本研究著重於微機電系統(MEMS)流量感測器在撲翼機構上的應用與整
合，藉由從撲翼過程所產生的非穩態流場中，旨在探究感測器之校準和精確 度量測，以提高對微型飛行器(MAV)的空氣動力特性和飛行性能之理解。 MEMS 流量感測器以其靈敏度和輕量化特性而聞名，在精確檢測微小氣流和 測量撲翼產生的不穩定流動場方面具有前所未有的優勢。此研究亦論及流量 感測器之封裝，並使用 Cadence 軟體進行設計並透過 U18MEMS 製程，將 UMC 0.18μm 和 1P6M 製程整合 MEMS 後處理技術。這些感測器係利用 CMOS 技術製造的壓阻元件，藉偵測流場進而引起電阻變化，因此需要再進 行校準才能提升測量之精確度。此外作者針對感測器亦有採用聚對二甲苯塗 佈技術。感測器校準條件為在風洞中以不同的風速(0-10m/s)和不同的飛行 攻角(0-90 度)之設定中採用商用數據擷取器 (DAQ970A)進行量測，其中單 一感測器靈敏度為-18.9 μV/V/m/s/mW。隨後將校準過後的感測器安裝在兩個 TKU MEMS 團隊所設計之 FWMAV 機構:Type-A1 (原始撲翼機型)和 Type- B1(翼旋轉設計之機構)撲翼機構的翼前緣和平均空氣動力翼弦(MAC) 上， 並將撲動機放入風洞內以自由流速 (U¥ >0) 進行測試，找出座標位置流度和 感測器輸出升力訊號之關聯性。此研究描述描述 MEMS 流量感測器整合到撲 翼上的一個創新的方法和實用性，促進了 MAV 技術和設計的進步。

This research investigates the integration of microelectromechanical systems (MEMS) flow sensors onto flapping wings, aiming for calibration and accuracy, measure unsteady flow phenomena generated by flapping wings to enhance aerodynamic understanding and flight performance of micro air vehicles (MAVs). MEMS flow sensors, renowned for their sensitivity and lightweight properties, offer unprecedented advantages in accurately detecting minute airflow and measuring unsteady flow phenomena generated by flapping wings. The study focuses on a sensor package comprising of a flow sensor, designed using Cadence software and implemented through the U18MEMS process, combining UMC 0.18 μm and 1P6M processes with MEMS post-processing. Utilizing piezoresistive elements fabricated via CMOS technology, these sensors detect strain-induced resistance changes caused by flow, necessitating calibration for accurate measurement. Later the sensor is introduced to parylene where the author choose selective parylene coating. Calibration is performed in a wind tunnel across various wind velocities (0-10 m/s) at different attack of angles (0°-90°) and the sensor alone has a sensitivity of -18.9 μV/V/m/s/mW with the speed range of 0-6 m/s, employing a commercial data acquisition system (DAQ970A). The calibrated sensors are subsequently mounted on the leading edge and mean aerodynamic chord (m.a.c.) of flapping wing’s (FWs), specifically two TKU MEMS group FWMAV mechanisms: Type-A1 (simple flapping) and Type-B1 (wing rotation) to find out point velocity and correlate sensor signals to the lift forces by Placing the flapping bird inside a wind tunnel and tested for free stream velocity (U¥ > 0). This abstract encapsulates the innovative approach and practical implications of integrating MEMS flow sensors onto flapping wings, facilitating advancements in MAV technology and aerodynamic design.

TABLE OF CONTENTS

Acknowledgement	3
Abstract:	II
TABLE OF CONTENTS	IV
LIST OF FIGURES	VI
LIST OF TABLES	IX
CHAPTER 1: INTRODUCTION	1
1.1 Sensors and Wings	1
1.2 CMOS and MEMS	5
1.2.1 CMOS	5
1.2.2 MEMS	5
1.2.3 Integration of CMOS and MEMS	6
1.3 CMOS MEMS Flow Sensor	7
1.3.1 Key features and advantages of CMOS MEMS flow sensors	7
1.3.2 Applications of CMOS MEMS across various industries	7
1.4 Reliability of MEMS Flow Sensors	9
1.5 Research Motivation	10
CHAPTER 2: REVIEW OF PRIOR RESEARCH AND COMPARATIVE ANALYSIS OF 3D PRINTING MATERIALS	11
2.1 First Generation MEMS Flow Sensor	11
2.2 Printing of Flapping Mechanism	13
2.2.1 Fused deposition modelling (FDM)	13
2.2.2 Materials used for printing of mechanisms	15
2.2.3 Stereolithography	16
2.2.4 Materials used for printing flapping mechanisms	18
2.3 Flapping Mechanisms	19
2.3.1 Type-A1: simple flapping mechanism	19
2.3.2 Type-B1: servo-integrated bevel gear wing rotation mechanism	20
CHAPTER 3: EXPERIMENTAL SETUP	22
3.1 Removal of Passivation Layer	22
3.2 Parylene Coating	26
3.3 Experimental Equipment	29
3.3.1 Measurement instrument	29
3.3.2 Power supply	29
CHAPTER 4: CALIBRATION TESTING OF MEMS FLOW SENSOR	31
4.1 Experimental Procedure	31
4.2 Calibration Test of The Sensor In The Wind Tunnel	36
4.3 Summary on Calibration Testing of MEMS Flow Sensor	43
CHAPTER 5: MEMS FLOW SENSORS ON FLAPPING WINGS	45
5.1 Testing of MEMS Flow Sensor on Flapping Wing (U=0)	45
5.2 Testing of MEMS Flow Sensor on Flapping Wing(U > 0)	49
5.3 Correlation of Lift and Thrust Force With Flapping Data	53
5.4 Summary on Findings of Flapping Wing Test	58
CHAPTER 6: CONCLUSION AND FUTURE WORK	59
6.1 Conclusion	59
6.2 Future Work	60
REFERENCES	61
APPENDIX A Calibration testing	64
APPENDIX B Flapping wing testing	71
APPENDIX C Matlab processing	74

LIST OF FIGURES


Figure 1.1   Flexible MEMS shear stress sensor	2
Figure 1.2   Modified MAV 	3
Figure 1.3   (a-b) Photograph and SEM image of the fabricated differential pressure sensor; (c) The fabrication process for the sensor; (d) Characteristics of the sensor for differential pressure	4
Figure 1.4   The first micromotor in the world	6
Figure 1.5   Hybrid approach (left) vs. monolithic integration of MEMS and CMOS (right)	6
Figure 2.1   Wind tunnel experimentation setup	11
Figure 2.2   Experimental results of wind tunnel test	12
Figure 2.3   Zortax M200 3D printer	14
Figure 2.4   Surface interface of Z-suit software	15
Figure 2.5   Phrozen Sonic Mighty 8k UV printer	17
Figure 2.6   Surface interface of chitubox software	18
Figure 2.7   Design prototype of the Type-A1 mechanism 	20
Figure 2.8   Design prototype of the Type-B1 mechanism	21
Figure 3.1   Metal 7 layer covering the pads of the sensor	22
Figure 3.2   Automated probing microscope	23
Figure 3.3   Specimen placed on the test bed of automated probing microscope	24
Figure 3.4   Laser precision settings for removal of metal 7 layer.	24
Figure 3.5   Metal 7 layer removed after laser treatment	25
Figure 3.6   SB32 package of the sensor	25
Figure 3.7   Sensors placed in a PDMS solution	26
Figure 3.8   5 µm parylene coated sensor	27
Figure 3.9   10 µm parylene coated sensor	27
Figure 3.10 10 µm parylene coated sensors	28
Figure 3.11 Output voltage readings from the sensor	29
Figure 3.12  Power supply	30
Figure 4.1   Resistance measurement by using the multi meter	31
Figure 4.2   Wheatstone bridge simulator interface	32
Figure 4.3   (a) Sensor stand for calibration test; (b) PCB circuit made for testing.	33
Figure 4.4   (a) PCB circuit made for the sensor; (b) Sensor mounted on the board.	33
Figure 4.5   Calibration test stand design in solid works	34
Figure 4.6   GX430L EDM machine	35
Figure 4.7   Fabricated test stand for calibration	35
Figure 4.8   Wind tunnel experiment setup	36
Figure 4.9   Analysis of instantaneous AOA at different positions of the flapping wing 	37
Figure 4.10  Sensor placed in different AOA’s (a) 90; (b) 80; (c) 70;(d) 60; (e) 50; (f) 40; (g) 30; (h) 20; (i) 10; (j) 0.	38
Figure 4.11  (a) Raw data after the calibration test of sensor; (b) Fast Fourier Transform (FFT); (c) Applying cut off frequency (3Hz) to eliminate noise.	39
Figure 4.12  Calibration test results of different AOA (0-90º).	40
Figure 4.13  Curve fitting graph (0-10 m/s).	42
Figure 4.14  Curve fitting graph (0-6 m/s).	42
Figure 4.15  Curve fitting with calibration results of different AOA(0-90º).	43
Figure 5.1    Schematics of sensor placed on the flapping wings	46
Figure 5.2    Testing setup of MEMS flow sensor on the flapping bird at U = 0	46
Figure 5.3    Flapping wing test results of voltage output vs wind speed at U = 0:     (a) Type-A1, leading edge; (b) Type-A1, m.a.c.; (c) Type-B1, leading edge; (d) Type-B1, m.a.c.	48
Figure 5.4    Experimental setup of the flapping bird in a wind tunnel. (unit:cm)	50
Figure 5.5    (a) Experimental setup of a flapping bird inside a wind tunnel; (b) MEMS flow sensors placed on the leading edge of the flapping wings.	51
Figure 5.6    Flapping wing test results with voltage output vs. wind speed at U > 0 : (a) Type-A1, leading edge; (b) Type-A1, m.a.c.; (c) Type-B1, leading edge; (d) Type-B1, m.a.c.	52
Figure 5.7    (a-c) Calibrated sensor data; (a1-c1) Lift data measured by force gauge of Type-A1 mechanism at 25° AOA.	54
Figure 5.8    (a-c) Calibrated sensor data; (a1-c1) Lift data measured by force gauge of Type-B1 mechanism at 25° AOA.	55
Figure 5.9    (a-c) Calibrated sensor data; (a1-c1) Thrust force data measured by force gauge of Type-A1 mechanism at 25° AOA.	56
Figure 5.10   (a-c) Calibrated sensor data; (a1-c1) Thrust force data measured by force gauge of Type-B1 mechanism 25° AOA.	57
Figure A6.1   The bulky setup used for calibration test in earlier cases	64
Figure A6.2   Setup fly off due to wind speed because restriction of wind flow	64
Figure A6.3   Calibration test results at 0 AOA(a-c).	65
Figure A6.4   Calibration test results at 10 AOA(a-c).	66
Figure A6.5   Calibration test results of 20 AOA(a-c).	67
Figure A6.6   Calibration test results of 30 AOA(a-c).	68
Figure A6.7   Calibration test results of 40 AOA(a-c).	69
Figure A6.8   Calibration test results of 50 AOA(a-c).	70
Figure A6.9   Testing of flapping bird at 15 (AOA)	71
Figure A6.10  Sensors placed on mean aerodynamic chord (m.a.c.)	71
Figure A6.11  Sensor signals on flapping bird at 15 (AOA) (a-b).	72
Figure A6.12  Sensor signals on flapping bird at 15 (AOA) (a-b).	73
Figure A6.13  Matlab processed images of Type-A1 lift force (a-c).	76
Figure A6.14  Matlab processed images of Type-B1 lift forces (a-c).	77

LIST OF TABLES

`
Table 2.1  Printing specifications of Zortax M200 3D printer	14
Table 2.2  Properties of materials used to print mechanisms	16
Table 2.3  Properties of UV printing machine	17
Table 2.4  Properties of a Rock-Black stiff resin	19
Table 3.1  Technical output specifications	30
Table 4.1  Resistance values of sensors	32

REFERENCES
[1] M. Keennon and J. Grasmeyer, "Development of two MAVs and vision of the future of MAV design," in AIAA International Air and Space Symposium and Exposition: The Next 100 Years, 2003, p. 2901.
[2] S. Palleboina and K. Pallela, "MAV Design Aspects Using MEMS," Biophysics of Insect Flight, pp. 143-154, 2021.
[3] N. Mahalik, "Principle and applications of MEMS: a review," International journal of manufacturing technology and management, vol. 13, no. 2-4, pp. 324-343, 2008.
[4] A. Huang et al., "Applications of MEMS devices to delta wing aircraft-From concept development to transonic flight test," in 39th Aerospace Sciences Meeting and Exhibit, 2001, p. 124.
[5] L. Lin and W. Yun, "MEMS pressure sensors for aerospace applications," in 1998 IEEE Aerospace Conference Proceedings (Cat. No. 98TH8339), 1998, vol. 1: IEEE, pp. 429-436.
[6] Y. Javed, M. Mansoor, and I. A. Shah, "A review of principles of MEMS pressure sensing with its aerospace applications," Sensor Review, vol. 39, no. 5, pp. 652-664, 2019.
[7] S. Spearing, "Materials issues in microelectromechanical systems (MEMS)," Acta materialia, vol. 48, no. 1, pp. 179-196, 2000.
[8] S. Ho, H. Nassef, N. Pornsinsirirak, Y.-C. Tai, and C.-M. Ho, "Unsteady aerodynamics and flow control for flapping wing flyers," Progress in aerospace sciences, vol. 39, no. 8, pp. 635-681, 2003.
[9] S. Shkarayev and D. Silin, "Aerodynamics of flapping-wing micro air vehicles," in 47th AIAA aerospace sciences meeting including the new horizons forum and aerospace exposition, 2009, p. 878.
[10] S. Deng, M. Percin, and B. van Oudheusden, "Experimental investigation of aerodynamics of flapping-wing micro-air-vehicle by force and flow-field measurements," AIAA Journal, vol. 54, no. 2, pp. 588-602, 2016.
[11] L.-J. Yang, F.-Y. Hsiao, W.-T. Tang, and I.-C. Huang, "3D flapping trajectory of a micro-air-vehicle and its application to unsteady flow simulation," International Journal of Advanced Robotic Systems, vol. 10, no. 6, p. 264, 2013.
[12] H. Takahashi, "MEMS-Based Micro Sensors for Measuring the Tiny Forces Acting on Insects," Sensors, vol. 22, no. 20, p. 8018, 2022.
[13] L.-J. Yang, C.-K. Hsu, J.-Y. Ho, and C.-K. Feng, "Flapping wings with PVDF sensors to modify the aerodynamic forces of a micro aerial vehicle," Sensors and Actuators A: Physical, vol. 139, no. 1-2, pp. 95-103, 2007.
[14] R. Yanagisawa et al., "Wearable Vibration Sensor for Measuring the Wing Flapping of Insects," Sensors, vol. 21, no. 2, p. 593, 2021.
[15] H. Takahashi, H. Tanaka, K. Matsumoto, and I. Shimoyama, "Differential pressure distribution measurement with an MEMS sensor on a free-flying butterfly wing," Bioinspiration & Biomimetics, vol. 7, no. 3, p. 036020, 2012.
[16] G. Pillai and S.-S. Li, "Piezoelectric MEMS resonators: A review," IEEE Sensors Journal, vol. 21, no. 11, pp. 12589-12605, 2020.
[17] A. Uranga, J. Verd, and N. Barniol, "CMOS–MEMS resonators: From devices to applications," Microelectronic Engineering, vol. 132, pp. 58-73, 2015.
[18] H. Bhugra and G. Piazza, Piezoelectric MEMS resonators. Springer, 2017.
[19] J. Van Beek and R. Puers, "A review of MEMS oscillators for frequency reference and timing applications," Journal of Micromechanics and Microengineering, vol. 22, no. 1, p. 013001, 2011.
[20] W.-T. Hsu, "Recent progress in silicon MEMS oscillators," in Proceedings of the 40th Annual Precise Time and Time Interval Systems and Applications Meeting, 2008, pp. 135-146.
[21] R. Mestrom, R. Fey, J. Van Beek, K. Phan, and H. Nijmeijer, "Modelling the dynamics of a MEMS resonator: simulations and experiments," Sensors and Actuators A: Physical, vol. 142, no. 1, pp. 306-315, 2008.
[22] W. Burger and R. Reif, "MOSFET characteristics in low-temperature plasma- enhanced chemical vapor deposited epitaxial silicon," IEEE electron device letters, vol. 7, no. 4, pp. 206-207, 1986.
[23] A. Witvrouw et al., "Poly-SiGe, a superb material for MEMS," MRS Online Proceedings Library (OPL), vol. 782, p. A2. 1, 2003.
[24] C. Van Hoof, K. Baert, and A. Witvrouw, "The best materials for tiny, clever sensors," Science, vol. 306, no. 5698, pp. 986-987, 2004.
[25] A. Witvrouw, "CMOS-MEMS integration: why, how and what?," in
Proceedings of the 2006 IEEE/ACM international conference on Computer-
aided design, 2006, pp. 826-827.
[26] S. Sedky, A. Witvrouw, and K. Baert, "Poly SiGe, a promising material for
MEMS monolithic integration with the driving electronics," Sensors and
Actuators A: Physical, vol. 97, pp. 503-511, 2002.
[27] A. E. Franke, J. M. Heck, T.-J. King, and R. T. Howe, "Polycrystalline silicon-
germanium films for integrated microsystems," Journal of
microelectromechanical systems, vol. 12, no. 2, pp. 160-171, 2003.
[28] A. Mehta et al., "Novel high growth rate processes for depositing poly-SiGe
structural layers at CMOS compatible temperatures," in 17th IEEE International Conference on Micro Electro Mechanical Systems. Maastricht MEMS 2004 Technical Digest, 2004: IEEE, pp. 721-724.
[29] F. Ejeian et al., "Design and applications of MEMS flow sensors: A review," Sensors and Actuators A: Physical, vol. 295, pp. 483-502, 2019.
[30] Q. Kang, Y. Lin, and J. Tao, "A Reliability Analysis of a MEMS Flow Sensor with an Accelerated Degradation Test," Sensors, vol. 23, no. 21, p. 8733, 2023.
[31] A. Acovic, G. La Rosa, and Y.-C. Sun, "A review of hot-carrier degradation mechanisms in MOSFETs," Microelectronics Reliability, vol. 36, no. 7, pp. 845-869, 1996/07/01/ 1996, doi: https://doi.org/10.1016/0026-2714(96)00022- 4.
[32] J. Kohout, "Three-parameter Weibull distribution with upper limit applicable in reliability studies and materials testing," Microelectronics Reliability, vol. 137, p. 114769, 2022/10/01/ 2022, doi: https://doi.org/10.1016/j.microrel.2022.114769.
[33] W. Reshmi, "Integrated CMOS Mems Flow Sensor and Its Application to Flapping Wings," Tamkang University Department of Mechanical and Electro-Mechanical Engineering, 2022.
[34] S. Kompala, "Wing Rotation Mechanisms Using Bevel Gears for Ornithopters," Tamkang University Department of Mechanical and Electro- Mechanical Engineering, 2020.
[35] 費約瑟, "互補式金氧半微機電感測器之製作封裝與無線訊號擷取," 2023.
[36] D. Yu et al., "3D GOI CMOSFETs with novel IrO/sub 2/(Hf) dual gates and high-k dielectric on 1P6M-0.18/spl mu/m-CMOS," in IEDM Technical Digest. IEEE International Electron Devices Meeting, 2004., 2004: IEEE, pp. 181- 184.
[37] K.-K. Huang, M.-J. Chiang, and C.-K. C. Tzuang, "A 3.3 mW K-Band 0.18- $\mu $ m 1P6M CMOS Active Bandpass Filter Using Complementary Current-Reuse Pair," IEEE microwave and wireless components letters, vol. 18, no. 2, pp. 94-96, 2008.
[38] R. M. Vinella, G. Van der Plas, C. Soens, M. Rizzi, and B. Castagnolo, "Substrate noise isolation experiments in a 0.18 μm 1P6M triple-well CMOS process on a lightly doped substrate," in 2007 IEEE Instrumentation & Measurement Technology Conference IMTC 2007, 2007: IEEE, pp. 1-6.
[39] S. W. Glunz and F. Feldmann, "SiO2 surface passivation layers–a key technology for silicon solar cells," Solar Energy Materials and Solar Cells, vol. 185, pp. 260-269, 2018.
[40] L.-J. Yang et al., "Aerodynamic evaluation of flapping wings with leading- edge twisting," Biomimetics, vol. 8, no. 2, p. 134, 2023.
[41] L.-J. Yang and B. Esakki, Flapping Wing Vehicles: Numerical and Experimental Approach. CRC Press, 2021.
[42] W.-C. Wang, "Fabrication of Check Valves on Flapping Wings for Lift Enhancement," Tamkang University, Department of Mechanical and Electro- Mechanical Engineering, 2019.