Ahmad Anwar Zainuddin

Optimization of printing techniques for electrochemical biosensors

Electrochemical biosensors show great promise for point-of-care applications due to their low cost, portability and compatibility with microfluidics. The miniature size of these sensors provides advantages in terms of sensitivity, specificity and allows them to be mass produced in arrays. The most reliable fabrication technique for these sensors is lithography followed by metal deposition using sputtering or chemical vapor deposition techniques. This technique which is usually done in the cleanroom requires expensive masking followed by deposition. Recently, cheaper printing techniques such as screen-printing and ink-jet printing have become popular due to its low cost, ease of fabrication and mask-less method. In this paper, two different printing techniques namely inkjet and screen printing are demonstrated for an electrochemical biosensor. For ink-jet printing technique, optimization of key printing parameters, such as pulse voltages, drop spacing and waveform setting, in-house temperature and cure ann...

Verification of Quartz Crystal Microbalance Array using Vector Network Analyzer and OpenQCM

Received Jan 15, 2018 Revised Mar 14, 2018 Accepted Mar 30, 2018 Blood veins detection process can be cumbersome for nurses and medical practioners when it comes to special overweight type of patients. This simple routine procedure can lead the process into an extreme calamity for these patients. In this paper, we emphasized on a process for the detection of the vein in real time using the consecrations of Matlab to prevent or at least reduce the number of inescapable calamity for patients during the infusion of a needle by phlebotomy or doctor in everyday lives. Hemoglobin of the blood tissues engrossed the Near Infrared (NIR) illuminated light and Night vision camera is used to capture the scene and enhance the vein pattern clearly using Contrast Limited Adaptive Histogram Equalization (CLAHE) method. This simple approach can successfully also lead to localizing bleeding spots, clots from stroke ... etc among other things.

Black Phosphorus Saturable Absorber for Pulse Generation Using Q-switched Teachnique

Received Dec 04, 2017 Revised Jan 11, 2018 Accepted Apr 15, 2018 Wireless Body Area Networks (WBANs) are fundamental technology in health care that permits the information of a patient’s essential body parameters to be gathered by the sensors. However, the safety and concealment defense of the gathered information is a key uncertain problem. A Hybrid Key Management (HKM) scheme [13] is worked based on Public Key Cryptography (PKC)-authentication scheme. This scheme uses a oneway hash function to construct a Merkle Tree. The PKC method increase the computational complexity and lacking scalability. Additionally, it increases expensive computation, communication costs and delay. To overcome this problem, Robust Security for Protected Health Information by ECC with signature Hash Function in WBAN (RSP) is proposed. The system employs hash-chain based key signature technique to achieve efficient, secure transmission from sensor to user in WBAN. Moreover, Elliptical Curve Cryptography algorithm is used to verifies the authenticate sensor. In addition, it describes the experimental results of the proposed system demonstrate the efficient data communication in a network.A Weblogs contains the history of User Navigation Pattern while user accessing the websites. The user navigation pattern can be analyzed based on the previous user navigation that is stored in weblog. The weblog comprises of various entries like IP address, status code and number of bytes transferred, categories and time stamp. The user interest can be classified based on categories and attributes and it is helpful in identifying user behavior. The aim of the research is to identifying the interested user behavior and not interested user behavior based on classification. The process of identifying user interest, it consists of Modified Span Algorithm and Personalization Algorithm based on the classification algorithm user prediction can be analyzed. The research work explores to analyze user prediction behavior based on user personalization that is captured from weblogs.Wireless Body Area Networks (WBANs) are fundamental technology in health care that permits the information of a patient’s essential body parameters to be gathered by the sensors. However, the safety and concealment defense of the gathered information is a key uncertain problem. A Hybrid Key Management (HKM) scheme [13] is worked based on Public Key Cryptography (PKC)-authentication scheme. This scheme uses a oneway hash function to construct a Merkle Tree. The PKC method increase the computational complexity and lacking scalability. Additionally, it increases expensive computation, communication costs and delay. To overcome this problem, Robust Security for Protected Health Information by ECC with signature Hash Function in WBAN (RSP) is proposed. The system employs hash-chain based key signature technique to achieve efficient, secure transmission from sensor to user in WBAN. Moreover, Elliptical Curve Cryptography algorithm is used to verifies the authenticate sensor. In addition, it describes the experimental results of the proposed system demonstrate the efficient data communication in a network.

Modeling of a novel biosensor with integrated mass and electrochemical sensing capabilities

Rapid development in technology and society has generated diverse developments in many fields including biosensors in healthcare application. Here, the design of integrated biosensor comprises mass sensing (Quartz Crystal Microbalance) and electrochemistry sensing (Electrochemical Impedance Spectroscopy, EIS and Cyclic Voltammetry, CV) will be presented. The integrated sensor system is developed based on the innovative use of the top electrode of a quartz crystal microbalance (QCM) resonator as a working electrode for the electrochemistry technique. Integration of QCM with the electrochemistry technique is realized by fabricating a semicircular counter electrode near the upper electrode on the same side of the quartz crystal. CV and EIS measurement was conducted using finite element modeling, COMSOL™ 5.2 with the probe marker of 1 mmol L−1 of [Fe(CN)6]3-/4- CV test was done to study the effect between increasing scan rate and peak current (anodic and cathodic) in observing the reversible electrochemical process. This observation is crucial in ensuring the electrochemical processes follow the Randles-Sevcik equation in characterizing the platform changes behavior. Later, EIS test was performed in order to measure the radius of the semicircle which reflects the charge transfer resistance (RCT) of the redox marker. To show the effectiveness of this sensor, gold immobilization surface was electrochemically simulated and reported. Thus, an ultra-sensitive biosensor that capable to produce multi-analysis in the detection of biological targets in terms of electrochemical change of electrode interfaces, which is the crucial step towards the engineering of advanced bioelectronics.

Design of Two-Stage CMOS amplifier for quartz crystal resonator

Quartz crystal oscillators is widely used in many types of electronics equipment for our daily life applications such as mobile communication, military, industrial measurement, an others due to its high stability clock sources. In this paper, a Two-Stage CMOS op-amp for a quartz crystal-based oscillator is presented. The design of two-stage CMOS op amp is critically discussed. Two-stage CMOS op amp is consist of two stages. Each stage can be designed with various amplifier topologies. The first stage is differential amplifier. The second stage of two-stage op amp is a common-source amplifier. The op amp achieves a gain of 6.134 dB at VDD of 3.3 V and VSS of -3.3 V. The two-stage CMOS op amp is combined with 10 MHz quartz crystal resonator to create an oscillator at the frequency of ~10MHz. The gain of 13.32dB is achieved. This oscillator is simulated using Cadence in MIMOS 0.35 um CMOS process.