Lung-Jieh Yang

Tamkang University · Department of Mechanical and Electro-Mechanical Engineering

This paper presents a new framework using MEMS flow sensors on turbine blades (SOTB) to investigate unsteady flow features of a rotating wind turbine. Self-heating flow sensors were implemented by the U18 complementary metal-oxide semiconductor (CMOS) MEMS foundry provided by Taiwan Semiconductor Research Institute (TSRI). Flow sensor chips with a...

As an alternative to SU-8 soft lithography, a new silicon mold process of fabricating PDMS microchannel chips was proposed. A picosecond laser is used to cut through a 550 μm thick silicon wafer and generate the original microchannel pattern with a 50 μm minimum feature size. This single-crystal silicon pattern, with the edge debris caused by laser...

This research delves into the comparative analysis of leading-edge twisting mechanisms for flapping wings, aiming to discern optimal approaches for wing rotation. High-speed photography captures flapping motion, subsequently processed using Kwon3D software and MATLAB for trajectory analysis. Lift force signals from wind tunnel tests are juxtaposed...

The purpose of the current study is to emphasize the characteristics and phenomena of leading-edge twisting in flapping wing vehicles. A fused deposition modeling (FDM) 3D printing method is applied to develop the flapping mechanisms with bevel gears to achieve the leading-edge twisting. Three flapping mechanisms were developed, including simple fl...

The design of flapping wing micro aerial vehicle (FWMAV) imposes several challenges with reference to dimensional stability for micro mechanism assembly and ability to withstand cyclic loading conditions. Earlier manufacturing methods such as injection moulding and wire cut electrical discharge (EDM) machining necessitate more human efforts, time-c...

Improving surface quality attributes is a critical task in the production of micro-sized near-net-shaped components for end-use applications using additive manufacturing techniques. In the present study, we investigated the effect of fused deposition modeling (FDM) process parameters such as layer thickness, part orientation, raster width and raste...

The problems of steady, inviscid, isentropic, irrotational supersonic plane flow passing a body with a small thickness ratio was solved by the linearized theory, which is a first approximation at and near the surface but fails at far fields from the body. Such a problem with far fields was solved by W.D. Hayes’ “pseudo-transonic” nonlinear theory i...

A double-edge triggered flip-flop (DETFF) has the distinct ability to latch data at either the rising or the falling edge of the edge unlike the single-edge triggered flip-flop (SETFF). The proposed DETFF uses parallel dual paths that work without the need of keepers for input signal boost and an inverting clock for the opposite phase operation. A...

This research aims to develop a low-cost microchannel mold for PDMS-biomedical applications using Anodic bonding, a better alternative to SU-8 mold because of its poor mechanical properties and 3D printed mold due to its surface roughness. UV Pico laser is used on a silicon wafer to cut into the desired cilia structure microchannel pattern. At high...

The reactions of vanadium redox flow batteries (VRFBs) are quite complex and the internal environment is strongly acidic. The internal voltage, current, temperature and flow distribution play a very important role in the performance of a VRFB. The VRFB, which was developed by our R&D team, encountered easy leakage of electrolytes during assembly. A...

The complementary metal-oxide-semiconductor (CMOS) process is the mainstream to fabricate integrated circuits (ICs) in the semiconductor industry. Microelectromechanical systems (MEMS), when combined with CMOS electronics to form the CMOS MEMS process, have the merits of small features, low power consumption, on-chip circuitry, and high sensitivity...

This paper presents a design of an integrated complementary metal-oxide-semiconductor (CMOS) MEMS flow sensor, which can calibrate wind speed ranging from 0-5m/s. The authors have developed flow sensors with an on-chip instrumentation amplifier using the latest UMC 0.18μm 1P6M CMOS MEMS process. The system consists of a bridge circuit, which acts a...

The Roll-to-Roll (R2R) process refers to a high-efficiency, low-cost, continuous production method. The roll material used for processing is a flexible plastic or metal film. In many R2R processes, polarizing films are high-precision products with a high output value. In the production of conventional polarizers, product inspection will only be car...

近年來，通過微流道分離不同尺寸顆粒的研究引起了人們的興趣，這項研究的主要關注點是將微顆粒隔離到特定的出口。目前的工作高度關注微流體晶片的設計和數值分析，以及使用蜻蜓皺褶翼結構和纖毛壁等特殊結構來捕獲微顆粒。特殊的仿生皺褶翼結構係模仿蜻蜓翅膀的橫截面並予以縮小，纖毛微結構則仿自人體上皮末端細支氣管之外形並予以縮小。本文首先發現蜻蜓皺褶翼結構在下游處產生阻塞現象(圖1)，而定義出所謂二級出口，以及一進二出的分離器設計。接著針對圖2兩種分離器晶片設計 2-6 毫米的不同流道總長度，並進行微顆粒流動模擬，蜻蜓皺褶翼結構和纖毛壁的厚度均指定為 80 微米。COMSOL Multiphysics 軟體的流體粒子相互作用 (FPI)模組，用於進行本數值研究的瞬態求解。入口隨時間均勻施放 5 µm 和 20...

拍翼微型飛行器（FWMAVs）模擬了鳥類和昆蟲的小空間靈巧飛行、懸停和節能等特性，對未來仿生飛行的發展具有啟示意義。在設計 FWMAV 時，需要詳細的非定常空氣動力學信息。除了計算流體力學 (CFD) 技術之外，還需要流動可視化技術來協助釐清基本氣動力機制。本文創新性地利用皂膜可視化技術，以高速攝影分別記錄了10厘米翼展FWMAV的縱向（圖1）和橫向（圖2）兩種二維皂膜流場成像。不同於傳統煙霧追踪方法的只限於定性比較，本文詳述了皂膜圖像與流場的理論關連與後續影像數據處理，解釋如何將皂膜成像量化為升力和推力，並將相應的結果與風洞力測量數據進行了初步比較（圖3）

Quadcopters represent rotary wing configuration of the Unmanned Aerial Vehicles (UAVs) with immense application potential in industrial and strategic contexts. Tradeoff between flight endurance and payload capacity renders design optimization of UAVs a critical activity with substantial impact on the application possibilities. Among the structural...

The study of separating different sizes of particles through a microchannel has been an interest in recent years and the primary attention of this study is to isolate the particles to the specific outlets. The present work highly focuses on the design and numerical analysis of a microchip and the microparticles capture using special structures like...

Flapping wing micro-air-vehicles (FWMAVs) animate the small-space dexterous flight, hovering, and energy-saving characteristics of birds and insects, and are believed to have enlightenment for the development of bionic flight in the future. When designing FWMAVs, detailed unsteady aerodynamic information is required. Besides the computational fluid...

It is an idea of developing the microchannel-type, silicone (PDMS) face mask, which can filter out the aerosol with the virus. The new PDMS mask has a specific ciliated microchannel design, which has several advantages over the ordinary masks: ➢Effectively filtrate 70% 5um aerosol, comparable to current masks ➢ Bio-compatible and waterproof. ➢ H...

In this paper, we report an optimized CMOS compatible MEMS thermoresistive calorimetric air velocity (TMCV) sensor to measure small air velocity in an indoor environment for the application of human thermal comfort sensing. The sensor is comprised of two upstream thermistors, two downstream thermistors, and a micro-heater placed in between the upst...

The development of a flapping wing micro-aerial vehicle mechanism with a high strength-to-weight ratio to withstand high flapping frequency is of significant interest in aerospace applications. The traditional manufacturing methods such as injection moulding and wire-cut electrical discharge machining suffer from high cost, labour intensiveness, an...

This paper presents an active wing rotation mechanism for FWMAVs. New types of servo based flapping mechanisms were developed and added with set of differential gears to achieve wing rotation. The mechanisms were designed and assembled in such a way that the wing rotation occurs only at pronation and supination and mechanical stoppers were added in...

A flapping wing micro air vehicle (FWMAV) demands high lift and thrust generation to achieve good flight maneuverability. Researches regarding the FWMAV improvement need the on-site lift information and measurement. In this case, microelectromechanical systems (MEMS) flow sensors on a flapping wing can be helpful in detecting the real-time downwash...

A flapping wing micro air vehicle (FWMAV) demands high lift and thrust generation for a desired payload. In view of this, the present work focuses on a novel way of enhancing the lift characteristics through integrating check-valves in the flapping wing membrane. Modal analysis and static analysis are performed to determine the natural frequency an...

This paper deals with the fabrication, aerodynamic measurement, and performance evaluation of the corrugated wing patterns on a flapping wing micro air vehicle (FWMAV). The corrugated wing pattern is generally seen in insects. Insect wings with their corrugated topological features give themselves high load-bearing capacity during flapping and hove...

This book is about the aircraft developments of Republic of China (ROC) from 1912-2023. The major content is regarding the Aeronautical Industry Development Center (AIDC) or 漢翔 in Taiwan.

This note presents the time-averaged inertial force which relates to the velocity difference between the final and initial states of a flapping wing motion. For the periodic flapping motion with identical final and initial velocities, there are no inertial force contribution to the time-averaged lift. Therefore, the wake capture mechanism proposed...

This book comprises select proceedings of the International Conference on Design, Materials, Cryogenics and Constructions (ICDMC 2019). The chapters cover latest research in different areas of mechanical engineering such as additive manufacturing, automation in industry and agriculture, combustion and emission control, CFD, finite element analysis,...

This paper presents a methodology for designing of flapping mechanisms and rapid fabrication using 3D printing (3DP) technique for subsequent application in micro aerial vehicles. A key feature of the present study is constraining of the mechanism weight and aerial vehicle size to stipulated limits while optimising the functional features of flap a...

This paper presents a methodology for designing of flapping mechanisms and rapid fabrication using 3D printing (3DP) technique for subsequent application in micro aerial vehicles. A key feature of the present study is constraining of the mechanism weight and aerial vehicle size to stipulated limits while optimising the functional features of flap a...

The book includes the best articles presented by researchers, academicians and industrial experts at the International Conference on “Innovative Design and Development Practices in Aerospace and Automotive Engineering (I-DAD 2018)”. The book discusses new concept in designs, and analysis and manufacturing technologies for improved performance throu...

This study investigates three-dimensional (3D) flow fields around a flapping wing with a span of 20 cm. Numerical simulations are performed by varying the simulation mesh density for a half-flapping-wing profile with wind tunnel domain for flapping stroke angles of 53° and 90°. Wind velocities ranging from 1 to 3 m/s, variation in flapping frequenc...

In recent years, the development of green energy sources, such as fuel cell, biomass energy, solar energy, and tidal energy, has become a popular research subject. This study aims at a flexible four-in-one microsensor, which can be embedded in the proton exchange membrane fuel cell (PEMFC) for real-time microscopic diagnosis so as to assist in deve...

This paper presents the development of hardware module to perform versatile flight controls of flapping wing micro air vehicles (FWMAVs) or ornithopters. Firstly the authors survey the developed avionics, including the configurations of full integration and with discrete components, respectively for flight and control of FWMAVs in the literature. M...

Experimental assessment of lift and thrust forces of flapping wing micro aerial vehicles (FWMAVs) is of paramount interest to assess its payload carrying capability. In this work, a simple and cost effective test bench is developed to measure the forces of ornithopter. Two compressive load cells are calibrated and assembled in an appropriate mode t...

This study investigates three-dimensional (3D) flow fields around a flapping wing with a span of 20 cm. Numerical simulations are performed by varying the simulation mesh density for a half-flapping-wing profile with wind tunnel domain for flapping stroke angles of 53 and 90. Wind velocities ranging from 1 to 3 m/s, variation in flapping frequency...

Application of rapid prototyping (RP) techniques such as stereolithography, fused deposition modelling and selective laser sintering in the development of complex engineering systems is on upsurge due to associated functional advantages such as time-compression, designfreedom and mass-customisation. This paper examines the feasibility of using vari...

According to Lissaman and Shollenberger’s article published in Science in 1970, birds fly in formation to reduce the overall energy expenditure for flight. Thus, this work adopted the same principle of flight formation to ornithopters to save energy. Two experiments and one numerical simulation try are described herein. In the first experiment, a r...

This paper presents the results of exploratory studies for facilitating the direct use of 3D printed parts in design and development of micro aerial vehicles (MAV). 3D printing processes of stereolithography and fused deposition modeling are investigated as the candidate prototyping options. Custom developed electro-chemical and mechanical processe...

Regarding the 15 gram-weight flapping micro-air-vehicles (FMAVs) or micro ornithopters, how to prolong the operation time and improve the flight control is very critical to their scenario of development. Using the available transducer devices, this work presents four new features for ornithopters and the corresponding feasibility discussion respect...

This paper deals about the dynamic behavior of flapping wing with an aid of stereo photography measurement using charge coupled device (CCD) camera. The three dimensional (3D) flapping motion was captured and coordinates are measured with the specific markers on the wing. The curved surface fitting was obtained from the 3D discrete coordinates usin...

This paper presents the comparison between the force balance method and the surface energy method in deriving surface tension forces of some microelectromechanical systems (MEMS) problems. For studying the force balance of the capillary rise in the wick structure of heat pipes or heat spreaders, not only the surface tension at the three-phase inter...

In the body of research relevant to high-performance flapping micro air vehicles (MAV), development of light-weight, compact and energy-efficient flapping mechanisms occupies a position of primacy due to its direct impact on the flight performance and mission capability. Realization of such versatile flapping mechanism with additional ability of pr...

This note presents an elasto-capillary model of a cantilever subject to capillary stiction during drying process of removing sacrificial layers in MEMS. Similar to the dynamic analysis of the electrostatic pull-in of electrostatic micro actuators, the cantilever beam tends to be pulled down to the substrate due to the nonlinear capillary force with...

Autonomous control of Flapping Wing Vehicles (FWVs) through sophisticated software units is challenging due to its inherent complex motion characteristics. This article emphasize on the development of graphical user interface (GUI) for the control of FWVs to achieve superior maneuverability. A vision based computer control interface is developed fo...

This note presents an elasto-capillary model of a cantilever subject to capillary stiction during drying process of removing sacrificial layers in MEMS. Similar to the dynamic analysis of the electrostatic pull-in of electrostatic micro actuators, the cantilever beam tends to be pulled down to the substrate due to the nonlinear capillary force with...

This paper presents the hyper-elastic Latex film as the new material for flapping wings novelly. Compared to one of the conventional flapping wings using PET, the new Latex wing reduces the noise with 15.93 dB at least. Both wings have a wingspan of 20 cm and work at the flapping frequency of 13.3 Hz. The leading edge spars and the stiffened ribs o...

In the body of research relevant to high-performance flapping micro air vehicles (MAV), development of light-weight, compact and energy-efficient flapping mechanisms occupies a position of primacy due to its direct impact on the flight performance and mission capability. Realization of such versatile flapping mechanism with additional ability of pr...