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Öğe 3D Printed Capacitive Pressure Sensor with Corrugated Surface(IEEE, 2017) Tuna, Ahmet; Erden, Oguz K.; Gokdel, Y. Daghan; Sarioglu, BaykalIn this work a novel 3D printed capacitive pressure sensor with a corrugated surface is presented. The design composed of top and bottom plates. The sensor is 3D printed using a commercially available polymer material and then coated with Cr and Au with sputtering process. The dimensions of produced structure that designed is 11x11x4.6mm(3). Due to the corrugated surface, the area of the plates is increased 19.46% compared to a standard flat surface parallel plate capacitive sensor in the same bulk area. The design process of the sensor, simulation and the experimental results are given and explained in detail. The performance of the sensor is tested with various pressure levels between 0 Pa and 8.88 kPa. The experimental results show that the capacitance range of the sensor is 2.7 pF-4.3 pF. The maximum sensitivity of the sensor is obtained as 0.14 pF / kPa. The results confirm that the presented capacitive sensor can be utilized for carrying out pressure measurements.Öğe Design and Implementation of a Low-Cost High-Performance Syringe Pump System(IEEE, 2017) Coskun, Hilmi; Gul, Ozgur; Ferhanoglu, Onur; Gokdel, Y. DaghanThis study describes design and implementation of a high-performance, low-cost, syringe pump device. Proposed device can be used with different injectors having volumes that are ranging from a common 0.5 mL to a larger 60 mL. This adaptable and programmable syringe pump provides high accuracy and adjustable flow rate in a simple mechanical manner and costs approximately $ 200. Developed system was tested on an optical table in lab conditions. It is measured that system can provide rates up to 0.05 mL/ h, when used on a 0.5 mL syringe whereas the maximum volume 60 mL injector can provide a flow rate of 5.8 mL/ h. Mean flow rate error of the system is calculated as 1.33%. Time-distance plots reveal a high degree of linearity and negligible hysteresis. Thus, the manufactured syringe pump is an excellent candidate as a high-precision liquid delivery system for low-resource settings.Öğe Development of Automated Laser Scanning System for Structural Health Monitoring of Wind Turbines(IEEE, 2017) Dilek, A. Ugur; Oguz, Ali D.; Gokdel, Y. Daghan; Ozbek, MuammerIn recent years, the growing interest and demand in wind energy requires developing new wind turbines with larger size and capacity. However, this situation also causes some new and challenging problems which have not been encountered before in design, operation and maintenance. Strong winds and severe environmental factors can cause cracks and damage on several turbine components such as blades and tower. Determination of the location and extent of this damage at early stages is essential to ensure safe and efficient operation of the turbine. This work aims at developing a new motorized laser Doppler scanning system which can rotate about two axes freely. This new device will enable structural dynamics of the turbine to be monitored remotely by using optical measurement techniques. The developed laser system will be used to take vibration measurements on the structure regularly. The acquired measurements will be compared with the reference measurements taken on the undamaged structure and be used to detect possible damage on the turbine while turbine is parked.Öğe A disposable MEMS biosensor for aflatoxin M1 molecule detection(Elsevier Science Sa, 2022) Erdil, Kuter; Akcan, O. Gokalp; Gul, Ozguer; Gokdel, Y. DaghanIn this work, a paper-based perforated disposable biosensing device is proposed as an alternative method for aflatoxin M1 molecule detection. The demonstrated system is designed to achieve a quick and novel biosensing operation with low-cost materials using competitive assay method. For that purpose, the main fabrication material has opted as a 190 izm thick filter paper. 50 izm thick piezoresistive graphite paste is coated onto both sides of the paper-based cantilever beam with the aim of acquiring more sensitive magnetic nanoparticle weight sensing capability. Additionally, the structure has arrays of closely spaced perforations to augmented effective Young's modulus of the cantilever beam and further increase the system's sensitivity. An electrocoil positioned 1 mm below the sensor tip to apply an H(ext )and magnetically increase weight of the aflatoxin M1 with bovine serum albumin compound. An electronic read-out circuitry is implemented and integrated into the system. Average values of sensitivity and limit of detection (LoD) for each detection approach were calculated without blank subtraction and are shown with the standard error of the mean (SEM). LoD is calculated as 4.63 izg AFM1 which corresponds to 0.20127 V/V after subtracting standard deviation from the average value. It is experimentally demonstrated that the proposed system can detect a minimum of 14 izg of AFM1 molecules (0.14155 V/V). We magnetically amplified this tiny fragment of targeted molecules approximately 2731 times to 38.237 mg and made it detectable even with a disposable system. The sensitivity of the proposed system is 45.953 izV/mg. Finally, the maximum detectable AFM1 weight is reported as 71 izg.Öğe Embedded System Design and Implementation For a Miniaturized Laser Projection Display(IEEE, 2019) Kucuk, Elif; Arseven, Aysin; Sarioglu, Baykal; Gokdel, Y. DaghanIn this work, a low power compact embedded system for steel scanner based miniaturized projection displays is presented. The proposed system is composed of a steel micro scanner, a microcontroller unit, a power amplifier, a 5mW laser with 650nm wavelength and a transistor-based laser driver. The proposed embedded system generates two actuation signals for vertical and horizontal movements of the scanner. The embedded system also generates laser pulses in synchronization with the actuation signals to form a stable and undistorted image. The steel scanner's total optical scanning angles (TOSA) are 5.415 and 3.2729 in slow-scan and fast-scan directions, respectively. Slow scan frequency is 264 Hz, while the fast scan frequency is 2640 Hz. The proposed device can deliver sufficient torque to allow non-resonant operation. Sample images generated using the proposed system are also given.Öğe Flexible Linear Absolute Encoder System for Force Localization in Soft Environments(IEEE, 2020) Erdil, Kuter; Korkut, Dogukan; Akcan, O. Gokalp; Muslu, Batin; Gokdel, Y. Daghan; Baran, Eray A.This paper proposes a novel disposable linear absolute encoder system and its peripheral electronic readout circuitry to be used for the localization of force in a continuum media such as a flexible robotic arm. The proposed structure relies on the design of graphite layers on a flexible surface that shows varying resistance based on the applied strain. The proposed topology can localize the force applied on a continuous paper based sensor having the geometry of an absolute encoder system. The successful results obtained from the experiments prove the efficacy of the proposed system while opening new paradigms for the possibility of contact force localization in flexible structures like soft robots.Öğe Image denoising using 2-D wavelet algorithm for Gaussian-corrupted confocal microscopy images(Elsevier Sci Ltd, 2019) Gokdag, Yunus Engin; Sansal, Firat; Gokdel, Y. DaghanConfocal laser scanning microscopy (CLSM) imaging is a non-invasive optical imaging technique for the examination of the living tissues. CLSM inherently enables in-depth sectioning (z-slices) of the focused specimen. Z-slices of the targeted tissue are gathered by adjusting the focal point on the z-axis into the tissue. Unfortunately, these images can get corrupted with noise of different levels caused by out-of focus light originating from above and below the focal plane. This study proposes a reliable method to indicate and eliminate the additive white Gaussian noise (AWGN) present in real CLSM images of skin tissue. In this work, a denoising algorithm using discrete wavelet transform (DWT) is developed in order to remove the noise by preserving the energy conservation. The effect and performance of different wavelet thresholding algorithms are compared and studied along with different tuning parameters. The selection of components employed in the algorithm affects the noise reduction performance therefore, a systematic approach is presented to obtain and utilize the best combination of these parameter values. Analysis of variance (ANOVA) is exploited to inspect the main and the interaction effects of treated parameters. Computational results show the effectiveness of the methodical tuning approach to CLSM image denoising. (C) 2019 Published by Elsevier Ltd.Öğe Paper-Based Piezoresistive Force Encoder for Soft Robotic Applications(IEEE-Inst Electrical Electronics Engineers Inc, 2022) Akcan, Omer Gokalp; Erdil, Kuter; Korkut, Dogukan; Baran, Eray A.; Gokdel, Y. DaghanThis work demonstrates the design, implementation, and experimental results of a low-cost disposable flexible sensor system capable of both impact localization and measurement. The proposed flexible sensor structure utilizes a special series of Bristol paper as the main fabrication material, which is coated with electric paint graphite paste and silver paste. The implemented sensor system uses a planar absolute encoder-like sensing topology to locate the impact and has a low-cost and quick manufacturing process. The size of the structure is 210 x 18.56 mm with a thickness of approximately 340 mu m. It has an electronic read-out consisting of three identical Wheatstone bridge circuits and instrumentation amplifiers for each bit. It can detect the external forces in the range of 0.6N to 12N with a spatial resolution of 2.4 cm and 0.55 cm in horizontal and vertical axes, respectively. The proposed sensor structure is tested in a series of experiments using a robotic setup consisted of a pantograph mechanism and a direct drive linear motor. The experiments illustrate the results with measurement sensitivity as small as 1N and proper fatigue resilience against repetitive loads.Öğe Perforated Paper-Based Piezoresistive Force Sensor(IEEE, 2019) Erdil, Kuter; Ayrac, Tugce; Akcan, O. Gokalp; Gokdel, Y. DaghanIn this work, a paper-based disposable piezoresistive force sensor has been designed, fabricated and tested along with peripheral electronic circuit. Strathmore (R) 400 series Bristol paper is employed as the substrate and it is coated with graphite and silver ink to form a perforated cantilever beam which constitutes the sensor part of the force sensing system. The proposed force sensing system can measure a force ranging to 24 mN with a force resolution of 196 mu N. The implemented sensor has a sensitivity of 8.63 mV/mN.Öğe A Read-Out System for Disposable Paper-Based Sensors(IEEE, 2018) Ayrac, Tugce; Gokdel, Y. DaghanThis study presents design, implementation and test of a read-out system for disposable paper-based sensors. Proposed system basically consists of a Strathmore (R) 300 series Bristol paper-based cantilever with the dimension of lem x 3.5cra and the thickness of roughly 400/art which is covered with a thin piezoresistive layer and a read-out circuitry that is composed of a Wheatstone Bridge circuit and instrumentation amplifier (INA128). Proposed read-out system is simulated, implemented and tested. The sensitivity of the proposed read-out system is measured as 0.25m/V/mu m and Delta V-out and 1.5m Omega/mu m for Delta R-PR.Öğe Reliability Testing of 3D-Printed Electromechanical Scanning Devices(Springer, 2018) Gonultas, B. Mert; Savas, Janset; Khayatzadeh, Ramin; Aygun, Sacid; Civitci, Fehmi; Gokdel, Y. Daghan; Berke Yelten, M.Recent advances in the field of stereolithography based manufacturing, have led to a number of 3D-printed sensor and actuator devices, as a cost-effective and low fabrication complexity alternative to micro-electro-mechanical counterparts. Yet the reliability of such 3D-printed dynamic structures have yet to be explored. Here we perform reliability tests and analysis of a selected 3D-printed actuator, namely an electromechanical scanner. The scanner is targeted towards scanning incoming light onto the target, which is particularly useful for barcoding, display, and opto-medical tissue imaging applications. We monitor the deviations in the fundamental mechanical resonance, scan-line, and the quality factor on a number of scanners having different device thicknesses, for a total duration of 5 days (corresponding to 20-80 million cycles, depending on the device operating frequency). A total of 9 scanning devices, having 10 mm x 10 mm die size were tested, with a highlight on device-device variability, as well as the effect of device thickness itself. An average standard deviation of < similar to%10 (with respect to the mean) was observed for all tested parameters among scanners of the same type (an indicator device to device variability), while an average standard deviation of less than about 10 percent (with respect to the mean) was observed for all parameters for the duration of the entire test (as an indicator of device reliability), for a total optical scan angle of 5 degrees.Öğe Silicone Mold Implementation for High-Sensitive Detection of Strain Sensing using Paper-Based Piezoresistive System(IEEE, 2020) Korkut, Dogukan; Erdi, Kuter; Akcan, O. Gokalp; Muslu, Batin; Baran, Eray A.; Gokdel, Y. DaghanThis paper presents the design, fabrication, experimental results and related discussion of a portable bending enhancing silicone mold structure for biomedical applications in which a high-sensitive but low-cost force measurement structure with a large-dynamic range is required. Proposed system is composed of a replaceable parts like graphite coated Strathmore (R) 400 series Bristol paper and cheap RTV-2 silicone molds. The results shows that low-cost, portable and high-sensitive force and strain sensor systems can be realized for point-of-care biomedical applications in the future.
