A Review on Advanced AFM and SKPFM Data Analytics for Quantitative Nanoscale Corrosion Characterization

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper is technically sound and can be accepted after enhancing the emerging techniques section with a few recent references. The section can be strengthened by adding specific recent references of correlative AFM-Raman or AFM-TEM work.

Also, including a comparative summary table of analytical techniques such as PSD and Gaussian, deconvolution (with advantages and limitations) would further enhance readability.

Author Response

Reviewer  1

Comments and Suggestions for Authors

1. The paper is technically sound and can be accepted after enhancing the emerging techniques section with a few recent references. The section can be strengthened by adding specific recent references of correlative AFM-Raman or AFM-TEM work.

Response: We thank the reviewer for this helpful suggestion. A new paragraph on recent correlative AFM–Raman and AFM–TEM developments has been added to the Emerging Techniques section, supported by three recent studies.

2. Also, including a comparative summary table of analytical techniques such as PSD and Gaussian, deconvolution (with advantages and limitations) would further enhance readability.

Response: We thank the reviewer for this helpful suggestion. A comparative summary table, table 1 (new one) has been added to Section 2 to present the main AFM/SKPFM analytical techniques (line-profile, PSD, histogram/Gaussian, and deconvolution) together with their typical inputs, outputs, advantages, and limitations.

Table 1. Summary of representative studies employing AFM and complementary techniques to investigate surface properties, structural features, and related corrosion performance across different material systems. A final checklist row summarizes key experimental parameters and practical considerations for AFM–SKPFM corrosion measurements.

Technique	Purpose in Corrosion Analysis	Typical Inputs & Outputs	Advantages	Limitations
Line Profile Analysis	Extracts 1D height variations to measure pit depth, trenching, and localized attack zones.	Input: AFM topography line scan; Output: depth, width, slope of features.	Simple and direct; useful for visualizing localized corrosion features.	Limited to 1D; cannot capture lateral heterogeneity or spatial distribution of corrosion features.
Power Spectral Density (PSD)	Decomposes surface roughness into spatial frequency components to identify dominant corrosion scales.	Input: 2D AFM topography; Output: PSD plot, correlation length, roughness exponent.	Scale-invariant; robust against noise; enables multiscale roughness quantification.	Assumes stationarity; sensitive to tip convolution and scan size limits.
Multimodal Histogram Analysis	Statistically separates surface features (e.g., oxides, substrate, corrosion products) based on height or potential distributions.	Input: AFM/SKPFM data; Output: histogram with multiple Gaussian fits.	Quantifies phase fractions; identifies emergent corrosion products.	Assumes Gaussian distributions; lacks spatial context; sensitive to bin size and overfitting.
Gaussian Fitting	Fits statistical distributions of surface height or potential to identify distinct populations.	Input: histogram of AFM/SKPFM data; Output: mean, standard deviation, amplitude of each Gaussian component.	Enables quantitative comparison of surface phases; supports histogram analysis.	May not capture non-Gaussian features; prone to overfitting if too many components used.
Deconvolution	Corrects tip-induced distortions in AFM/SKPFM images to recover true surface morphology.	Input: raw AFM image + tip model or blind estimation; Output: corrected topography.	Improves spatial resolution; reveals hidden nanoscale corrosion features.	Sensitive to noise and PSF accuracy; may introduce artifacts if over-applied.

Reviewer 2 Report

Comments and Suggestions for Authors

The authors in their review entitled “A Review on Advanced AFM and SKPFM Data Analytics for Quantitative Nanoscale Corrosion Characterization” focuses on the use of Atomic Force Microscopy (AFM) integrated with Scanning Kelvin Probe Force Microscopy (SKPFM) and advanced data analysis techniques (PSD, multimodal Gaussian histograms, statistical roughness quantification) for metal corrosion studies. This is a well-organized review that provides representative studies employing the above-mentioned methods in various metal alloy|electrolyte systems and merits publication. Few minor points listed in the following should be considered before a possible publication. 

Comments

1. The authors mention very often in this review that the advanced AFM and SKPFM methods integrated with traditional electrochemical methods enable quantitative and mechanistic insights at the micro/nanoscale of various corrosion phenomena. However, they provide a rather qualitative description of the information gained for the representative examples presented. It would be very helpful if some of the representative examples were selected to be further analysed to show how the analysis of AFM and SKPFM data integrated with complementary traditional techniques led to a quantitative nanoscale corrosion characterization.
2. Section 4. Please cite appropriate references especially in lines 597 – 599 where studies on specific systems are reported (e.g. after “…including aluminum-copper joints”, “NiAl bronze” “dissimilar aluminum alloy welds (AA5083/AA7023)”, “Ti-6Al-4V”, “duplex stainless steels”, “superhydrophobic coat”.
3. Figure 6: Electroless nickel coatings are mentioned in the figure caption and in Fig. 6b (Releative content -Volta potential) as NP whereas in the text (line 445) and Fig. 6b (AFM images) as NiP.  
4. Figure 7: Please mention in the figure caption that the illustrated experimental results are referred to AA5083.

Author Response

Reviewer 2

The authors in their review entitled “A Review on Advanced AFM and SKPFM Data Analytics for Quantitative Nanoscale Corrosion Characterization” focuses on the use of Atomic Force Microscopy (AFM) integrated with Scanning Kelvin Probe Force Microscopy (SKPFM) and advanced data analysis techniques (PSD, multimodal Gaussian histograms, statistical roughness quantification) for metal corrosion studies. This is a well-organized review that provides representative studies employing the above-mentioned methods in various metal alloy|electrolyte systems and merits publication. Few minor points listed in the following should be considered before a possible publication. 

Comments

1. The authors mention very often in this review that the advanced AFM and SKPFM methods integrated with traditional electrochemical methods enable quantitative and mechanistic insights at the micro/nanoscale of various corrosion phenomena. However, they provide a rather qualitative description of the information gained for the representative examples presented. It would be very helpful if some of the representative examples were selected to be further analysed to show how the analysis of AFM and SKPFM data integrated with complementary traditional techniques led to a quantitative nanoscale corrosion characterization.

Thank you for this valuable suggestion. We have expanded Section 3.1 to include two detailed case studies that demonstrate quantitative integration of AFM/SKPFM with complementary techniques:

• Figure 2a (Al/Cu joint): SKPFM mapping combined with histogram analysis and PSD evaluation quantified Volta potential differences at intermetallic boundaries, confirming localized corrosion initiation at these sites (Ref).
• Figure 2b (AA5083/AA7023 weld): PSD and Gaussian fitting were applied to AFM topography and SKPFM data to correlate surface roughness evolution with electrochemical data, providing a quantitative link between microstructural heterogeneity and corrosion susceptibility.

Similar quantitative analyses have also been incorporated for other systems discussed in the Section 3.2 that the manuscript now includes representative examples where advanced AFM/SKPFM data processing yields measurable parameters rather than purely qualitative descriptions.

 

1. Section 4. Please cite appropriate references especially in lines 597 – 599 where studies on specific systems are reported (e.g. after “…including aluminum-copper joints”, “NiAl bronze” “dissimilar aluminum alloy welds (AA5083/AA7023)”, “Ti-6Al-4V”, “duplex stainless steels”, “superhydrophobic coat”.

Response: We thank the reviewer for this helpful suggestion. Relevant citations have now been added in Section 4 to support the examples mentioned, including the corresponding references.

1. Figure 6: Electroless nickel coatings are mentioned in the figure caption and in Fig. 6b (Relative content -Volta potential) as NP whereas in the text (line 445) and Fig. 6b (AFM images) as NiP.  

Response: We thank the reviewer for the observation. The “NP-a, NP-b, and NP-c” labels are preserved as they follow the original study’s nomenclature. To clarify this, the figure caption has been revised to specify that NP-a, NP-b, and NP-c correspond to electroless NiP coatings with phosphorus contents of 13.2 wt%, 12.9 wt%, and 8.3 wt%, respectively.

1. Figure 7: Please mention in the figure caption that the illustrated experimental results are referred to AA5083.

Response: We thank the reviewer for this helpful note. The caption of Figure 7 has been revised to specify that the presented experimental results correspond to sensitized AA5083 aluminum alloy.

Reviewer 3 Report

Comments and Suggestions for Authors

Dear Authors and Editor,

In review I received a manuscript – a comprehensive tutorial-style review of AFM and SKPFM for localized corrosion, highlighting data treatment (histogram/PSD) and case studies on Al-, Ti-, steel-, and CoCrMo-based systems. The emphasis is on quantitative image analysis (histograms, PSD) and mechanistic links to local electrochemistry. It adds value by collating practical cautions (calibration, humidity, tip convolution) with examples where microstructure–Volta potential correlates with initiation sites. The manuscript is timely and generally well-structured, with many instructive figures (e.g., the AFM/SKPFM workflows and PSD equations) and a broad reference list. The writing is mostly clear, though some terminology and style need tightening, and a few references/claims should be verified or completed.

Several items require revision: acronyms/terminology consistency (AM-KPFM), minor figure/caption and citation-order issues, polishing of English/typography, and reference checks/completions, summarized below:

(0) For the editor – I would appreciate if in review I received a “clean” version of the manuscript, without the active “comments”.

Major comments:

(1) Throughout “amplitude-modulated SKPFM” is labeled “ASPFM.” The established acronyms are AM-KPFM (amplitude-modulation) and FM-KPFM (frequency-modulation); so I would suggest to replace “ASPFM” with AM-KPFM everywhere and take care that the first definition of KPFM/SKPFM clarifies the measured Volta potential is relative (offset arbitrary), not a direct corrosion potential (you already note relativity).

(2) You present 1D/2D PSD relations (Eqs. 2–3; PSD vs. spatial frequency). Please specify explicitly whether the reported PSDs are 1D line-based or 2D surface PSDs and state the units used in all plots (e.g., nm^2·µm for 1D PSD, nm^4 for 2D PSD; or V^2 equivalents for SKPFM). Add a one-line note on windowing, de-trending, and binning, since these choices strongly affect slope and intercept and are essential for reproducibility.

(3) Where you report large Volta potential differences (e.g., AA5083 vs. AA7023), make sure that the numerical ranges align with the original studies and specify the humidity/media during SKPFM. Your cited dissimilar-FSW studies indeed demonstrate the microstructure-Volta-initiation linkage and histogram/PSD correlations (e.g., Davoodi et al., Corros. Sci. 2016)

(4) Your CoCrMo discussion match recent reports on albumin adsorption lowering surface potential relative to native oxides and increases space-charge capacitance; localized attack can occur at the protein/substrate interface (JES 2022). Your 2024 ACS AMI citations for Mg (WE43) and apoferritin–MONP interactions look ok; please add a sentence distinguishing short-term BSA effects (minutes–hours) from longer-term protein–ion complexation that can evolve surface chemistry and apparent ESP.

(5) Phrases suggesting prediction of corrosion rate from static AFM/SKPFM maps should be softened. Consider reframing to “probabilistic risk indicators of initiation susceptibility,” unless coupled with time-lapse (e.g., in-situ SKPFM) or corrosion-rate sensors data streams. You can introduce ER-based multi-droplet monitoring as a complementary kinetic tool.

(6) MDPI journals typically require a Data Availability Statement even for reviews; please add “Not applicable” or links to any processed datasets or code (e.g., PSD scripts). Make sure Conflicts of Interest and Author Contributions sections follow journal style.

Minor comments:

(6) There’s an editorial note asking to cite figures in numerical order. Please check that each figure (and each subpanel a/b/c) is first cited sequentially in the main text and that all panels referred to in captions are actually discussed. If any figures are illustrative only, say so in the caption.

(7) Make sure all scale bars, color-bar units (mV for SKPFM, nm for AFM), and acquisition parameters (lift height, amplitude setpoint, scan rate, humidity/ambient conditions) are stated in captions. For workflow figures, adding a single “calibration box” (work function reference, tip condition checks) would be helpful.

(8) Update inconsistent hyphenation (“time-lapse” vs “time lapse”), and first capita letter (e.g. Kelvin probe force microscopy).

(9) Table 1 and the AFM/SKPFM comparison are useful, but consider adding a compact checklist row (humidity control, lift-mode parameters, tip bias calibration, artifact checks) with pointers to sections where each is discussed.

 

references:

(10) Check citation; e.g. Insights into Galvanic Corrosion Behavior of Ti–Cu Dissimilar Joint…”=> add full journal details (Materials 2018, 11, 1820) and DOI (10.3390/ma11101820). (Now you only show “11:”.). For any 2025 “in press” items, ensure final page/article numbers are present before production (Applied Surface Science 689 and Corrosion Science 251 are live)

 

language:

(11) Replace “AFM/SKPFM imaging can predict corrosion rate” with “can indicate susceptibility and likely initiation sites”; reserve “rate” for kinetic measurements or coupled tests. (You can cite ER-sensor or time-lapse SKPFM examples for kinetics.)

(12) When discussing tip-bias and lift-height, add typical values (e.g., bias range 1–2 V, lift 50–100 nm) and caution about capacitive crosstalk at small lift heights.

(13) Unify symbols: use ϕ_V (Volta potential) consistently; define Δϕ_V.

(14) Ensure all abbreviations are defined at first use (PSD, SVET, AC-DC, ER).

(15) Check hyphenation and en-dashes: “Mott–Schottky,” “time-lapse,” “near-nanocrystalline.”

(16) Consider a one-page “Practical checklist for AM-KPFM corrosion studies” at the end (environment control, referencing, drift compensation, humidity, lift-height, artifact tests).

(17) Add a short paragraph in the conclusions emphasizing limits (offset ambiguity; environment sensitivity; protein specificity) and best-practice recommendations.

Although this manuscript draft seems like a potentially useful tutorial-style review article, quite a lot has to be updated before it is suitable for publication. Consider (as for review-type of paper) that you expand your references beyond personal ones, currently ~30 out of 51 are from the authors itself (or both). If this is only a tutorial- or methods-type of paper, has to be declared in advance.

Comments on the Quality of English Language

Not having very strong issues with the English, but the manuscript would need some proofreading. 

Author Response

Reviewer 3

Comments and Suggestions for Authors

Dear Authors and Editor,

In review I received a manuscript – a comprehensive tutorial-style review of AFM and SKPFM for localized corrosion, highlighting data treatment (histogram/PSD) and case studies on Al-, Ti-, steel-, and CoCrMo-based systems. The emphasis is on quantitative image analysis (histograms, PSD) and mechanistic links to local electrochemistry. It adds value by collating practical cautions (calibration, humidity, tip convolution) with examples where microstructure–Volta potential correlates with initiation sites. The manuscript is timely and generally well-structured, with many instructive figures (e.g., the AFM/SKPFM workflows and PSD equations) and a broad reference list. The writing is mostly clear, though some terminology and style need tightening, and a few references/claims should be verified or completed.

Several items require revision: acronyms/terminology consistency (AM-KPFM), minor figure/caption and citation-order issues, polishing of English/typography, and reference checks/completions, summarized below:

(0) For the editor – I would appreciate if in review I received a “clean” version of the manuscript, without the active “comments”.

Major comments:

(1) Throughout “amplitude-modulated SKPFM” is labeled “ASPFM.” The established acronyms are AM-KPFM (amplitude-modulation) and FM-KPFM (frequency-modulation); so I would suggest to replace “ASPFM” with AM-KPFM everywhere and take care that the first definition of KPFM/SKPFM clarifies the measured Volta potential is relative (offset arbitrary), not a direct corrosion potential (you already note relativity).

Response: We thank the reviewer for this valuable observation. The acronym “ASPFM” has been replaced throughout the manuscript with the correct terminology “AM-KPFM (Amplitude-Modulation Kelvin Probe Force Microscopy)” to align with established conventions. Additionally, a clarifying sentence has been added after the first mention of SKPFM (Section 1) to emphasize that the Volta potentials measured by SKPFM are relative values.

(2) You present 1D/2D PSD relations (Eqs. 2–3; PSD vs. spatial frequency). Please specify explicitly whether the reported PSDs are 1D line-based or 2D surface PSDs and state the units used in all plots (e.g., nm^2·µm for 1D PSD, nm^4 for 2D PSD; or V^2 equivalents for SKPFM). Add a one-line note on windowing, de-trending, and binning, since these choices strongly affect slope and intercept and are essential for reproducibility.

Response: We thank the reviewer for this constructive comment. A clarifying paragraph has been added at the end of Section 2.1 to specify that all PSD analyses in this review are two-dimensional (2D), derived from the full AFM or SKPFM image data rather than line profiles. The corresponding units are now explicitly indicated as nm⁴ for topography-based PSDs and V²·µm² for SKPFM-based PSDs. In addition, a brief note on preprocessing steps—de-trending, windowing, and binning—has been included to highlight their impact on PSD reproducibility and quantitative comparison.

(3) Where you report large Volta potential differences (e.g., AA5083 vs. AA7023), make sure that the numerical ranges align with the original studies and specify the humidity/media during SKPFM. Your cited dissimilar-FSW studies indeed demonstrate the microstructure-Volta-initiation linkage and histogram/PSD correlations (e.g., Davoodi et al., Corros. Sci. 2016)

Response: We thank the reviewer for this important remark. The Volta potential differences for the AA5083/AA7023 friction-stir weld have been confirmed to match the data reported. A clarifying sentence has been added in Section 3.1 specifying that these SKPFM measurements were performed in air at 35 ± 2 % relative humidity and room temperature, with the potentials interpreted as relative values referenced to the probe work function.

(4) Your CoCrMo discussion match recent reports on albumin adsorption lowering surface potential relative to native oxides and increases space-charge capacitance; localized attack can occur at the protein/substrate interface (JES 2022). Your 2024 ACS AMI citations for Mg (WE43) and apoferritin–MONP interactions look ok; please add a sentence distinguishing short-term BSA effects (minutes–hours) from longer-term protein–ion complexation that can evolve surface chemistry and apparent ESP.

Response: We thank the reviewer for this insightful comment. A clarifying sentence has been added in Section 3.2 to differentiate between short-term albumin adsorption effects (minutes to hours) that modify surface potential and passive film integrity, and longer-term protein–ion complexation processes that evolve surface chemistry and the apparent electrostatic surface potential.

(5) Phrases suggesting prediction of corrosion rate from static AFM/SKPFM maps should be softened. Consider reframing to “probabilistic risk indicators of initiation susceptibility,” unless coupled with time-lapse (e.g., in-situ SKPFM) or corrosion-rate sensors data streams. You can introduce ER-based multi-droplet monitoring as a complementary kinetic tool.

Response: We thank the reviewer for this valuable comment. All instances implying direct corrosion rate prediction by AFM/SKPFM have been revised throughout the manuscript (Sections 3.4, 4, Abstract, and Conclusions). The text now emphasizes that AFM and SKPFM provide probabilistic indicators of corrosion initiation susceptibility rather than quantitative corrosion-rate predictions. In addition, we note that accurate kinetic evaluation requires complementary time-lapse or in-situ techniques such as SKPFM under controlled environments or electrical-resistance (ER)–based multi-droplet monitoring.

(6) MDPI journals typically require a Data Availability Statement even for reviews; please add “Not applicable” or links to any processed datasets or code (e.g., PSD scripts). Make sure Conflicts of Interest and Author Contributions sections follow journal style.

Response: We thank the reviewer for this editorial reminder. A Data Availability Statement has been added before the References section, stating that no new data were created or analyzed in this study. The formatting of the Author Contributions and Conflicts of Interest sections has also been updated to align with MDPI journal style.

Minor comments:

(6) There’s an editorial note asking to cite figures in numerical order. Please check that each figure (and each subpanel a/b/c) is first cited sequentially in the main text and that all panels referred to in captions are actually discussed. If any figures are illustrative only, say so in the caption.

Response: We thank the reviewer for this editorial suggestion. The manuscript has been reviewed to ensure that all figures are cited sequentially in the main text and that each figure is also discussed in the corresponding section.

(7) Make sure all scale bars, color-bar units (mV for SKPFM, nm for AFM), and acquisition parameters (lift height, amplitude setpoint, scan rate, humidity/ambient conditions) are stated in captions. For workflow figures, adding a single “calibration box” (work function reference, tip condition checks) would be helpful.

Response: We thank the reviewer for this helpful suggestion. All figure captions have been updated to include key AFM/SKPFM parameters such as tip type, lift height, humidity or temperature, and scan rate. Notes on probe calibration and measurement conditions were also added where relevant to enhance clarity and reproducibility.

(8) Update inconsistent hyphenation (“time-lapse” vs “time lapse”), and first capita letter (e.g. Kelvin probe force microscopy).

Response: We thank the reviewer for noting these important stylistic inconsistencies. The manuscript has been carefully reviewed and revised to ensure uniform hyphenation and capitalization throughout.

(9) Table 1 and the AFM/SKPFM comparison are useful, but consider adding a compact checklist row (humidity control, lift-mode parameters, tip bias calibration, artifact checks) with pointers to sections where each is discussed.

Response: A compact checklist row has been added to Table 1, summarizing essential experimental parameters—humidity control, lift-mode height, tip-bias calibration, and artifact verification—with references to Sections 2.3 and 4 where these are discussed in detail.

 

references:

(10) Check citation; e.g. Insights into Galvanic Corrosion Behavior of Ti–Cu Dissimilar Joint…”=> add full journal details (Materials 2018, 11, 1820) and DOI (10.3390/ma11101820). (Now you only show “11:”.). For any 2025 “in press” items, ensure final page/article numbers are present before production (Applied Surface Science 689 and Corrosion Science 251 are live)

Response: We thank the reviewer for the careful attention to reference completeness and formatting. The entire reference list has been thoroughly reviewed and updated to ensure accuracy and conformity with MDPI citation style. All entries now include complete bibliographic details—journal name, volume, page or article number, and DOI where available.

 

language:

(11) Replace “AFM/SKPFM imaging can predict corrosion rate” with “can indicate susceptibility and likely initiation sites”; reserve “rate” for kinetic measurements or coupled tests. (You can cite ER-sensor or time-lapse SKPFM examples for kinetics.)

Response: We thank the reviewer for this valuable note. The relevant sentences have been revised to use scientifically precise wording consistent with kinetic terminology and corrosion characterization practices.

(12) When discussing tip-bias and lift-height, add typical values (e.g., bias range 1–2 V, lift 50–100 nm) and caution about capacitive crosstalk at small lift heights.

Response: We thank the reviewer for this constructive suggestion. Typical SKPFM operating parameters have now been specified in Section 2.3, including a bias range of 1–2 V and a lift height of 50–100 nm. A cautionary note regarding possible capacitive crosstalk at smaller lift heights has also been added to emphasize optimal parameter selection and measurement reliability.

(13) Unify symbols: use ϕ_V (Volta potential) consistently; define Δϕ_V.

Response: We appreciate the reviewer’s observation. The manuscript does not employ symbolic notation for the Volta potential, as all references to it are expressed in full text form (e.g., Volta potential, Volta potential difference). For clarity and consistency, this convention has been retained throughout the paper.

(14) Ensure all abbreviations are defined at first use (PSD, SVET, AC-DC, ER).

Response: We thank the reviewer for this helpful remark. The entire manuscript has been carefully reviewed to ensure that all abbreviations are clearly defined at their first appearance and used consistently throughout the text.

 

(15) Check hyphenation and en-dashes: “Mott–Schottky,” “time-lapse,” “near-nanocrystalline.”

Response: We thank the reviewer for pointing this out. Hyphenation and en-dash usage have been carefully reviewed throughout the manuscript.

(16) Consider a one-page “Practical checklist for AM-KPFM corrosion studies” at the end (environment control, referencing, drift compensation, humidity, lift-height, artifact tests).

Response: We thank the reviewer for this valuable suggestion. A concise “Practical Checklist for AM-KPFM Corrosion Studies” has been added at the end of Section 4, summarizing key parameters such as environmental control, humidity, lift height, tip-bias calibration, drift correction, and artifact testing.

(17) Add a short paragraph in the conclusions emphasizing limits (offset ambiguity; environment sensitivity; protein specificity) and best-practice recommendations.

Response: We thank the reviewer for this suggestion. A brief paragraph has been added to the Conclusions highlighting key limitations of AFM/SKPFM and emphasizing best-practice measures to improve data reliability.

Although this manuscript draft seems like a potentially useful tutorial-style review article, quite a lot has to be updated before it is suitable for publication. Consider (as for review-type of paper) that you expand your references beyond personal ones, currently ~30 out of 51 are from the authors itself (or both). If this is only a tutorial- or methods-type of paper, has to be declared in advance.

Response: Thank you for this observation. This manuscript is intended as a special review highlighting the pioneering contributions of Professor Christofer Leygraf and his research team to the field of nanoscale corrosion analysis. The emphasis on their work reflects the historical and scientific significance of these studies, as I was part of this research group during my Ph.D., and this review acknowledges that legacy.

While many references originate from this body of work, we have also incorporated additional relevant studies from other researchers to ensure broader coverage and context. The primary focus remains on the foundational research that shaped advanced AFM and SKPFM methodologies, which is why a substantial portion of the cited literature comes from this group.

 

Comments on the Quality of English Language

Not having very strong issues with the English, but the manuscript would need some proofreading. 

Response: We did it a thorough proofreading. Thanks for the comment.

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

Looks like authors verified all comments.