Browsing by Author "Kafumbe, Said"

Now showing 1 - 6 of 6
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    Driver Awareness System Using RFID Technology: A collaboration in Senior Design Projects
    (IEOM Society International, 2018) Abd-Elrady, Emad; Abuelkheir, Osama; Kafumbe, Said
    Road traffic safety refers to the methods and measures used to prevent road users from being killed or seriously injured. Typical road users include: pedestrians and vehicle passengers. A collaboration work with a Telecommunication industrial partner in senior design graduation projects considers enhancing road safety. In this work, Radio Frequency Identification (RFID) technology is used in order to develop driver awareness systems against pedestrian crossing, foggy weather collisions, construction road site, and bridge crash. This paper will focus on the awareness system developed against pedestrian crossing.
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    iRovers: Real-time Unmanned Four-wheel Iot Vehicles for Air and Noise Pollution Monitoring
    (IEEE., 2018) Kafumbe, Said
    Knowing the exact amounts of hazardous gases as well as the noise levels in an indoor setting is vital for a healthy green community. With most people in communities spending time indoor, the quality of the air indoor, as well as the noise levels there play an important role in the health life style of the occupants. Additionally, with the number of road users increasing, as well as with more industries growing, the level of gas emissions into the environment increase. This prompts the need for fully autonomous systems that can move uncontrolled through various places to detect the levels of dangerous gas emissions, the noise levels, and thus monitor the overall air and noise quality for future clean and smart green societies. Work done in the development of mobile robots that can autonomously move around avoiding obstacles and reaching several areas of an indoor setting monitoring the air and noise quality is presented.
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    Operational Process for Manufacturing a MEMS Micro-Cantilever System
    (IEEE, 2015) Kafumbe, Said; Ravichandran, Danthakani; Emad, Abd-Elrady; Mohammad, Alqudah; Alun, Harris; Jim, Burdess
    The processing techniques and materials utilized in the fabrication of a two-terminal electrostatically actuated micro electro-mechanical (MEMS) cantilever-arrayed device used for radio frequency tuning applications are presented in this work. The process is based on silicon surface micromachining with spin-coated photoresist as the sacrificial layer placed underneath the electroplated gold structural material and an insulating layer of silicon dioxide. Silicon dioxide layer is deposited using plasma enhanced chemical vapour deposition (PECVD), to avoid a short circuit between the cantilever and the bottom electrode. The fabrication process involves six major steps designed under controlled experiments. These includes the plasma enhanced chemical vapour deposition of the silicon dioxide insulating layer, optical lithography to transfer photomask layer patterns, vacuum evaporation to deposit thin films of Titanium (Ti) and Gold (Au), electroplating of Au, the dry release of the cantilever beam arrays, and finally the wafer dicing to split the different micro devices. These process steps were each sub-detailed to give a total of fourteen micro-fabrication processes. Scanning electron microscope (SEM) images taken on the final fabricated device that was dry released using oxygen plasma ashing to avoid stiction, showed twelve freely suspended micro-cantilevered beams suspended with an average electrostatic gap of 2.29±0.17 microns above a 4934±3 angstrom thick silicon dioxide layer. Preliminary dimensional measurements on the fabricated devices revealed that the cantilevers were at least 52.06±1.93 microns wide with lengths varying from 377.97±0.01microns to 1491.89±0.01 microns, and were at least 2.21±0.05 microns thick. These results were validated by design values
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    RF Tuning Micro Cantilever Array Design, Modeling, and simulation
    (IEOM Society International, 2018) Kafumbe, Said; Alun Harris, Jim Burdess
    MEMS cantilever arrays can be used as non-destructive alternatives during frequency tuning applications. This is because a small electrostatic voltage applied between the cantilever and the bottom electrode is enough to pull it down. Further perturbations can be used to resonate the beam at a different frequency. However, before such micro cantilevers can be designed and fabricated, analytical and numeric modelling and simulation is helpful in the validation of the concept. This paper presents the modelling and simulation of MEMS cantilevers that are used in frequency tuning applications.
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    Semiconductor Manufacturing Process Optimisation
    (IEEE., 2018) Kafumbe, Said
    In a semiconductor manufacturing process the number of process steps as well as the time taken by each step are vital in determining the yield and volume of the manufactured device. Additionally, the manufacturing recipe used at each process greatly determines the reliability and performance of the finished design. By tweaking the process recipe as well as the process times an optimized manufacturing process can be obtained. This work presents process optimization at both the electroplating, cmp and plasma ashing steps for various semiconductor devices with improved performance for all devices.
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    Testing and Characterization of a MEMS Micro-Cantilever System
    (IEEE., 2016) Kafumbe, Said; Alun, Harris; Jim, Burdess
    The testing and characterization of micro-electro-mechanical systems (MEMS) cantilever arrays of average thickness 2.2 ± 0.04 µm, width 52.06 ± 1.93 µm and lengths varying between 390 - 1490 µm, is presented. A novel optical workstation with combining both a surface profiler and a laser vibrometer, was used for the experimental setup. Both static and dynamic tests were performed in characterizing and evaluating the functionality of the fabricated devices using piezo and electrostatic actuation. The static deflection under electrostatic voltage of 10.2 V and 56.4 V was 150 ± 15 nm, and 760 ± 65 nm respectively for a cantilever of nominal length of 390 µm. The shortest beam of nominal length of 390 µm resonated at 4.417 kHz using an electrostatic actuation mechanism with a 0.01 % discrepancy whereas the longest beam of nominal length of 1490 µm resonated at 316.5 Hz with a 0.03 % discrepancy. However using the piezo actuation, the resonance frequency of the shortest and longest cantilevers was 4.515 kHz and 303.82 kHz respectively. The difference from the predicted values was 0.008 % for the shortest beam, and 0.01% for the longest one. All results showed the beams were functioning perfectly for applications in radio frequency tuning.