Characterization of electrothermal micro-actuator using image processing algorithm

3D fabrication technology has gained a lot of attention recently, with the rapid fabrication of 3D parts for use in various applications. This article presents an electrothermal micro-actuator's characterization study fabricated using digital light processing (DLP), one of the 3D manufacturing methods. This actuator has been designed and fabricated to move in two directions according to the specified criteria. Three different experiments were conducted during the fabrication process. During the fabrication process of the first two experiments, deterioration or breakage occurred in the micro-actuator structure. These problems did not occur in the fabrication of the 3rd experiment. A characterization test setup was created to observe the displacement of the actuator under different operating voltage values. This setup includes an optical microscope and digital camera to observe displacements at the probe station. An image processing algorithm was used to detect the observed displacements. In experimental studies, the operating voltage was increased from 0V to 1V until deterioration or breakage in the micro-actuator structure was observed. When 6V voltage is applied to the micro-actuator, a maximum displacement of 3.84 mu m occurred in each direction. When more than 6V voltage is applied to the micro-actuator, deformations or breaks occurred in the actuator arms. As a result, the micro-actuator's design is bi-directional, so its maximum displacement is 7.68 mu m

FABRICATION OF MEMS-BASED ELECTROTHERMAL MICROACTUATORS WITH ADDITIVE MANUFACTURING TECHNOLOGIES

This study aimed to fabricate a bidirectional electrothermal microactuator that can be produced with the conventional micro-electromechanical system (MEMS) fabrication technique, using two-photon polymerization (2PP) and projection micro-stereolithography (P mu SL) methods and to compare these methods with each other. The electrothermal microactuator that can move in two directions was designed in accordance with determined criteria. Although the same design was used for the 2PP and P mu SL methods, the supporting structures were not produced with the P mu SL method. For the P mu SL method, the actuator was produced by removing the supports from the original design. Although 2-mu m-diameter supports could be fabricated with the 2PP method, it was not possible to produce them with the P mu SL method. Furthermore, the 2PP method was found to be better than the P mu SL for the production of complex, non-symmetric support structures

Influence of pretension on mechanical properties of carbon fiber in the filament winding process

The present study has investigated the effect of the roving tension (pretension force) on the strength of continuous carbon fiber used in the Filament Winding (FW) process. Pretension force is generally applied to composite products manufactured by FW technology to lay out the carbon fiber onto the cylindrical tube in a correct way. However, a considerable amount of damage occurs in the fibers during fiber movement trough pulleys in the pretension unit. A winding system was designed to simulate the process to understand the effects of the parameters such as roving tension, pulley diameter, and contact angle between pulley and fiber. Several experimental tests have been performed by changing pulley diameters and tension forces to understand the effect of these parameters. According to these experiments, the angle between the pulley and the amount of force applied to the carbon fiber generate the damage on the carbon fiber. Tension tests were also conducted to evaluate the strength of the damaged and undamaged carbon fiber. Experimental results indicate that the tensile strength of carbon fiber is reduced by 10 to 43% because of a change to the roving tension (pretensioning) parameters

Damage detection of carbon fibers in filament winding machines using an electrical resistance method

The aim of this research project is to detect the presence of fiber damage which occurs during the pretensioning of carbon fibers during the Filament Winding (FW) manufacturing process. The property of electrical conductivity of the carbon fibers was investigated to determine the existence and level of fiber damage. An experimental system was designed and developed to simulate the pretension system of a FW machine and measure the electrical change of broken fibers during the winding process. Toray T1000G-12K type of carbon fiber was used in the experimental stage of this research project. The damaged fibers were later used to obtain tension test pieces to evaluate the amount of damage which was caused by the pretensioning unit. The tension test was carried out according to ASTM 4018-99. The results demonstrated that the electrical conductive property of carbon fibers can be effectively used to evaluate the damage which occurs during the pretensioning in the FW process

Nı Labview ile Optik Kağıt Okuma Uygulamasının Geliştirilmesi ve Uygulaması

Kıcık, Ümit (Arel Author)This study aims to develop a software, which can read the test type examination paper with less effort under low cost. The software is based on optical mark recognition system in order to read multiple choice test exams answer sheets based on image processing. The reading and evaluation of exam papers is an important activity that takes a significant portion of the trainers' time. Accurate implementation of this process is extremely important in terms of evaluation of education. In the application part of this work, a software realized by using the NI LabVIEW software was used to automatically read answer papers scanned in JPEG format in any copier without the need for an optical reading device. The preliminary tests of the developed software were made with 50 answer papers prepared and it was seen that successful results were obtained. The system, which requires only a computer and JPEG format scanning, is evaluated to have the potential to be used by a much wider set of teachers besides simplicity and high speed and accuracy compared to expensive optical reading devices

Caliper simulation using computer for vocational and technical education

In this study a caliper simulation was developed as computer application for using in the Vocational Education and Training ( VET) and Distance-based training. This simulation was developed for teaching the caliper as measurement tool based Metric and Whitworth measurement systems. The developed caliper simulation introduced in detail step by step as user guide. The vernier scales are simulated as 1/10, 1/20 and 1/50 for metric measurement system and 1/64, 1/128 and 1/1000 for Whitworth measurement system. This simulation can easily be download and setup as computer software. To the best of the authors' knowledge, this is the most important application for students to study everywhere they would like

5-DOF serial robot manipulator design, application and inverse kinematic solution through analytical method and simple search technique

WOS: 000523686500015In this study a five Degrees of Freedom (DOF) serial robot manipulator was designed and implemented. The inverse kinematics problem, which has not exact analytical solution (only one inverse kinematic solution for a predefined end effector position in three dimensional space), of the robot mechanism was solved by using the combination of the analytical method and a simple search method. In order to use the proposed method in real-time applications, the method is designed so that it can be used to solve the inverse kinematics problem for the next point of the end-effector while the mechanism is working. Moreover, so that to control the implemented mechanism, a user interface program was written by using Visual Basic programming language. Finally, the proposed inverse kinematic solution method was tested on two different trajectories, an arc shaped trajectory that composed of 58 points and a linear trajectory divided into 29 points. The obtained results revealed that the proposed method can be used successfully in solving the inverse kinematic problem of the designed mechanism

Design and finite element analysis of MEMS based electrothermal micro-actuator

Bu makale, COMSOL yazılımı ile tasarlanan mikro elektromekanik sistem (MEMS) tabanlı elektrotermal mikro-aktüatörün sonlu elemanlar analizi çalışmasını sunmaktadır. Elektrotermal aktüatörler, elektrostatik aktüatörlere kıyasla daha büyük yer değiştirmeler sağlamaktadır. Termal aktüatörler iki tiptir. Bimorf termal aktüatör ve tek malzemeden yapılmış elektrotermal uyumlu (ETU) aktüatör. Bimorf aktüatörler, iki veya daha fazla farklı malzemeden yapılmış kompozit yapıdır. Bu çalışmada ETU tipi termal aktüatör kullanılmıştır. İki yönde hareket edebilen mikro-aktüatör, belirlenen kriterlere göre tasarlanmış ve analizler gerçekleştirilmiştir. Sonlu elemanlar analizi için mikro-aktüatöre iletken özelliği olan polycrystalline silicon malzeme ataması yapılmıştır. Bu analiz mikro-aktüatörün fabrikasyonu ve karakterizasyonu işlemleri öncesinde büyük öneme sahiptir. Analiz sürecinde gerilim uygulanarak mikro-aktüatörün hareket etmesi sağlanmıştır. Çalışma gerilimi, 1V’luk artışlarla 0V’dan mikro-aktüatörün yapısında kırılmalar ve bozulmalar gözlemlenene kadar artırılmıştır. Mikro-aktüatör 5V gerilime kadar dayanabilmiştir. Bu gerilim değerinden sonra mikro-aktüatörün yapısında kırılmalar ve bozulmalar meydana gelmiştir. Analizler sonucunda maksimum yer değiştirme 5V gerilim uygulandığında 4.18 µm olarak ölçülmüştür. Sonuç olarak, elektrotermal mikro-aktüatör tasarımı çift yönlü olduğundan maksimum yer değiştirme 8.36 µm olarak tespit edilmiştir.This article presents the finite element analysis study of the micro-electromechanical system (MEMS) based electrothermal micro-actuator designed with COMSOL software. Electrothermal actuators provide larger displacements compared to electrostatic actuators. Thermal actuators are of two types. Bimorph thermal actuator and electrothermal compatible (ETU) actuator made of single material. Bimorph actuators are composite structures made of two or more different materials. In this study, ETU type thermal actuator was used. The micro-actuator, which can move in two directions, has been designed and analyzed according to the specified criteria. Polycrystalline silicon material is assigned to the micro-actuator for finite element analysis. which has a conductive feature. This analysis is of great importance before the fabrication and characterization processes of the micro-actuator. During the analysis process, the micro-actuator was moved by applying voltage. The operating voltage is increased from 0V in 1V increments until breaks and distortions are observed in the structure of the micro-actuator. The micro-actuator was able to withstand up to 5V voltage. After this voltage value, breaks and distortions occurred in the structure of the micro-actuator. As a result of the analyzes, the maximum displacement was measured as 4.18 µm when 5V voltage was applied. As the electrothermal microactuator design is bidirectional, the maximum displacement was determined to be 8.36 µm

Trajectory Planning of a 5-DOF Serial Robot Manipulator in Joint-Space

Bu çalışmada eğitim amaçlı kullanılmak üzere dönel eklemlere sahip 5 Serbestlik Dereceli (SD) bir seri robot manipülatörü gerçekleştirilmiştir. Robot 150 gr taşıma kapasiteli ve eklem hareketleri rahat, sürtünmesiz ve titreşimsiz olarak hareket edebilmesine imkân sağlayacak özelliklerde,radyo kontrollü R/C Servo motorlar kullanılmıştır. Eklem uzayında yörünge planlaması yapabilmek için robotun ters kinematik problemi çözülmüş ve yörünge planlaması üçüncü dereceden bir polinom kullanılarak gerçekleştirilmiştir. Tasarlanan 5 eksenli manipülatörün kullanıcı tarafından rahat ve basit bir şekilde kullanılması amacıyla Visual BASIC programında görsel bir arayüz hazırlanmıştır. Son olarak geliştirilen mekanizmanın öğrenciler tarafından yapılan robotlarla ilgili uygulamalarda başarıyla kullanıldığı gözlemlenmiştirIn this study, a five Degrees of Freedom (DOF) serial robot manipulator with revolute joints was designed and realized to be used for educational purposes. The robot has 150 gr payload and the motions of the joints were provided by using radio controlled R/C servo motors with smooth and vibration-free movement. In order to perform the trajectory planning in the joint space the inverse kinematics problem of the robot was solved and a third order polynomial was used for the trajectory planning. So as to present a simple and efficient way to the user for controlling the robot, a visual user interface was also designed by utilizing Visual Basic Programming Language. Finally, it was observed that the designed mechanism has been successfully used by the students for the projects involving robots