scholarly journals Hybrid Coils-Based Wireless Power Transfer for Intelligent Sensors

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2549
Author(s):  
Mustafa F. Mahmood ◽  
Saleem Lateef Mohammed ◽  
Sadik Kamel Gharghan ◽  
Ali Al-Naji ◽  
Javaan Chahl
Keyword(s):  
Heart Rate ◽  
Power Efficiency ◽  
Wireless Power Transfer ◽  
Power Measurement ◽  
Measurement Unit ◽  
Resistive Load ◽  
Power Transfer ◽  
Wireless Power ◽  
Harvesting Technique ◽  
Rate Sensor

Most wearable intelligent biomedical sensors are battery-powered. The batteries are large and relatively heavy, adding to the volume of wearable sensors, especially when implanted. In addition, the batteries have limited capacity, requiring periodic charging, as well as a limited life, requiring potentially invasive replacement. This paper aims to design and implement a prototype energy harvesting technique based on wireless power transfer/magnetic resonator coupling (WPT/MRC) to overcome the battery power problem by supplying adequate power for a heart rate sensor. We optimized transfer power and efficiency at different distances between transmitter and receiver coils. The proposed MRC consists of three units: power, measurement, and monitoring. The power unit included transmitter and receiver coils. The measurement unit consisted of an Arduino Nano microcontroller, a heart rate sensor, and used the nRF24L01 wireless protocol. The experimental monitoring unit was supported by a laptop to monitor the heart rate measurement in real-time. Three coil topologies: spiral–spiral, spider–spider, and spiral–spider were implemented for testing. These topologies were examined to explore which would be the best for the application by providing the highest transfer power and efficiency. The spiral–spider topology achieved the highest transfer power and efficiency with 10 W at 87%, respectively over a 5 cm air gap between transmitter and receiver coils when a 200 Ω resistive load was considered. Whereas, the spider–spider topology accomplished 7 W and 93% transfer power and efficiency at the same airgap and resistive load. The proposed topologies were superior to previous studies in terms of transfer power, efficiency and distance.

scholarly journals Ultrasound Sensor-Based Wireless Power Transfer for Low-Power Medical Devices

2019 ◽  
Vol 9 (3) ◽  
pp. 20 ◽  
Author(s):  
Mustafa F. Mahmood ◽  
Saleem Latteef Mohammed ◽  
Sadik Kamel Gharghan
Keyword(s):  
Heart Rate ◽  
Low Power ◽  
Power Unit ◽  
Medical Devices ◽  
Wireless Power Transfer ◽  
Measurement Unit ◽  
Power Transfer ◽  
Rate Measurement ◽  
Wireless Power ◽  
Heart Rate Measurement

Ultrasonic power transfer (UPT) is a promising method for wireless power transfer technology for low-power medical applications. Most portable or wearable medical devices are battery-powered. Batteries cannot be used for a long time and require periodic charging or replacement. UPT is a candidate technology for solving this problem. In this work, a 40-KHz ultrasound transducer was used to design a new prototype for supplying power to a wearable heart rate sensor for medical application. The implemented system consists of a power unit and heart rate measurement unit. The power unit includes an ultrasonic transmitter and receiver, rectifier, boost converter and super-capacitors. The heart rate measurement unit comprises measurement and monitoring circuits. UPT-based transfer power and efficiency were achieved using 1-, 4- and 8-Farad (F) super-capacitors. At 4 F, the system achieved 69.4% transfer efficiency and 0.318 mW power at 4 cm. In addition, 97% heart rate measurement accuracy was achieved relative to the benchmark device. The heart rate measurements were validated with statistical analysis. Our results show that this work outperforms previous works in terms of transfer power and efficiency with a 4-cm gap between the ultrasound transmitter and receiver.

scholarly journals Preliminary study of 50 W Class-E GaN FET amplifier for 6.78 MHz capacitive wireless power transfer

2020 ◽  
Vol 11 (1) ◽  
pp. 22
Author(s):  
Aam Muharam ◽  
Tarek Mahmoud Mostafa ◽  
Suziana Ahmad ◽  
Mitsuru Masuda ◽  
Daiki Obara ◽  
...  
Keyword(s):  
High Frequency ◽  
Power Efficiency ◽  
Wireless Power Transfer ◽  
Load Parameter ◽  
Resistive Load ◽  
Power Transfer ◽  
Wireless Power ◽  
Preliminary Study ◽  
High Frequency Operation ◽  
Class E

A preliminary study of Class-E radio frequency power amplifier for wireless capacitive power transfer (CPT) system is presented in this paper. Due to a limitation in coupling capacitance value, a high frequency operation of switching power inverter is necessary for the CPT system. A GaN MOSFET offers reliability and performance in a high frequency operation with an improved efficiency over a silicon device. Design specification related to the parallel load parameter, LC impedance matching and experimental analysis of the amplifier is explored. An experimental setup for the proposed inverter and its integration with the CPT system is provided, and the power efficiency is investigated. As a result, by utilizing a 6.78 MHz resonant frequency and a 50 Ω resistive load, 50 W of power has been transmitted successfully with an end to end system efficiency over 81 %. Additionally, above 17 W wireless power transfer was demonstrated successfully in the CPT system under 6 pF coupling with the efficiency over 70 %.

scholarly journals Design of Powering Wireless Medical Sensor Based on Spiral-Spider Coils

Designs ◽  
2021 ◽  
Vol 5 (4) ◽  
pp. 59
Author(s):  
Mustafa F. Mahmood ◽  
Sadik Kamel Gharghan ◽  
Saleem Latteef Mohammed ◽  
Ali Al-Naji ◽  
Javaan Chahl
Keyword(s):  
Heart Rate ◽  
Measurement Accuracy ◽  
Measurement Unit ◽  
Operating Voltage ◽  
Power Transfer ◽  
Wireless Power ◽  
Biomedical Sensors ◽  
Battery Capacity ◽  
Resonance Coupling ◽  
Rate Sensor

Biomedical sensors help patients monitor their health conditions and receive assistance anywhere and at any time. However, the limited battery capacity of medical devices limits their functionality. One advantageous method to tackle this limited-capacity issue is to employ the wireless power transfer (WPT) technique. In this paper, a WPT technique using a magnetic resonance coupling (MRC-WPT)-based wireless heart rate (WHR) monitoring system—which continuously records the heart rate of patients—has been designed, and its efficiency is confirmed through real-time implementation. The MRC-WPT involves three main units: the transmitter, receiver, and observing units. In this research, a new design of spiral-spider coil was designed and implemented for transmitter and receiver units, respectively, to supply the measurement unit, which includes a heart rate sensor, microcontroller, and wireless protocol (nRF24L01) with the operating voltage. The experimental results found that an adequate voltage of 5 V was achieved by the power component to operate the measurement unit at a 20 cm air gap between the receiver and transmitter coils. Further, the measurement accuracy of the WHR was 99.65% comparative to the benchmark (BM) instrument. Moreover, the measurements of the WHR were validated based on statistical analyses. The results of this study are superior to those of leading works in terms of measurement accuracy, power transfer, and Transfer efficiency.

scholarly journals Differential Evolution in Waveform Design for Wireless Power Transfer

Telecom ◽  
2020 ◽  
Vol 1 (2) ◽  
pp. 96-113
Author(s):  
Pavlos Doanis ◽  
Achilles Boursianis ◽  
Julien Huillery ◽  
Arnaud Bréard ◽  
Yvan Duroc ◽  
...  
Keyword(s):  
Power Efficiency ◽  
Optimization Problem ◽  
Nonlinear Behavior ◽  
Wireless Power Transfer ◽  
Waveform Design ◽  
Optimal Solutions ◽  
Power Transfer ◽  
Wireless Power ◽  
Single Input Single Output ◽  
Single Output

The technique of transmitting multi-tone signals in a radiative Wireless Power Transfer (WPT) system can significantly increase its end-to-end power efficiency. The optimization problem in this system is to tune the transmission according to the receiver rectenna’s nonlinear behavior and the Channel State Information (CSI). This is a non-convex problem that has been previously addressed by Sequential Convex Programming (SCP) algorithms. Nonetheless, SCP algorithms do not always attain globally optimal solutions. To this end, in this paper, we evaluate a set of Evolutionary Algorithms (EAs) with several characteristics. The performance of the optimized multi-tone transmission signals in a WPT system is assessed by means of numerical simulations, utilizing a simplified Single Input Single Output (SISO) model. From the model evaluation, we can deduce that EAs can be successfully applied to the waveform design optimization problem. Moreover, from the presented results, we can derive that EAs can obtain the optimal solutions in the tested cases.

A Review of Methods and Challenges for Improvement in Efficiency and Distance for Wireless Power Transfer Applications

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Sokol Kuka ◽  
Kai Ni ◽  
Mohammed Alkahtani
Keyword(s):  
Electric Vehicles ◽  
Power Efficiency ◽  
Near Field ◽  
Electronic Devices ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Inductive Power Transfer ◽  
The Past ◽  
Transmission Distance

AbstractOver the past few years, interest and research in wireless power transfer (WPT) have been rapidly incrementing, and as an effect, this is a remarkable technology in many electronic devices, electric vehicles and medical devices. However, most of the applications have been limited to very close distances because of efficiency concerns. Even though the inductive power transfer technique is becoming relatively mature, it has not shown near-field results more than a few metres away transmission. This review is focused on two fundamental aspects: the power efficiency and the transmission distance in WPT systems. Introducing the principles and the boundaries, scientific articles will be reviewed and discussed in terms of their methods and respective challenges. This paper also shows more important results in efficiency and distance obtained, clearly explaining the theory behind and obstacles to overcome. Furthermore, an overlook in other aspects and the latest research studies for this technology will be given. Moreover, new issues have been raised including safety and security.

scholarly journals Single-Tube and Multi-Turn Coil Near-Field Wireless Power Transfer for Low-Power Home Appliances

Energies ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1969 ◽  
Author(s):  
Aqeel Jawad ◽  
Rosdiadee Nordin ◽  
Sadik Gharghan ◽  
Haider Jawad ◽  
Mahamod Ismail ◽  
...  
Keyword(s):  
Low Power ◽  
Power Efficiency ◽  
Copper Wire ◽  
Near Field ◽  
Wireless Power Transfer ◽  
Battery Life ◽  
Total System ◽  
Power Transfer ◽  
Wireless Power ◽  
Single Tube

Single-tube loop coil (STLC) and multi-turn copper wire coil (MTCWC) wireless power transfer (WPT) methods are proposed in this study to overcome the challenges of battery life during low-power home appliance operations. Transfer power, efficiency, and distance are investigated for charging mobile devices on the basis of the two proposed systems. The transfer distances of 1–15 cm are considered because the practicality of this range has been proven to be reliable in the current work on mobile device battery charging. For STLC, the Li-ion battery is charged with total system efficiencies of 86.45%, 77.08%, and 52.08%, without a load, at distances of 2, 6, and 15 cm, respectively. When the system is loaded with 100 Ω at the corresponding distances, the transfer efficiencies are reduced to 80.66%, 66.66%, and 47.04%. For MTCWC, the battery is charged with total system efficiencies of 88.54%, 75%, and 52.08%, without a load, at the same distances of 2, 6, and 15 cm. When the system is loaded with 100 Ω at the corresponding distances, the transfer efficiencies are drastically reduced to 39.52%, 33.6%, and 15.13%. The contrasting results, between the STLC and MTCWC methods, are produced because of the misalignment between their transmitters and receiver coils. In addition, the diameter of the MTCWC is smaller than that of the STLC. The output power of the proposed system can charge the latest smartphone in the market, with generated output powers of 5 W (STLC) and 2 W (MTCWC). The above WPT methods are compared with other WPT methods in the literature.

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