Design and Optimization of Inductively Coupled Spiral Square Coils for Bio-Implantable Micro-System Device

Due to the development of biomedical microsystems technologies, the use of wireless power transfer systems in biomedical application has become very largely used for powering the implanted devices. The wireless power transfer by inductive resonance coupling link, is a technic for powering implantable medical devices (IMDs) between the external and implanted circuits. In this paper we describe the design of an inductive resonance coupling link using for powering small bio-implanted devices such as implantable bio-microsystem, peacemaker and cochlear implants. We present the reduced design and an optimization of small size obtained spiral coils of a 9.5 mm2 implantable device with an operating frequency of 13.56 MHz according to the industrial scientific-medical (ISM). The model of the inductive coupling link based on spiral square coils design is developed using the theoretical analysis and optimization geometry of an inductive link. For a mutual distance between the two coils at 10mm, the power transfer efficiency is about 79% with , coupling coefficient of 0.075 and a mutual inductance value of 2µH. In comparison with previous works, the results obtained in this work showed better performance such as the weak inter coils distance, the hight efficiency power transfer and geometry

A review on wireless power transfer: Concepts, implementations, challenges, and mitigation scheme

This paper reviews the current strides in the wireless power transfer (WPT) system. The paper discusses the classification of wireless power transfer, its application, trend and impact on society, advantages as well as disadvantages. It also presents a comparative analysis of existing work done by researchers in the field of wireless power transfer showing the shortcomings in various topologies, communication, and optimization methods used to increase the overall performance efficiency and proffer direction for further studies. Keywords: wireless power transfer, application, advantages, disadvantages topologies, communication, optimization, efficienc

Electromagnetic Pigging System Based on Sandwich Differential Planar Coil

In-pipeline inspection is an important precontrol method to ensure the safety of oil and gas pipeline transportation. This article proposes an electromagnetic in-pipe detector based on passive resonance-enhanced differential planar coils to detect defects on the inner surface of pipes. Both qualitative and quantitative analyses of pipeline defects and damage are developed. The introduction of passive resonant coils is shown to significantly improve the detection capability of the sensor. This is coupled with the establishment of a theoretical derivation model of the proposed structure. The hardware platform of the laboratory system has been built, and an eddy current internal detector suitable for 8-in-diameter pipes is developed and integrated into the system. Numerical simulations and experimental verifications on flat defects and pipe defects have been undertaken. The obtained results have shown that the real defects have been correctly detected, and the system is effective, reliable, and efficient

Master of Science

thesisThis thesis discusses the design, modeling, and experimental validation of an inductively coupled wireless power transfer (WPT) system to power a micro aerial vehicle (MAV) without an onboard power source. MAVs are limited in utility by flight times ranging from 5 to 30 minutes. Using WPT for MAVs, in general, extends flight time and can eliminate the need for batteries. In this paper, a resonant inductive power transfer system (RIPT), consisting of a transmit (Tx) coil on a fixed surface and a receive (Rx) coil attached to the MAV, is presented, and a circuit is described. The RIPT system design is modeled to determine a suitable geometry for the coils, and the model validated experimentally. It is found that for the MAV used in this work, a suitable geometry of coils is a 19cm diameter planar spiral Tx coil made with 14 AWG copper wire, seven turns, and 5cm pitch paired with an Rx coil made of 16-20AWG wire, 13cm-20cm diameter, 1mm pitch, and one to two turns. A demonstration of an MAV being powered 11cm above the Tx coil with the WPT system in a laboratory setting is presented. The MAV consumes approximately 12 Watts. The overall power efficiency of the RIPT system from RF power source output to MAV motors is approximately 32%

Investigation of Tx-Rx mutual inductance eddy current system for high lift-off inspection

PhD ThesisEddy current (EC) testing is a popular inspection technique due to its harsh environment tolerance and cost-effectiveness. Despite the immense research in EC inspection, defect detection at high lift-off still poses a challenge. The weakening mutual coupling of EC probe and sample due to the increase in lift-off degrades signal strength and thus reduces the detection sensitivity. Although signal processing can be used to mitigate lift-off influence, it is laborious and time consuming. Therefore, in this study, a Tx-Rx probe system is proposed to deal with high lift-off inspection. The parts of the study of the Tx-Rx EC system includes optimisation of probe configuration, improvement of signal conditioning circuit and comparative study of excitation modes. In optimisation of probe configuration, lift-off and coil gap are optimized to mitigate the offset caused by the direct coupling of Tx-Rx coils. The optimum coil gaps of Tx-Rx probe for different lift-offs are found by observing the highest signal strength. The optimisation of coil gap against lift-off extends the detection sensitivity of the EC system to a lift-off of about 30 mm which is by far higher than 5 mm lift-off limit of a single-coil EC probe. In signal conditioning aspect, a modified Maxwell bridge circuit is designed to remove the offset due to self- impedance of the Rx coil. The proposed circuit mitigates the influence of the self-impedance of Rx coil and improves signal-to- noise ratio SNR. In the excitation mode, pulse and sweep frequency signals are compared to study detection sensitivity, SNR and crack quantification capability. The result of the comparative study reveals that pulse excitation is good for crack sizing while sweep frequency excitation is better for crack detection. Simulations and experimental studies are carried out to show the efficacy of the Tx-Rx EC system in high lift-off crack detection

Transferência de Energia sem Contacto: Estudo das Emissões dо Campo Elétrico

O aumento do valor da energia transferida e da distância da transferência tornou importante a questão de limitação das emissões eletromagnéticas irradiadas pelo sistema de transferência de energia sem contacto que podem afetar de forma adversa os seres vivos, os equipamentos eletrónicos e o canal de comunicação. Este trabalho é uma contribuição para o estudo da componente elétrica do campo eletromagnético irradiado pelo sistema de transferência de energia sem contacto para o ambiente envolvente. A transferência de energia sem contacto e a transmissão de dados sem fio são estudadas simultaneamente, com enfoque sobre o canal de comunicação sem fios adequado, que permite melhorar a comunicação entre o transmissor e o recetor. É estudado o impacto das emissões eletromagnéticas irradiadas sobre os seres vivos e sobre o canal de comunicação. O estudo está focado na intensidade e na distribuição da componente elétrica do campo eletromagnético produzido pelo sistema de transferência de energia com enfoque nos níveis de segurança na exposição ao campo elétrico, recorrendo aos modelos computacionais desenvolvidos utilizando o método dos elementos finitos. Para a validação experimental dos modelos computacionais são realizadas medições dos níveis do campo elétrico produzido pelo sistema. Os resultados experimentais são comparados com as normas de segurança estabelecidas pelos organismos internacionais para a verificação da compatibilidade eletromagnética. É implementado um protótipo experimental de transferência de energia sem contacto que opera simultaneamente com uma transmissão de dados sem fio. É desenvolvida uma aplicação computacional que permite sintonizar o modo de funcionamento do protótipo para o regime de ressonância