Mohd Rosydi Zakaria
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Preferred name
Mohd Rosydi Zakaria
Official Name
Mohd Rosydi , Zakaria
Alternative Name
Zakaria, M. R.
Main Affiliation
Scopus Author ID
55603578400
Researcher ID
EIP-2267-2022

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Modification of surface acoustic wave (SAW) sensor using zinc oxide nanowires

2018-11 , Mohd Rosydi Zakaria , Siti Fatimah Abd Rahman , S. L Leng , M. H. Mat , Uda Hashim

The limitation and complexity of current available biosensor to detect nano-scale organism has introduce an idea to develop simple, high sensitivity and performance biosensor. Surface acoustic wave (SAW) device which widely used in telecommunication field had been remodeled as biosensor which able to detect the microorganism in aqueous state. Zinc oxide (ZnO) nanowires with high crystalline structure were prepared on the sensing area of SAW device through a low-cost sol-gel method coupled with a hydrothermal process. The ZnO nanowires were proposed as an effective strategy to enhance the shift frequency of the sensing device. Lift-off technique was used to develop the aluminum IDTs structure on the piezoelectric substrate. X-ray diffraction (XRD) and Scanning electron microscope (SEM) were used to study the crystal lattice orientation and physical properties of ZnO nanowires. The electrical test and frequency response were conducted to characterize the functionality of the fabricated device.

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Characterization of Zinc Oxide (ZnO) piezoelectric properties for Surface Acoustic Wave (SAW) device

2017-11-22 , Mohd Rosydi Zakaria , Shazlina Johari , Mohd Hafiz Ismail , Uda Hashim

In fabricating Surface Acoustic Wave (SAW) biosensors device, the substrate is one of important factors that affected to performance device. there are many types of piezoelectric substrate in the markets and the cheapest is zinc Oxide substrate. Zinc Oxide (ZnO) with its unique properties can be used as piezoelectric substrate along with SAW devices for detection of DNA in this research. In this project, ZnO thin film is deposited onto silicon oxide substrate using electron beam evaporation (E-beam) and Sol-Gel technique. Different material structure is used to compare the roughness and best piezoelectric substrate of ZnO thin film. Two different structures of ZnO target which are pellet and granular are used for e-beam deposition and one sol-gel liquid were synthesize and compared. Parameter for thickness of ZnO e-beam deposition is fixed to a 0.1kÅ for both materials structure and sol-gel was coat using spin coat technique. After the process is done, samples are annealed at temperature of 500°C for 2 hours. The structural properties of effect of post annealing using different material structure of ZnO are studied using Atomic Force Microscopic (AFM) for surface morphology and X-ray Diffraction (XRD) for phase structure.

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A study of Fowler-Nordheim injection mechanism for engineered tunnel barrier flash memory devices

2011 , Mohd Rosydi Zakaria

Flash memory is a device that is used as a tool to store data electrically. The main advantage of this device is in the non-volatility which can store data without power supply, thus make the device very popular in broad application. Conventional Flash memory generally uses single tunnel oxide with a thickness of 7 nm to 10 nm as a tunnel barrier. In order to obtain good device performance, the thickness of the tunnel barrier must be reduced. If the thickness of the oxide is reduced below than 5 nm, device performance will be better but suffer from problems such as current leakage and data retention. To overcome this problem, a technique identified as Engineered Tunnel Barrier is used to replace the single oxide used in conventional flash memory. The study includes mathematical calculation and computer simulation investigating the device performance criteria such as programming speed, programming tunneling current and programming voltage. The Fowler-Nordheim model is used for mathematical analysis while Technology Computer Aided Designing (TCAD) tool is used for simulating the flash memory device. From both studies, result shows that the performance of the device improve significantly after the engineered tunnel barrier is applied to replace conventional technique Results from this study showed that by using the engineered tunnel barrier techniques the device performance such as programming speed, programming tunneling and programming voltage have increased by 1 )..lS, le1 A/Cm and 12V compared to conventional flash memory that is 1 ms, 1 e·2 A/Cm, and 17V, respectively. From the result, it can be concluded that the Engineered Tunnel Barrier Flash Memory is very promising candidate for the next generation Flash Memory product.

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Characterization of Zinc Oxide (ZnO) piezoelectric properties for Surface Acoustic Wave (SAW) device

2017 , Mohd Rosydi Zakaria , Shazlina Johari , Mohd Hafiz Ismail , Uda Hashim

In fabricating Surface Acoustic Wave (SAW) biosensors device, the substrate is one of important factors that affected to performance device. there are many types of piezoelectric substrate in the markets and the cheapest is zinc Oxide substrate. Zinc Oxide (ZnO) with its unique properties can be used as piezoelectric substrate along with SAW devices for detection of DNA in this research. In this project, ZnO thin film is deposited onto silicon oxide substrate using electron beam evaporation (E-beam) and Sol-Gel technique. Different material structure is used to compare the roughness and best piezoelectric substrate of ZnO thin film. Two different structures of ZnO target which are pellet and granular are used for e-beam deposition and one sol-gel liquid were synthesize and compared. Parameter for thickness of ZnO e-beam deposition is fixed to a 0.1kÅ for both materials structure and sol-gel was coat using spin coat technique. After the process is done, samples are annealed at temperature of 500°C for 2 hours. The structural properties of effect of post annealing using different material structure of ZnO are studied using Atomic Force Microscopic (AFM) for surface morphology and X-ray Diffraction (XRD) for phase structure.

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A Numerical Study of Collective Cell Migration in a Microchannel Driven by Surface Acoustic Wave (SAW) Device

2023-01-01 , Mazlee Mazalan , Anas Mohd Noor , Yufridin Wahab , Shazlina Johari , Mohd Rosydi Zakaria , Zaman W.S.W.K.

Collective cell migration is involved in a variety of biological contexts, including tissue morphogenesis, wound healing, and cancer invasion. Many studies have revealed that chemical, mechanical, and electrical stimulation all affect cell migration. Although an acoustic stimulus has been shown to influence cell migration in the past, the underlying mechanism is still unknown. A computational model that accounts for acoustic-structure interaction was constructed in this study to simulate the formation of a surface acoustic wave (SAW) field and the application of the acoustic pressure field on collective cell migration. A group of cells within a microchannel device and two ports of interdigitated transducers (IDTs) with different wavelengths were modeled. The stresses within cells were investigated as it was influenced by substrate displacement and pressure acoustic in the cell media generated by the SAW device. As a result, we observed the local stress within cells near the solid-fluid interfaces. For propagating SAW, the shorter wavelength of IDTs (600 μm) attributed to high stress at the cell's top and bottom as compared to the SAW device with the longer wavelength (1000 μm). The standing SAW occurred underneath collective cells. The results of standing SAW on cell stress at the bottom confirm that the SAW device can be useful to regulate the abnormalities cellular activities associated with cell migration.

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Hydrothermal growth of titania nanowires for SAW device sensing area

2017 , Mohd Rosydi Zakaria , Sh.Nadzirah S. Ayub , Mohd Hafiz Ismail , Shazlina Johari , Uda Hashim

Synthesis of titania or titanium dioxide (TiO 2) is attracted to energy and environmental applications. Here, the growth of nanostructure TiO 2 nanowires on Si (100) substrates by using the two-step method. Different seed layers of TiO 2 were deposited by spin coating and annealing, followed by the growth of TiO 2 nanowires by using the hydrothermal method. The sol-gel technique was used in preparing the TiO 2 solution for the thin film deposition purpose. Acetic acid, hydrochloric acid and tris (2-aminoethyl) amine were used as a stabilizer to synthesize three different TiO 2 seed layers. The aim of this study was to understand the role of polycrystalline size on thin film towards the diameter of nanowires grown as a sensing area in Surface Acoustic Wave (SAW) Biosensor. The morphology and structure of the thin film and TiO 2 nanowires were characterized using X-Ray diffraction (XRD), scanning electron microscope (SEM), field emission scanning electron microscope (FESEM) and atomic force microscopy (AFM).

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