Dilla Duryha Berhanuddin

Designing a boost converter of micro energy harvester using thermal and vibration input for biomedical devices

This work presents a designed of boost converter Hybrid Micro Energy Harvester (HMEH) using thermal and vibration of human body for biomedical application. Thermal converts temperature differences directly into electrical energy. While vibration is based on human movement like walking and shaking body that is able to generate an AC voltage. Having two sources overcome the limitation caused by a single source harvester and improves system functionality. The inputs are set to 0.2V, 0.3V and 0.5V to represent thermal, vibration and combination of thermal and vibration (hybrid) respectively. A rectifier is designed to convert vibration input from AC to DC voltages. The proposed boost converter is used to step-up the small input voltage from thermal and vibration at 2 kHz. The inductance is varied from 0.4μH to 1.2μH, 0.9μH to 2.9μH and 0.3μH to 0.9μH for vibration, thermal and hybrid input respectively. However, the optimize value for the designed is 0.9μH for all sources to achieve the regulated output of 2.0 to 4.0V. Both rectifier and boost converter circuit consist of MOSFET as the heart of the operation. In this paper, the circuits are designed, modeled and simulated using PSPICE software.

Higher Sensitivity RF-DC Rectifier for Ultra-Low Power Semi-Active RFID Tags

Radio frequency (RF) energy harvesting is the process where energy is captured from the radiated RF signals and converted it to electrical power to supply a very small amount of power to modern electronic devices. This paper presents a RF energy harvester for ultra-low power semi-active UHF radio frequency identification tag applications. The main objective is to solve the semi-active UHF RFID tag limited lifespan issues due to the need for batteries to power its circuitries.In this design, the energy from the radiated RF signals is converted to electrical power by a module known as RF-DC rectifier. The circuit is based on a cross-connected differential-drive CMOS rectifier topology which is implemented in 0.13 μm CMOS standard technology with the input RF power range from -20 dBm to -10 dBm operating in 915 MHz frequency band. To ensure a maximum output voltage is achieved, several simulations based on the optimized matching network components, the variation of transistor sizes and load resistance, and increases the number of rectifier stages are investigated. All the circuit designs and simulations are performed using Orcad Cadance software. The simulated results shown that the optimized impedance matching network and a six-stage cross-connected differential-drive CMOS rectifier circuit able to produces a 1.13 V DC output voltage with an input power of -10 dBm (100 μW) and 1 MΩ load resistance.The results obtained shows that the proposed design can extend the lifetime of semi-active UHF RFID tag, able to eliminate its dependency on battery and make it possible to achieve a batteryless tag. Therefore, can be used to supply electrical power continuously for RFID tag applications.

Urea and creatinine detection on nano-laminated gold thin film using Kretschmann-based surface plasmon resonance biosensor

This work investigates the surface plasmon resonance (SPR) response of 50-nm thick nano-laminated gold film using Kretschmann-based biosensing for detection of urea and creatinine in solution of various concentrations (non-enzymatic samples). Comparison was made with the presence of urease and creatininase enzymes in the urea and creatinine solutions (enzymatic samples), respectively. Angular interrogation technique was applied using optical wavelengths of 670 nm and 785 nm. The biosensor detects the presence of urea and creatinine at concentrations ranging from 50–800 mM for urea samples and 10–200 mM for creatinine samples. The purpose of studying the enzymatic sample was mainly to enhance the sensitivity of the sensor towards urea and creatinine in the samples. Upon exposure to 670 nm optical wavelength, the sensitivity of 1.4°/M was detected in non-enzymatic urea samples and 4°/M in non-enzymatic creatinine samples. On the other hand, sensor sensitivity as high as 16.2°/M in urea-urease samples and 10°/M in creatinine-creatininase samples was detected. The enhanced sensitivity possibly attributed to the increase in refractive index of analyte sensing layer due to urea-urease and creatinine-creatininase coupling activity. This work has successfully proved the design and demonstrated a proof-of-concept experiment using a low-cost and easy fabrication of Kretschmann based nano-laminated gold film SPR biosensor for detection of urea and creatinine using urease and creatininase enzymes.

Photonic crystal (PhC) nanowires for infrared photodetectors

We report the Photonic Crystal (PhC) nanowires performance for potential phototodetectors integration application. The refractive index of PhC can be tailored to guide specific resonance wavelength precisely. This paper presents the numerical approach of 1D PhC with 12 periodic holes to observe the range of stop band acquired, transmission and the quality factor of the resonance wavelengths. By splitting the holes equally with a range of cavities from 440 to 450 nm, the stop band observed are between 1.5 to 2.1 μm. By varying the cavity length, the value of resonance wavelengths and quality factors observed have also changed. The introduction of 442 nm cavity shows the highest transmission but the lowest Quality factor (Q-factor) where both are observed at 0.87 and 284 respectively. The values indicate a good confinement of light in the waveguide designed thus enabling wavelength selectivity for photodetectors application in highly sensitive wavelength selection application.

Photoluminescence study of the optically active, G-centre on pre-amorphised silicon by utilizing ion implantation technique

We report a new approach of generating the dicarbon G-centre on silicon substrates by utilizing technique that is fully compatible with the standard silicon ultra-large-scale integration (ULSI) technology. Silicon wafers were implanted with carbon and irradiated with high energy protons to produce self-interstitials that are crucial in the formation of the G-centre. Prior to that, all the samples were pre-amorphised with germanium. Photoluminescence (PL) measurements at 80 K were carried out to investigate the point defect mediated luminescence of the G-centre with a wavelength of 1280 nm. The results show a prominent, sharp luminescence at the carbon related, G centre in majority of the samples.

Performance evaluation of the UHF class 0 RFID tag for the proposed anti-collision algorithm

The Radio Frequency Identification (RFID) system is an automatic identification technology of choice over other existing technologies. Nowadays, the ability to identify many objects simultaneously is crucial for more advanced applications such as to identify objects in the warehouse and at the supermarket. These applications require an efficient identification technique which can identify many objects at one time without long delay. Meanwhile, one of the main issues during the identification process is the tags collision which occurs when all these tags are simultaneously responding to the reader commands. The RFID applications also require the tag to be simple, small, cheap and memoryless. Therefore the research is to evaluate the the performance of the proposed tag architecture for the Fast Detection Anti-collision Algorithm (FDACA) using the Total Tag Replies parameter. The Total Tag Replies parameter for the Binary Tree and the proposed FDACA tags are explained. The tag architecture for both techniques are described in Verilog Hardware Description Language (HDL) and simulated using Xilinix software. Then both tag architectures are synthesized using Application Specific Integrated Circuit (ASIC) technology (0.18 μm Library, Synopsys Compiler and tools). The tags performances are evaluated based on the obtained synthesis parameters.

Structural damage of Si-implanted in the In 0.53 Ga 0.47 As thin film

Damage profiling of implanted ions in semiconductors layer is crucial in order to accurately estimate the ion distribution and concentration in the target substrates. It also gives the predicted number of vacancies and interstitials after the collision events. This is particularly important prior to the ion implantation so as to reduce the defect formation and damage to the targets lattice which subsequently degrade the performance of the device. In this paper, we studied the optimized energy and range of ions implanted silicon in In0.53Ga0.47As film by utilizing the Stopping Range of Ions in Matter (SRIM) simulation. The effects of implantation energy in different thickness are also discussed based on creation of phonons, vacancies and ionization.