Tomy Abuzairi

Maskless localized patterning of biomolecules on carbon nanotube microarray functionalized by ultrafine atmospheric pressure plasma jet using biotin-avidin system

Ultrafine plasma jet is a promising technology with great potential for nano- or micro-scale surface modification. In this letter, we demonstrated the use of ultrafine atmospheric pressure plasma jet (APPJ) for patterning bio-immobilization on vertically aligned carbon nanotube (CNT) microarray platform without a physical mask. The biotin-avidin system was utilized to demonstrate localized biomolecule patterning on the biosensor devices. Using ±7.5 kV square-wave pulses, the optimum condition of plasma jet with He/NH3 gas mixture and 2.5 s treatment period has been obtained to functionalize CNTs. The functionalized CNTs were covalently linked to biotin, bovine serum albumin (BSA), and avidin-(fluorescein isothiocyanate) FITC, sequentially. BSA was necessary as a blocking agent to protect the untreated CNTs from avidin adsorption. The localized patterning results have been evaluated from avidin-FITC fluorescence signals analyzed using a fluorescence microscope. The patterning of biomolecules on the CNT mic...

Design of wearable health monitoring device

Wearable smart health monitoring devices have attracted considerable attention in both research community and industry. Some of the causes are the increasing healthcare costs, along with the growing technology. To address this demand, in this paper, design and evaluation of wearable health monitoring device integrated with smartphone were presented. This device was designed for patients in need of constant health monitoring. The performance of the proposed design has been tested by conducting measurement once in 2 minutes for 10 minutes to obtain heart rate and body temperature data. The comparation between data measured by the proposed device and that measured by the reference device yields only an average error of 1.45% for heart rate and 1.04% for body temperature.Wearable smart health monitoring devices have attracted considerable attention in both research community and industry. Some of the causes are the increasing healthcare costs, along with the growing technology. To address this demand, in this paper, design and evaluation of wearable health monitoring device integrated with smartphone were presented. This device was designed for patients in need of constant health monitoring. The performance of the proposed design has been tested by conducting measurement once in 2 minutes for 10 minutes to obtain heart rate and body temperature data. The comparation between data measured by the proposed device and that measured by the reference device yields only an average error of 1.45% for heart rate and 1.04% for body temperature.

Design of fiber optic based respiratory sensor for newborn incubator application

This paper reports the design of respiratory sensor using fiber optic for newborn incubator application. The sensor works based on light intensity losses difference obtained due to thorax movement during respiration. The output of the sensor launched to support electronic circuits to be processed in Arduino Uno microcontroler such that the real-time respiratory rate (breath per minute) can be presented on LCD. Experiment results using thorax expansion of newborn simulator show that the system is able to measure respiratory rate from 10 up to 130 breaths per minute with 0.595% error and 0.2% hysteresis error.

Investigation on physicochemical properties of plasma-activated water for the application of medical device sterilization

Plasma activated water (PAW) is a new approach to bacterial inactivation while ensuring safety and maintaining the properties of the material sterilized. Reported research imply that PAW has been effective for inactivation of bacteria. In this paper, plasma treatment using atmospheric pressure plasma was demonstrated. Physicochemical properties such as pH, temperature, ORP, and nitrite concentration were assessed. The results suggest that plasma treatment causes acidification on water and generate reactive species, creating an environment suitable for killing bacteria. Therefore, plasma activated water is an assuring method for medical devices sterilization.Plasma activated water (PAW) is a new approach to bacterial inactivation while ensuring safety and maintaining the properties of the material sterilized. Reported research imply that PAW has been effective for inactivation of bacteria. In this paper, plasma treatment using atmospheric pressure plasma was demonstrated. Physicochemical properties such as pH, temperature, ORP, and nitrite concentration were assessed. The results suggest that plasma treatment causes acidification on water and generate reactive species, creating an environment suitable for killing bacteria. Therefore, plasma activated water is an assuring method for medical devices sterilization.

Design of portable electrocardiogram device using DSO138

Cardiovascular disease has been one of the leading causes of sudden cardiac deaths in many countries, covering Indonesia. Electrocardiogram (ECG) is a medical test to detect cardiac abnormalities by measuring the electrical activity generated by the heart, as the heart contracts. By using ECG, we can observe anomaly at the time of heart abnormalities. In this paper, design of portable ECG device is presented. The portable ECG device was designed to easily use in the village clinic or houses, due to the small size device and other benefits. The device was designed by using four units: (1) ECG electrode; (2) ECG analog front-end; (3) DSO138; and (4) battery. To create a simple electrode system in the portable ECG, 1-lead ECG with two electrodes were applied. The analog front-end circuitry consists of three integrated circuits, an instrumentation amplifier AD820AN, a low noise operational amplifier OPA134, and a low offset operational amplifier TL082. Digital ECG data were transformed to graphical data on DSO138. The results show that the portable ECG is successfully read the signal from 1-lead ECG system.

Band-gap optimization for improvement Cu(in, Ga)Se 2 (CIGS) solar cell

Tropical countries, such as Indonesia, need to consider the thread-off between high average solar irradiance throughout the year and the sporadic clouds due to the high rainfall in utilization of solar energy conversion Cu(In, Ga)Se2 (CIGS) with Polyimide substrate is known as one of the materials that produces significant power under low-light and cloudy condition. This 3rd generation solar cell is also promising for thin-film application. Due to Polyimide low thermal stability, a notch problem which significantly affected the current density (Jsc) arose. Single-graded flat-band structure was proven to be an option to solve this situation. In this research, further simulation was run to find the optimum design of this structure.

Fluorescence Analysis of Micro-scale Surface Modification Using Ultrafine Capillary Atmospheric Pressure Plasma Jet for Biochip Fabrication

In this study, we propose the micro-scale surface functionalization techniques using a maskless, versatile, simple tool, represented by a nano- or micro-capillary atmospheric pressure plasma jet (APPJs). We show the possibility of size-controlled surface functionalization on polymer substrate with amino groups or carboxyl groups by using fluorescent technique. Moreover, we prove the successful connection of biomolecules on the functionalized micro-scale patterns, indicating the possibility to use ultrafine capillary APPJs as versatile tools for biosensing, tissue engineering, and related biomedical applications. With use of this technology, we study the biomolecules patterning onto CNT dot array via ultrafine APPJ for biochip fabrication. An ultrafine APPJ with a micro-capillary was utilized to functionalize amino groups on designated CNT spots. Two-stage plasma treatments, pre-treatment and post-treatment, were conducted to functionalize CNT array by ultrafine APPJ. Biomolecules system, such as biotin-avidin system was employed to assess the feasibility of biomolecule immobilization on CNT. The possibility of this technique for micro-biochip applications was successfully demonstrated by patterning biomolecules onto CNT microarrays.

The effect of waveguide parameters on gan based S-bend Y-junction optical power divider

GaN-based structures have attracted many researchers in developing photonic devices. These semiconductor structures can operate at high temperatures and high-power levels due to their mechanical hardness. So far, optical splitters design based on Y-junction splitters are widely used on the various material structure. The problem of these structures is radiation loss at the junction area. In this paper, we study the effect of various waveguide parameters on GaN-based S-bend Y-junction optical power divider. The design consists of three sections: linear rectangular rib waveguide, parabolic taper and two S-bend sine branches with the total length of 1000μm. We use optical beam propagation methods (BPM) to obtain the characteristic of the guided wave to calculate the field propagation through the structure as a function of waveguide parameters, such as branching angle and input wavelength. All simulations are carried out using the OptiBPM software. From the simulation results, it shows that to maintain 90% transmitted power, the branching angle for the design should be at the range of 0.5–1.5°. It is also demonstrated that the transmitted power almost stable through the wavelength range from 1.5 up to 1.6 μm with an average of power loss at about 0.35 dB. The simulation results presented can be applied for future GaN Y-junction based waveguide photonic devices design.

A Simple Optimization of Triple-Junction Solar Cell nc-Si:H/a-Si:H/a-SiGe:H Using Computer Modeling and Robust Design

We report for the first time a simple optimization of triple-junction solar cell nc-Si:H/a-Si:H/a-SiGe:H using computer modeling and Robust Design. Firstly we performed a computer modeling of solar cell by wxAMPS software. Subsequently, we investigated the parameters of the solar cell layers and the effect of the solar cell efficiency using Robust Design via Taguchi method, ANOVA and additive model. The results show that the a-Si:H middle absorber cell has the highest contribution of solar cell efficiency at 40.87% and the nc-Si:H n-back layer cell has the second highest contribution of solar cell efficiency at 31.15%. Moreover, the optimum condition for triple-junction solar cell is A2 B1 C2 D2 with solar cell efficiency at 15.73%. These results indicate that Robust Design succeeded predicting the best condition for optimizing triple-junction solar cell nc-Si:H/a-Si:H/a-SiGe:H.