Zuraini Dahari

Electromagnetic micro power generator — A comprehensive survey

This paper presents a comprehensive survey on vibration powered electromagnetic micro generator, which harvest mechanical energy from environment and convert this energy into useful electrical power for micro system and sensor node. The on-going research works on electromagnetic micro generator are reviewed as a background of this paper. Basic theories of micro generator to produce power from ambient motion by damping the suspended proof mass system over the coils are presented. Several important parameters such as the shape, types of magnet, spring and coil property used in designing electromagnetic micro generator as well as power processing circuit are also included. Different designs of micro generator for different environment and application are discussed. Significant challenges in converting the power by each design are also highlighted in this paper.

Harvesting Raindrop Energy with Piezoelectrics: a Review

Harvesting vibration energy from piezoelectric material impacted by raindrops has proved to be a promising approach for future applications. A piezoelectric harvester has interesting advantages such as simple structure, easy fabrication, reduced number of components, and direct conversion of vibrations to electrical charge. Extensive research has been carried out and is still underway to explore this technique for practical applications. This review provides a comprehensive picture of global research and development of raindrop energy harvesting using piezoelectric material to enable researchers to determine the direction of further investigation. The work published so far in this area is reviewed and summarized with relevant suggestions for future work. In addition, a brief experiment was carried out to investigate the suitable piezoelectric structure for raindrop energy harvesting. Results showed that the bridge structure generated a higher voltage compared with the cantilever structure.

Piezoelectric Beam Length Optimization for Raindrop Energy Harvesting Application

The vibration energy harvesting from raindrop is an interesting and potential approach for future applications. This article presents the piezoelectric based beam length optimization for raindrop energy harvesting application. In this work, polyvinylidene fluoride (PVDF) is selected as piezoelectric material. The characteristics and performances of the beam are experimentally investigated. It includes investigation on the impact of water droplets with 4.3 mm diameter, released from 0.25 m heights at various lengths of PVDF beam. The width and thickness of the beam are fixed to 4 mm and 25 μm respectively. Results showed that the optimized length which is 30 mm is possible to generate peak voltage up to 8.5 V.

Human body parts heat energy harvesting using thermoelectric module

Energy harvesting has become of a growing interest recently due to its potential to be utilized in wide area of self powered systems. The concept of energy harvesting is to capture unused ambient energy and convert into usable electrical energy which is stored and used for performing sensing or actuation. The latest advancement is focusing on energy scavenging system to power small and autonomous electronic devices. The main advantages of energy harvesting concept lie on the portability, clean, reduce dependency on battery power and it also offers long-term solutions. This research focuses on the human heat energy harvesting which converts human waste heat to electricity. This paper focuses on extracting heat energy from five parts of human body heat such as human palm, top palm, wrist, top wrist and leg. Thermoelectric module is utilized to convert the human body heat to electricity. A booster circuit is developed to boost the weak voltage to higher voltage in order to power up an LED as output indicator. Based on experimental results, the maximum output voltage from thermoelectric module obtained is from the human palm part, which is 0.1 V. It is able to be boosted up to 2.9 V at the voltage booster output. The output voltage generated at load is 2.47 V and the power output is 24.7 mW.

An Investigation of Raindrop Size in Raindrop Energy Harvesting Application via Photography and Image Processing Approach

Renewable energy is gaining more attention as a new source of energy. Among all the renewable energies, kinetic energy is the most readily available energy source. One of potential kinetic energy to be utilized in energy harvesting is from the raindrop energy. The generated energy depends greatly on the size of raindrops. Therefore, it is important to study the raindrops characteristics prior for further investigation in the raindrop energy. This paper discusses the prediction of the size of raindrop based on simulated droplet using syringe pump. Edge detection segmentation method is applied to the image to detect the diameter of water droplet.

A comparative study of electromagnetic generator via finite element element analysis

Energy scavenging from ambient sources is an attractive alternative to batteries because of an almost unlimited lifetime and is environmentally safe. Environmental vibration is a particularly attractive energy source because of its abundance, and several scavenging techniques such as piezoelectric, electrostatic and electromagnetic (EM) transduction. Since it is quite easy to keep a strong magnetic field with a permanent magnet, electromagnetic vibration-power generators are preferred in many applications. This paper presents a comparative study of electromagnetic generator via Finite Element Analysis (FEA). It involves the investigation of the magnetic behaviours for several configurations of electromagnetic generator. The configuration varies in terms of types of magnet and the arrangement of the magnet. Finite element models are developed and further analyzed via ANSYS software. Analyses are conducted prior to investigate the magnetic behaviours of the electromagnetic generator such as the flux lines, the magnetic flux density and also the electromotive force (emf) produced.

Continuous quality improvement (CQI) implementation in electrical & electronic engineering final year projects

Outcome Based Education (OBE) approach has become a compulsory process in ensuring the quality of undergraduate programs offered in recognized tertiary institutions. It focuses on the measurable outcome of the achievement of the students in terms of the skills and abilities to prepare themselves before embarking upon their career path. The final year project (FYP) is one of the major subjects in an engineering program. It can be considered as a problem based learning (PBL) subject where students need to apply and integrate their theoretical knowledge and skills to solve a given task in two academic semesters. Due to the significant number of credit units allocated for this subject, it has become an essential subject to focus on during the accreditation process. As the accreditation process proceeds and progresses, it should consider the improvised actions that would be necessary to improve the quality of the program, which is the continuous quality improvement (CQI) cycle. This paper focuses on the implementation of the CQI process in an electrical & electronic engineering final year project implementation. It describes the comments and feedbacks from the stakeholders and the implemented CQI actions to address the uprising issues during the accreditation process.

Analysis of cantilever characteristics in designing electromagnetic generator

Vibration energy harvesting is one of potential renewable energy that may replace conventional chemical battery as energy source for powering wireless micro-system. One of the vibration energy harvester designs makes use of Faradays law of induction which is electromagnetic method. This type micro-generator generally consists of cantilever, magnets and coils. The generator uses two magnets arranged on the top and bottom at the end of cantilever while another end is fixed. The coils are placed beside two sides of the magnets. This paper presents an analysis of the cantilever by varying the physical dimension of the cantilever such as length, thickness and width. The analysis includes the resonant frequency of the cantilever and also the deflection under damping ratio. There is small difference between ANSYS simulation and theoretical calculation, which is about 1.4%. The adjustment of the length of cantilever provides the largest range of tuning frequency among the above mention parameters.

Development of At-speed Interconnect Test to Capture Marginal Open Defect on FPGA

This paper highlights the development of FPGA interconnect at-speed test to capture marginal open defect on Altera® Stratix V devices. The need for at-speed test was due to the increasing number of marginal open defects, resulting from manufacturing process complexity anticipated on nanometer (nm) scale IC fabrication process. Towards the final implementation, there are few unique design implemented in order to generate the at-speed clocks and the pipelined scan enable signals to support Launch on Shift (LOS) method. Meanwhile, the ability to test the interconnect on at-speed frequency required new routing tool control variables to limit the interconnect path lengths and device power consumption. The LOS test patterns used in this research managed to cover up to 81 % of the overall routing resources for marginal open defect effectively. Furthermore, the test was successfully implemented at frequencies up to 400 MHz and proven to be sensitive to routing delay to capture marginal open defects.

A study on performance enhancement of electromagnetic generator via Finite Element Analysis

Kinetic energy in vibration form is considered as one of potential renewable energy that may power up wireless micro-system. This energy can be converted into electrical energy via vibration energy harvester which makes use of Faradays law of induction. The harvester generally consists of cantilever as spring, magnets and coils. Two magnets are arranged on the bottom and top at one end of cantilever while another end is fixed. The coils are placed beside two sides of the magnets. This paper presents a design and modelling of harvester with high permeability material. The main objective of this paper is to investigate the impact of placing high permeability material besides the coil in order to enhance the performance of the harvester. Analyses are conducted by comparing the magnetic flux density for different configurations. The magnetic flux density along the coils is reported 0.149 T, 0.228 T and 0.21 T for Configuration I, II, and III, respectively. The performance of Configuration III is optimized by vary the height and thickness of high permeability material to obtain 0.24 T along the coil. Electromotive force generation among configurations also presented.