Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

Dear authors,

The topic addressed is of considerable scientific interest. However, I have identified several fundamental aspects that require significant attention in order to raise the quality of the work to the standard expected for a review article.

The introductory section is insufficient for a review article and requires substantial restructuring. The state of the art is not adequately established, nor is the relevance of the topic in the current context of engine engineering justified. It is recommended that you incorporate the fundamental equations that describe the behavior of each type of engine (e.g., equations for torque, power, energy efficiency, and thermodynamic relationships where applicable).

The manuscript has significant deficiencies in the depth of its technical analysis. Numerous specialized concepts and terms are mentioned superficially without the necessary rigorous explanation. Parameters such as efficiency, power density, form factors, and torque-speed characteristics need to be clearly defined.

The manuscript lacks a structured discussion section, which is a major shortcoming in a review article. The following elements must be included: a detailed evaluation comparing different types of motors based on multiple criteria energy efficiency, power density, manufacturing and operating costs, maintenance, service life, optimal applications, technical limitations, and environmental impact as well as a clear and structured presentation of the advantages and disadvantages of each technology, based on technical evidence and quantitative data. Additionally, you should provide a discussion on technological evolution, emerging developments, and future directions in the field, along with practical guidance on which type of motor is most appropriate for different application scenarios.

The manuscript does not include a conclusions section. Conclusions should summarize the main findings of the review, suggest directions for future research, and offer practical recommendations based on the analysis performed.

Author Response

For reviewer 3

 

Q1: The introductory section is insufficient for a review article and requires substantial restructuring. The state of the art is not adequately established, nor is the relevance of the topic in the current context of engine engineering justified. It is recommended that you incorporate the fundamental equations that describe the behavior of each type of engine (e.g., equations for torque, power, energy efficiency, and thermodynamic relationships where applicable). 

A1: Thank you very much for your valuable advice. I have supplemented the basic equations describing the operating characteristics of various types of engines in the introduction section.

The manuscript is added as follows:

1. Introduction

Piezoelectric motors  feature flexible structural design, compact size, no magnetic interference, high displacement resolution, and large travel range. They hold great application potential in fields requiring precise positioning, such as aerospace, precision optics, and precision machining [1-6]. These motors utilize the inverse piezoelectric effect to convert electrical energy into mechanical energy, which is then transformed into kinetic energy through a series of specialized mechanisms [7}.

Based on their driving methods and operating principles, piezoelectric motors can be categorized into ultrasonic motors and piezoelectric peristaltic motors, with the primary differences lying in the method and structure used for kinetic energy conversion [8-11].

The basic governing equations for piezoelectric motor performance can be expressed as follows:

 

 

 

T is the output torque, F is the tangential frictional driving force, r is the effective radius of the contact surface, μ is the friction coefficient between the stator and rotor (or slider), P is the mechanical power output, ω is the angular velocity, V and I are the  input voltage and current, and η represents the overall energy conversion efficiency.

 

Q2:The manuscript has significant deficiencies in the depth of its technical analysis. Numerous specialized concepts and terms are mentioned superficially without the necessary rigorous explanation. Parameters such as efficiency, power density, form factors, and torque-speed characteristics need to be clearly defined.

A2: Thank you very much for your valuable advice. I have supplemented the fundamental equations for parameters such as efficiency and torque. For piezoelectric motors, except for rotary ultrasonic motors, there are no standardized models available—all are custom-made. As a result, their structural parameters vary significantly, which is why these parameters have not been explained or defined in the manuscript. I hope you can understand this.

Q3: The manuscript lacks a structured discussion section, which is a major shortcoming in a review article. The following elements must be included: a detailed evaluation comparing different types of motors based on multiple criteria energy efficiency, power density, manufacturing and operating costs, maintenance, service life, optimal applications, technical limitations, and environmental impact as well as a clear and structured presentation of the advantages and disadvantages of each technology, based on technical evidence and quantitative data. Additionally, you should provide a discussion on technological evolution, emerging developments, and future directions in the field, along with practical guidance on which type of motor is most appropriate for different application scenarios.

A3: Thank you very much for your valuable advice. I have added a new "Discussion" section, in which I conducted comparative analysis and discussion of different types of motors based on the table.

The manuscript is added as follows:

The numerical parameters summarized in Table 1 provide a quantitative compar-ison of different piezoelectric motor types.

Ultrasonic motors exhibit the highest operating speed (up to several hundred mil-limeters per second) and power density, making them suitable for rapid-response ap-plications such as camera autofocus systems and robotic actuation mechanisms. How-ever, their energy efficiency (20–40%) and positioning stability are often limited by frictional heating and surface wear, which also affect their long-term durability.

Peristaltic piezoelectric motors achieve a balanced performance among stroke range, resolution, and efficiency, while maintaining a relatively simple control mecha-nism. Their moderate operating frequency (1–10 kilohertz) effectively reduces heat generation, and the efficiency of 25–50 percent makes them particularly advantageous for use in aerospace, vacuum, and optical alignment systems where both stability and reliability are critical.

Inertial motors, although structurally simple and capable of achieving extremely fine resolution (less than 10 nanometers), are restricted by their low output force and nonlinear stick–slip motion, which reduce control repeatability and overall energy effi-ciency. Consequently, they are primarily applied in micro-displacement positioning stages and atomic force microscopy (AFM) scanners, where compactness and sub-nanometer precision are required rather than high load capacity.

Overall, the quantitative comparison highlights that ultrasonic motors excel in speed-driven applications, peristaltic piezoelectric motors provide the most effective compromise between efficiency and precision, and inertial motors are preferable for ultra-fine but low-force positioning tasks.

 

Table 1. Performance characteristics of piezoelectric drive motors with different principles in various aspects.

Principle	Ultrasonic motor	Inertial motor	Peristaltic motor
Trip	Large itinerary	Large itinerary	Large itinerary
Running speed	Extremely high （200mm/s）	Medium	Medium（0.5mm/s）
Resolution	100nm	100nm	20nm
Positioning stability	Medium	Low	High
Load	Medium	Low	High
Frequency	High	Medium	Low
Friction	High friction	Frictional	Slight friction
Fever	Fever	Mild fever	No fever
Energy efficiency	Inefficient	Relatively high efficient	High efficient
Structural complexity	Relatively high	Relatively Low	High
Control characteristics	Specific waveform	Specific waveform	Specific timing sequence
Control difficulty	Complex	Easy	Complex
Curve trajectory	Supporting	Forbidden	Supporting

 

Q4：The manuscript does not include a conclusions section. Conclusions should summarize the main findings of the review, suggest directions for future research, and offer practical recommendations based on the analysis performed.

A4：Thank you very much for your valuable advice. The final chapter of the review has been revised to "Summary and Future Development," which includes the content mentioned in the suggestions.

The manuscript is added as follows:

6. Conclusions and Outlook

Compared to traditional motors, piezoelectric motors offer advantages in terms of weight, size, driving torque, and structural design. Different types of piezoelec-tric-driven motors also exhibit varying performance characteristics in aspects such as travel range, speed, precision, and load capacity.

Among them, ultrasonic motors and piezoelectric peristaltic motors are the most widely used, particularly excelling in aerospace applications, making them a current research focus. A key challenge is adapting these motors for operation in vacuum en-vironments, mitigating the effects of temperature variations on performance, and ad-dressing issues related to clamping mechanism materials and structures to prevent cold welding. These aspects require further in-depth research.

 

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This article, presented as a review article, is not, in fact, a review article. It presents a disjointed and subjective description of several drive types or measurements.

1. The article does not present a review methodology. It does not describe what resources were searched to generate an objective set of descriptions, how the databases were searched, what article databases were searched, what patent databases were searched, what search methods were used, how the found materials were analyzed, what statistical analyses were performed on the found resources, etc.
2. In the context of the previous comment, no objective and justified classification was presented, and the operating principle for each class of measurement, drive was not described.
3. The figures are unclear and do not present the operating principles clearly. The authors confuse the descriptions of the operating principles with the actual application of a given drive/measurement type.
4. The limitations of the suggested applications, especially aerospace,  were not analyzed, and no assessment of the drive/measurement was made in the context of these limitations.

5. Trends were not determined, and the development of individual methods was not assessed in the context of technological development/time.
6. The operating descriptions are complicated, and the figures are not at all helpful in understanding these descriptions.
7. The authors primarily use from third-party, proprietary drawings that are irrelevant to the content presented.
8. The final table includes drive classes not described at all in the article.

Author Response

For reviewer 2

 

C1. The article does not present a review methodology. It does not describe what resources were searched to generate an objective set of descriptions, how the databases were searched, what article databases were searched, what patent databases were searched, what search methods were used, how the found materials were analyzed, what statistical analyses were performed on the found resources, etc.

A1: Thank you very much for your valuable advice. I have added an explanation of the review methodology in the first paragraph, which includes content related to databases, search methods, and other relevant aspects.

The manuscript is added as follows:

To ensure objectivity and reproducibility, this study adopted a systematic review methodology. Using the keywords "piezoelectric motor", "ultrasonic motor", and "peristaltic motor", literature was retrieved from databases such as Web of Science and Google Scholar, covering the search period from 1995 to 2025. This study discusses the structures and applications of different types of piezoelectric motors.

C2. In the context of the previous comment, no objective and justified classification was presented, and the operating principle for each class of measurement, drive was not described.

A2: Thank you very much for your valuable advice. We have explained the classification of piezoelectric motors in the introduction section. The subsequent content is elaborated in accordance with this classification, and the first paragraph of each chapter describes the principle of the corresponding type of piezoelectric motor.

C3. The figures are unclear and do not present the operating principles clearly. The authors confuse the descriptions of the operating principles with the actual application of a given drive/measurement type.

A3: Thank you very much for your valuable advice. I have improved the clarity of the images.

C4. The limitations of the suggested applications, especially aerospace,  were not analyzed, and no assessment of the drive/measurement was made in the context of these limitations.

A4: Thank you very much for your valuable advice. I have analyzed the limitations of its application in the aerospace field.

The manuscript is added as follows:

2. Ultrasonic motor

The principle of ultrasonic motors is as follows: by applying a pre-tightening force to the stator and rotor, which form a kinematic pair, the vibration energy generated from electrical energy is directly converted into the driving force of the rotor, thereby ena-bling high-efficiency continuous rotational or linear motion [22-26]. Ultrasonic motors inherently offer advantages such as high torque, fast dynamic response, and immunity to electromagnetic interference [27-31]. This is because their operating mechanism is fundamentally different from that of traditional motors, which obtain speed and torque through electromagnetic effects. Instead, ultrasonic motors apply an alternating voltage at ultrasonic frequencies to piezoelectric ceramics, and through the inverse piezoelectric effect, electrical energy is converted into kinetic and mechanical energy. The emergence of ultrasonic motors has resolved the conflict between small size and high torque in the aerospace field (Figure 1(a) [32]), while their self-locking capability upon power-off makes them highly suitable for high-precision positioning in advanced manufacturing (Figure 1(b) [33]). the performance of the friction materials in ultrasonic motors differs significantly between vacuum environments and ground test conditions, which in turn leads to a decline in the motor's performance. Additionally, Ultrasonic motors enable fast speeds for pointing mechanisms and solar panel deployment. However, they have the disadvantage of low positioning accuracy.  As a result, ultrasonic motor technology holds broad application prospects.

C5. Trends were not determined, and the development of individual methods was not assessed in the context of technological development/time.

A5：Thank you very much for your valuable advice. I have revised the last section to "Conclusions and Trends" and clarified the development trends of piezoelectric motors. The manuscript is added as follows:

6. Conclusions and Trends

Compared with traditional motors, piezoelectric motors have advantages in terms of weight, size, driving torque, and structural design. Piezoelectric motors with differ-ent principles and structures each have their own strengths in terms of travel range, speed, precision, and load capacity. Currently, ultrasonic motors and peristaltic motors have attracted the highest attention and have the widest range of applications.

Ultrasonic motors feature high speed, compact structure, and a wide torque range. However, they have a relatively long steady-state time, which leads to a sharp drop in precision during low-speed operation and ultra-short displacement. To address the nonlinearity issue of ultrasonic motors, designing new motor structures (such as rhombic vibrators) or proposing new control methods (such as instantaneous driving) has become the current mainstream trend. In the aerospace field, the impact of tem-perature on the performance of motor friction materials is also a key research focus.

Peristaltic motors offer large load capacity, high precision, and power-off holding functionality. Nevertheless, their high precision is particularly dependent on high-precision guiding mechanisms. Therefore, the integrated design of peristaltic motors and guiding mechanisms is the current mainstream trend. In the aerospace field, the cold welding issue of motor clamping mechanisms and the weight reduction of the overall motor are also hot topics in current research.

C6. The operating descriptions are complicated, and the figures are not at all helpful in understanding these descriptions.

A6: Thank you very much for your valuable advice. I have improved the supporting figures for the content.

C7. The authors primarily use from third-party, proprietary drawings that are irrelevant to the content presented.

A7:Thank you very much for your valuable advice. I have improved the supporting figures for the content. Irrelevant figures have been deleted.

C8. The final table includes drive classes not described at all in the article.

A8: Thank you very much for your valuable advice. I have deleted the drive types that are not described in the article from the table.

The manuscript is added as follows:

Table 1. Performance characteristics of piezoelectric drive motors with different principles in various aspects.

Principle	Ultrasonic motor	Inertial motor	Peristaltic motor
Trip	Large itinerary	Large itinerary	Large itinerary
Running speed	Extremely high （200mm/s）	Medium	Medium（0.5mm/s）
Resolution	100nm	100nm	20nm
Positioning stability	Medium	Low	High
Load	Medium	Low	High
Frequency	High	Medium	Low
Friction	High friction	Frictional	Slight friction
Fever	Fever	Mild fever	No fever
Energy efficiency	Inefficient	Relatively high efficient	High efficient
Structural complexity	Relatively high	Relatively Low	High
Control characteristics	Specific waveform	Specific waveform	Specific timing sequence
Control difficulty	Complex	Easy	Complex
Curve trajectory	Supporting	Forbidden	Supporting

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Respected Authors,

After careful reading of your manuscript, I have the following remarks:

R1: Please be consistent throughout the text when mentioning types of piezoelectric motors. Use the same expressions you have used in the Abstract.

R2: In line 36, the word "frequency" is repeated.

R3: In line 59, the reference [34] is mentioned in the context of the symmetric structure of a standing-wave ultrasonic motor. However, the reference [34] deals with a motor with an asymmetric structure. Please address this issue.

R4: The numerations of figures need to be checked because there are some inconsistencies. 

R5: Since this is a review paper, the results of the Authors should not be presented as novel achievements, i.e. the Authors should cite only their previous work. In particular, the presented work of the Authors should be cited from their previously published papers. Novel achievements should be presented in a separate manuscript submission.

R6: The quality of Figure 11 should be improved.

R7: When citing a reference in the body of the manuscript, if you want to mention the leading author's name, please use the last name (surname).

R8: Check the text in lines 243 and 244 for mistakes (motor/stator).

R9: Table 1 should be moved from the Summary and Outlook section to a separate section of the manuscript that could be called Discussions. Additionally, another table with numerical parameters of the motors should be included and discussed in the same section of the manuscript.

Kindest regards.

Author Response

For reviewer 1

 

R1: Please be consistent throughout the text when mentioning types of piezoelectric motors. Use the same expressions you have used in the Abstract.

A1:Thank you very much for your valuable advice. I have revised the descriptions of piezoelectric motor types in the subsequent sections to ensure they are consistent with the expressions in the abstract.

R2: In line 36, the word "frequency" is repeated.

A2:Thank you very much for your valuable advice. I have deleted an extra "frequency"

The manuscript is modified as follows:

The step size of ultrasonic motor under one pulse is very small, so it needs high frequency excitation

R3: In line 59, the reference [34] is mentioned in the context of the symmetric structure of a standing-wave ultrasonic motor. However, the reference [34] deals with a motor with an asymmetric structure. Please address this issue.

A3:Thank you very much for your valuable advice. I have checked and revised the content mentioned in the comments. There was indeed a contradiction, which was caused by a spelling error. I have corrected it in the content.

The manuscript is modified as follows:

Wang et al. [34] developed a standing-wave ultrasonic motor with asym-metric   structure. By exciting the piezoelectric elements attached to a metal substrate (Figure 2(a)), the driving foot generates periodic vibrations (Figure 2(b)). Ex-perimental results indicate that when the pre-tightening force is 30 N and the excita-tion voltage is 150 V, the motor achieves a maximum no-load speed of 0.12 m/s and a maximum thrust of 2.8 N.

R4: The numerations of figures need to be checked because there are some inconsistencies.

A4: Thank you very much for your valuable advice. The numbering errors in Figures 9, 22, and 23 have been corrected.

R5: Since this is a review paper, the results of the Authors should not be presented as novel achievements, i.e. the Authors should cite only their previous work. In particular, the presented work of the Authors should be cited from their previously published papers. Novel achievements should be presented in a separate manuscript submission.

A5: Thank you very much for your valuable advice. In accordance with the suggestions, when referring to our own research findings, we have cited our previously published papers. They are the 49th and 62nd references respectively.

R6: The quality of Figure 11 should be improved.

A6: Thank you very much for your valuable advice. I have replaced Figure 11 with a version of higher clarity.

The manuscript is modified as follows:

 

 

R7: When citing a reference in the body of the manuscript, if you want to mention the leading author's name, please use the last name (surname).

A7:Thank you very much for your valuable advice. I have corrected the name of each author mentioned, using their last names.

R8: Check the text in lines 243 and 244 for mistakes (motor/stator).

A8:Thank you very much for your valuable advice. I have corrected the mistake in this sentence.

The manuscript is modified as follows:

Chen [54] improved and optimized the stator structure of a flexible five-bar driven motor (Figure 15) .

R9: Table 1 should be moved from the Summary and Outlook section to a separate section of the manuscript that could be called Discussions. Additionally, another table with numerical parameters of the motors should be included and discussed in the same section of the manuscript.

A9: Thank you very much for your valuable advice. I have placed Table 1 in the newly added "Discussion" section and conducted discussions and analysis based on the motor parameters and other content in the table. The structural parameters of piezoelectric motors vary significantly. Specifically, there are substantial differences in the motors' parameters both when different applications adopt the same operating principle and when the same application uses different operating principles. Additionally, among these motors, only the rotary ultrasonic motors have standardized models available; all other types are custom-made. Given these factors, direct comparability between them does not exist. Therefore, I believe Table 2 is unnecessary

The manuscript is added as follows:

Table 1provides a qualitative comparison of the key performance characteristics of three representative piezoelectric motor types: ultrasonic motor, inertial motor, and peristaltic motor. Each type exhibits unique operational advantages and inherent trade-offs depending on the intended application scenario.

Ultrasonic motors achieve the highest running speed, reaching up to approxi-mately 200 mm/s, and are therefore suitable for high-speed motion applications such as camera autofocus, robotic actuation, and precision mechanical positioning. However, their operation relies on high-frequency frictional contact between the stator and rotor, which inevitably leads to heat generation and wear, reducing both efficiency and long-term stability. Structural complexity and waveform control also contribute to their relatively difficult control characteristics.

Inertial motors provide medium operating speed and comparable resolution (around 100 nm), achieved through stick–slip or impact drive mechanisms. Their sim-ple structure offers advantages in compactness and ease of fabrication, but their lim-ited load capacity, low positioning stability, and restricted motion trajectory (non-supporting curved motion) make them more suitable for micro-positioning stages or atomic force microscopy applications where minimal displacement and low force are required.

Peristaltic motors, in contrast, combine high positioning stability and fine resolu-tion (as small as 20 nm) with low operating frequency and minimal heat generation. Their peristaltic drive sequence allows precise and stable displacement through coor-dinated phase timing, while maintaining high efficiency. Despite their structural com-plexity and control difficulty, they are advantageous for applications that demand both precision and reliability, such as optical alignment, aerospace mechanisms, and vacu-um operation systems.

In summary, ultrasonic motors dominate in speed-oriented tasks, inertial motors excel in compact ultra-fine positioning applications, and peristaltic motors offer the best balance between efficiency, precision, and thermal stability.

This comprehensive comparison highlights the importance of selecting appropri-ate motor types according to performance requirements and control complexity in ad-vanced electromechanical systems.

Table 1. Performance characteristics of piezoelectric drive motors with different principles in various aspects.

Principle	Ultrasonic motor	Inertial motor	Peristaltic motor
Trip	Large itinerary	Large itinerary	Large itinerary
Running speed	Extremely high （200mm/s）	Medium	Medium（0.5mm/s）
Resolution	100nm	100nm	20nm
Positioning stability	Medium	Low	High
Load	Medium	Low	High
Frequency	High	Medium	Low
Friction	High friction	Frictional	Slight friction
Fever	Fever	Mild fever	No fever
Energy efficiency	Inefficient	Relatively high efficient	High efficient
Structural complexity	Relatively high	Relatively Low	High
Control characteristics	Specific waveform	Specific waveform	Specific timing sequence
Control difficulty	Complex	Easy	Complex
Curve trajectory	Supporting	Forbidden	Supporting

 

 

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Dear Authors

The manuscript looks much better now, and I think it should be considered for publication. 

Great work

Author Response

Thank you for your advice and guidance

Reviewer 2 Report

Comments and Suggestions for Authors

The authors did not address the reviewer's comments and are unaware of the importance of review articles and the methodology of creating a review article.

Author Response

For editor and reviewer

Dear editor and reviewerr,

It is a great honor to receive your letter, and we sincerely thank the editor and review experts for their careful review of our manuscript and their valuable comments, which we are more than willing to adopt.

We have carefully studied each comment and made systematic revisions to the paper to enhance its logical coherence, standardization, and academic depth. Please rest assured that we have made every effort to revise this manuscript, striving to bring it closer to the acceptance standards of your journal. We are deeply grateful to you for giving us the opportunity to revise instead of rejecting the manuscript directly. In accordance with the reviewers' comments, we have made more specific improvements to the paper.

Additionally, we would like to apologize for one matter: we have just submitted the revised manuscript. We sincerely apologize for any inconvenience caused if this submission exceeds the deadline.

Best regards.

Sincerely yours

 

1 The article does not present a review methodology. It does not describe what resources were searched to generate an objective set of descriptions, how the databases were searched, what article databases were searched, what patent databases were searched, what search methods were used, how the found materials were analyzed, what statistical analyses were performed on the found resources, etc.

A1: Thank you very much for your valuable advice. I have added a section to explain the search databases, keywords, screening criteria, and time range, so as to highlight the systematicness and objectivity of the review.

The manuscript is modified as follows:

This review adopted a structured approach to ensure completeness and objectivity. Literature searches were performed in Web of Science, Scopus, IEEE Xplore, and Google Scholar using keywords “piezoelectric motor,” “ultrasonic motor,” and “peri-staltic motor.” The search covered 1995–2025. Only peer-reviewed journal papers and patents providing quantitative analysis were included. Data were classified according to motor type, structure, and application field, forming the basis for comparative discussion.

2. In the context of the previous comment, no objective and justified classification was presented, and the operating principle for each class of measurement, drive was not described.

A2: Thank you very much for your valuable advice. I introduced the basis for classification in the introduction, and at the beginning of the chapter for each category, I described the operating principle of that type of motor.

The manuscript is modified as follows:

Based on their driving methods and operating principles, piezoelectric motors can be categorized into ultrasonic motors and piezoelectric peristaltic motors, with the primary differences lying in the method and structure used for kinetic energy conver-sion [8-11].

3. The figures are unclear and do not present the operating principles clearly. The authors confuse the descriptions of the operating principles with the actual application of a given drive/measurement type.

A3: Thank you very much for your valuable advice. The caption for each image explains the content of the image, and there are also relevant descriptions of the images in the article. Piezoelectric motors of the same type share similar operating principles, so it is unnecessary to repeat the operating principle in the description of each motor. Therefore, in the description of each motor, emphasis is placed on its characteristics.

4. The limitations of the suggested applications, especially aerospace,  were not analyzed, and no assessment of the drive/measurement was made in the context of these limitations.

A4: Thank you very much for your valuable advice. In the chapter on conclusions and trends, I have supplemented the development directions and limitations of the two types of piezoelectric motors, especially in the aerospace field.

The manuscript is modified as follows:

Ultrasonic motors feature high speed, compact structure, and a wide torque range. However, they have a relatively long steady-state time, which leads to a sharp drop in precision during low-speed operation and ultra-short displacement. To address the nonlinearity issue of ultrasonic motors, designing new motor structures (such as rhombic vibrators) or proposing new control methods (such as instantaneous driving) has become the current mainstream trend. In the aerospace field, the impact of tem-perature on the performance of motor friction materials is also a key research focus.

Peristaltic motors offer large load capacity, high precision, and power-off holding functionality. Nevertheless, their high precision is particularly dependent on high-precision guiding mechanisms. Therefore, the integrated design of peristaltic motors and guiding mechanisms is the current mainstream trend. In the aerospace field, Long-term operation may lead to contact cold welding; temperature changes can affect the piezoelectric constant, thereby reducing positioning accuracy. Future re-search should focus on temperature compensation control and anti-adhesion material design to improve reliability in aerospace missions. The cold welding issue of motor clamping mechanisms and the weight reduction of the overall motor are also hot top-ics in current research.  

5. Trends were not determined, and the development of individual methods was not assessed in the context of technological development/time.

A5: Thank you very much for your valuable advice. I have supplemented the development trends and added descriptions of trends from a temporal dimension.

The manuscript is modified as follows:

Over the past decade, ultrasonic mot  ors have evolved from single-mode to com-posite-mode structures, achieving higher torque density and control precision. Mean-while, peristaltic motors have gained attention for applications requiring large load capacity and long-term stability. Future research will focus on lightweight integrated designs, friction optimization for vacuum operation, and intelligent adaptive control methods.  

6. The operating descriptions are complicated, and the figures are not at all helpful in understanding these descriptions.

A6: Thank you very much for your valuable advice. I have refined the description of the working principle of the piezoelectric peristaltic motor section to make it easier to understand, and I have revised the captions of some images to facilitate understanding of the content.

The manuscript is modified as follows:

3. Peristaltic motor

The principle of a piezoelectric peristaltic motor is based on the inverse piezoelec-tric effect, which generates displacement and driving force. The operation of a piezoe-lectric peristaltic motor consists of three phases: clamping, pushing, and releasing. Through sequential control, the piezoelectric stack undergoes periodic expansion and contraction, enabling the coordinated movement of the clamping mechanism and the extending mechanism, thereby achieving stepping motion with controllable frequency and step size.   Piezoelectric peristaltic motors inherently offer high posi-tioning accuracy due to the small deformations produced by piezoelectric materials, which facilitate smooth motion. The excitation voltage amplitude and frequency directly influence the step size and velocity, allowing for precise displacement control. This high positioning accuracy is maintained across both large and small travel ranges. Compared to electromagnetic motors, piezoelectric peristaltic motors have advantages such as compact size and high efficiency, making them more suitable for miniaturization. As a result, they have broad application prospects in high-precision measurement and pre-cision motion control. Based on different structural characteristics and operating modes, piezoelectric peristaltic motors can be classified into two main types.

1. Linear piezoelectric peristaltic motors
2. Rotary piezoelectric peristaltic motors
3. The authors primarily use from third-party, proprietary drawings that are irrelevant to the content presented.

A7: Thank you very much for your valuable advice.

8. The final table includes drive classes not described at all in the article.

A8: Thank you very much for your valuable advice. The inertial motor is described in the chapter on other piezoelectric motors.

Author Response File: Author Response.pdf