15 research outputs found

    DESIGN AND MICROFABRICATION OF A CMOS-MEMS PIEZORESISTIVE ACCELEROMETER AND A NANO-NEWTON FORCE SENSOR

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    DESIGN AND MICROFABRICATION OF A CMOS-MEMS PIEZORESISTIVE ACCELEROMETER AND A NANO-NEWTON FORCE SENSOR by Mohd Haris Md Khir Adviser: Hongwei Qu, Ph.D. This thesis work consists of three aspects of research efforts: I. Design, fabrication, and characterization of a CMOS-MEMS piezoresistive accelerometer 2. Design, fabrication, and characterization of a CMOS-MEMS nano-Newton force sensor 3. Observer-based controller design of a nano-Newton force sensor actuator system A low-cost, high-sensitivity CMOS-MEMS piezoresistive accelerometer with large proof mass has been fabricated. Inherent CMOS polysilicon thin film was utilized as piezoresistive material and full Wheatstone bridge was constructed through easy wiring allowed by three metal layers in CMOS thin films. The device fabrication process consists of a standard CMOS process for sensor configuration and a deep reactive ion etching (DRIE) based post-CMOS microfabrication for MEMS structure release. Bulk single-crystal silicon (SCS) substrate was included in the proof mass to increase sensor sensitivity. Using a low operating power of 1.67 m W, the sensitivity was measured as 30.7 mV/g after amplification and 0.077 mV/g prior to amplification. With a total noise floor of 1.03 mg!-!Hz, the minimum detectable acceleration is found to be 32.0 mg for a bandwidth of I kHz which is sufficient for many applications. The second device investigated in this thesis work is a CMOS-MEMS capacitive force sensor capable ofnano-Newton out-of-plane force measurement. Sidewall and fringe capacitance formed by the multiple CMOS metal layers were utilized and fully differential sensing was enabled by common-centroid wiring of the sensing capacitors. Single-crystal silicon (SCS) is incorporated in the entire sensing element for robust structures and reliable sensor deployment in force measurement. A sensitivity of 8 m V /g prior to amplification was observed. With a total noise floor of 0.63 mg!-IHz, the minimum detection acceleration is found to be 19.8 mg, which is equivalent to a sensing force of 449 nN. This work also addresses the design and simulation of an observer-based nonlinear controller employed in a CMOS-MEMS nano-Newton force sensor actuator system. Measurement errors occur when there are in-plane movements of the probe tip; these errors can be controlled by the actuators incorporated within the sensor. Observerbased controller is necessitated in real-world control applications where not all the state variables are accessible for on-line measurements. V

    Sistem Kontrol Lengan Robot Menggunakan Rekaman Gerakan

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    Keberadaan teknologi robotika pada saat ini sangat membantu aktivitas manusia untuk mempermudah melakukan perkerjaan.Salah satu teknologi robotika saat ini yaitu lengan robot.Lengan robot merupakan jenis robot yang menyerupai lengan manusia yang dapat memindahkan suatu barang dari satu tempat ke tempat lainnya. Namun ketika lengan robot akan digunakan untuk mengangkat sesuatu maka dibutuhkan perhitungan yang khusus agar barang dapat berpindah tempat, maka lengan robot tersebut harus dilengkapi sistem rekaman gerakan agar dapat terkendali sesuai keinginan. Penelitian ini bertujuan untuk merancang lengan robot yang memiliki 6 derajat kebebasan dan mampu merekam gerakan yang sudahdikerjakannya secara terus menerus dengan menentukan kepresisian maksimum dan nilai waktu tunda. Lengan robot dirancang menggunakan mikrokontroler ATMEGA 2560 dimana mikrokontroler tersebut sudah memiliki fitur yang langsung berhubungan dengan pengendali motor stepper. Lengan robot memiliki enam buah motor stepper untuk menggerakkan masing-masing sumbu berdasarkan enam bagian yaitu; putaran dasar, siku, bahu, putaran pergelangan tangan, pergelangan serta sebagai end-effectors adalah penggenggam. Hasil penelitian menunjukkan bahwa lengan robot mampu merekam jejak gerakan dengan jangkauan maksimum pergerakan robot sejauh 30 cm dengan nilai rata-rata maksimum SWP (Waktu Sikap Perjalanan) 18.08 detik dan LP (Latensi Penggerak) dengan nilai maksimum yaitu 20.21 detik. Untuk nilai KP (keakuratan peletakan) dengan perpindahan maksimum untuk semua percobaan memiliki nilai sebesar 0.35 cm dan PP (Kemampuan Posisi Pengulangan) yang paling besar nilai 0.41 cm

    Printed Circuit Board Fault Inspection Based on Eddy Current Testing Using Planar Coil Sensor

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    Abstract This paper presents a printed circuit board (PCB) fault inspection method using eddy current testing generated from Helmholtz coils with a planar array-coil sensor to locate and inspect short and open faults on uniformly spaced interconnect single layer PCBs. The differences between the induced voltages from fault-free boards and faulty boards will be recorded in tables and translated into contour plots. The experimental results showed that in the presence of a short fault, the differences between the induced voltages from fault-free and faulty boards are highly negative. However, in the presence of an open fault, the differences between the induced voltages from fault free and faulty boards are highly positive. These highly positive or negative induced voltages can be translated into high density color regions on contour plots. The potential fault positions can be located by observing the color regions of the contour plots with respect to each element of the matrix sensor

    2-D Modes Analysis of Micro-Ring Resonator:In case of chemical vapor sensing

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    This paper describes 2-D modes analysis on the waveguide structure. Micro - Ring Resonator formation was simulated to able the chemical vapor detection by using COMSOL Multiphysics application. We present the simulation of mode analysis from a Micro-ring Resonator as sensing the chemical vapor. By implementing the device parameters. We have seen from the simulator that the optical mode is handled equally within the ring. Using the variation of effective refractive index, our simulator result of ring resonator generated the mode analysis in two-dimension perspective. We conclude that the ring resonator device has potential for generating the certain wavelength

    A Low-Cost CMOS-MEMS Piezoresistive Accelerometer with Large Proof Mass

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    This paper reports a low-cost, high-sensitivity CMOS-MEMS piezoresistive accelerometer with large proof mass. In the device fabricated using ON Semiconductor 0.5 μm CMOS technology, an inherent CMOS polysilicon thin film is utilized as the piezoresistive sensing material. A full Wheatstone bridge was constructed through easy wiring allowed by the three metal layers in the 0.5 μm CMOS technology. The device fabrication process consisted of a standard CMOS process for sensor configuration, and a deep reactive ion etching (DRIE) based post-CMOS microfabrication for MEMS structure release. A bulk single-crystal silicon (SCS) substrate is included in the proof mass to increase sensor sensitivity. In device design and analysis, the self heating of the polysilicon piezoresistors and its effect to the sensor performance is also discussed. With a low operating power of 1.5 mW, the accelerometer demonstrates a sensitivity of 0.077 mV/g prior to any amplification. Dynamic tests have been conducted with a high-end commercial calibrating accelerometer as reference

    Optoelectronic Characterization and Properties of Single-walled Carbon Nanotubes in a Liquid Dispersion Form

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    Carbon nanotubes (CNTs) are very promising nanodevices due to their extraordinary electrical, thermal, and optical properties. However, as-grown single-walled CNTs (SWCNTs) contain a mixture of semiconducting and metallic species with great features versatility and variation. Solution-based processing of this nanomaterial is vital for further implementation in applicable platforms. In this paper, important optoelectronic intrinsic properties of SWCNTs in dispersions are studied applying a semi-empirical approach of optical characterization and Tauc/Davis-Mott relation and Max-Planck equations. SWCNTs are found to have a direct bandgap of 2.20 eV, an indirect bandgap of 0.27 eV, an optical conductivity of about 107 S cm-1, and exhibited a metamaterial behavior ascribed to the high negative permittivity. In addition, the optimum parameters for the dispersion of SWCNTs, and the separation of the semiconducting species using simple mechanical methods of ultrasonication and density gradient ultracentrifugation, respectively, without using surfactants are also presented

    Pengaruh Getaran dan Kecepatan Cetak pada Konstruksi Rangka 3D-Printer

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    3D printing is the process of making three-dimensional (3D) solid objects from a digital design at a relatively low cost in a short span of time. Basically it is not much different from ordinary printing tools, it's just the resulting output in the form of 3D. The purpose of this study is to determine the prototype product design results from the design of the 3D printing frame design on the effect of vibrations produced by the stepper motor to get to the precision on the object / design, vibrations generated from mechanical or speed when the 3d printer is performing its tasks can lead to less precision results of products made with actual results. The technique used in the 3d printing machine is the FDM (Fused Deposition Modeling) technique which is commonly used in 3D Printing technology because it only requires a lower cost compared to other techniques, the material used for various PLA (polylatic acid) experiments with various types kinds of combinations of products produced, the method used in this study, the experimental method by referring to the parameter settings of Ultimaker Cura 4.2.0 3D printing slincing software with settings such as, nozzle temperature, bed temperature, print speed, extruder speed and thin thickness of material per layer (layer height). Based on the results of experiments and measurements, it will determine the parameters that produce the printed object that has the highest level of precision. With this research it is hoped that 3D Printing activists can help improve the precision of the products.3D printing adalah proses pembuatan benda padat tiga dimensi (3D) dari suatu desain digital dengan biaya yang relatif rendah dalam rentang waktu yang singkat. Pada dasarnya memang tidak jauh berbeda dari alat printing biasa, hanya saja output yang dihasilkan berupa 3D. Tujuan penelitian ini adalah untuk mengetahui hasil desain produk prototype dari perancangan desain rangka 3D printing terhadap pengaruh getaran yang dihasilkan oleh motor stepper untuk mendapatkan ke presisian pada objek/design, getaran yang dihasilkan dari mekanik atau kecepatan pada saat 3d printer menjalankan tugasnya dapat mengakibatkan kurang presisi hasil produk yang dibuat dengan hasil yang sebenarnya. Teknik yang digunakan pada mesin 3d printing yaitu teknik FDM (Fused Deposition Modelling) merupakan metode yang umum digunakan pada teknologi 3D Printing karena hanya membutuhkan biaya yang lebih murah dibandingkan dengan teknik yang lain, bahan yang digunakan untuk eksperimen berjenis PLA (polylatic acid) dengan berbagai macam kombinasi produk yang dihasilkan,Metode yang digunakan pada penelitian ini, yaitu metode eksperimental dengan mengacu pada pengaturan parameter dari software slincing 3D printing Ultimaker Cura 4.2.0 dengan pengaturan seperti, suhu nozzle, suhu bed, kecepatan cetak,kecepatan extruder dan tebal tipis material per layer (layer height). Berdasarkan hasil eksperimen dan pengukuran maka akan ditentukanlah parameter yang menghasilkan objek cetak yang memiliki tingkat ke presisian paling baik

    The Determination of Dawn Time through Image Processing Camera

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    Determining the early time prayer is very fundamental for Muslims as it directly relates to the legal requirements of prayer. Prayers are not performed whenever we want, but rather there is a determination of the beginning and end of the prayer time as a guideline for Muslims to carry it out. The Indonesia government sets standards for Muslims to perform the dawn prayer service, by precisely determining the degree of the emergence of the dawn of Sadiq by -200. This study aims to compare the determination of the government's dawn time using different sensors, specifically drone cameras as image sensors. Drones were chosen due to their several advantages. The data generated by the drone is in the form of photos, which are subsequently processed using digital image processing software, called image-J. The data obtained are in the form of mean and standard deviation. All data collected in 1 day is recorded using Excel to form a graph of data which is then carried out by a polynomial approach to find out the cutoff point as the beginning of the dawn of Sadiq which indicates the start of dawn. The method used in this research is using the 4th order polynomial approach and the Sarrus method and the data obtained is the mean value and standard deviation. The conclusions obtained in the image analysis research are that the government's dawn time is 15 minutes too fast, the standard obtained in this study is -14.98° and unlike 2D SQM data, 3D drone data results in more accurate data analysis
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