic force microscope works. A computer-readable recording medium recording a program for executing the method of any one of claims 7, 9 to 12.

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