Effects of the Human Body on Wearable Wireless Power Transfer Systems

2021 ◽  
Vol 35 (11) ◽  
pp. 1454-1455
Author(s):  
Gianfranco Perez-Greco ◽  
Juan Barreto ◽  
Abdul-Sattar Kaddour ◽  
Stavros Georgakopoulos
Keyword(s):  
Human Body ◽  
Material Properties ◽  
Wireless Power Transfer ◽  
Power Transfer ◽  
Wireless Power ◽  
Strongly Coupled ◽  
Power Transfer Efficiency ◽  
Different Shapes ◽  
System Operating ◽  
Different Parts

In this paper, the effects of different parts of the human body on a wearable Wireless Power Transfer (WPT) system are examined. A Strongly Coupled Magnetic Resonators (SCMR) WPT system operating in the ISM band 40.68 MHz is used in this study. The results show that when the WPT system is placed directly on the human body its Power Transfer Efficiency (PTE) is reduced by 13% on average in both simulations and measurements. These losses are attributed to the material properties of the human body. Also, different parts of the human body cause different drops in PTE due to their different shapes and geometries.

scholarly journals Maximizing Transfer Efficiency with an Adaptive Wireless Power Transfer System for Variable Load Applications

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1417
Author(s):  
Jung-Hoon Cho ◽  
Byoung-Hee Lee ◽  
Young-Joon Kim
Keyword(s):  
Loading Condition ◽  
Wireless Power Transfer ◽  
Input Voltage ◽  
Transfer Efficiency ◽  
Maximum Efficiency ◽  
Variable Load ◽  
Power Transfer ◽  
Wireless Power ◽  
Variable Loading ◽  
Power Transfer Efficiency

Electronic devices usually operate in a variable loading condition and the power transfer efficiency of the accompanying wireless power transfer (WPT) method should be optimizable to a variable load. In this paper, a reconfigurable WPT technique is introduced to maximize power transfer efficiency in a weakly coupled, variable load wireless power transfer application. A series-series two-coil wireless power network with resonators at a frequency of 150 kHz is presented and, under a variable loading condition, a shunt capacitor element is added to compensate for a maximum efficiency state. The series capacitance element of the secondary resonator is tuned to form a resonance at 150 kHz for maximum power transfer. All the capacitive elements for the secondary resonators are equipped with reconfigurability. Regardless of the load resistance, this proposed approach is able to achieve maximum efficiency with constant power delivery and the power present at the load is only dependent on the input voltage at a fixed operating frequency. A comprehensive circuit model, calculation and experiment is presented to show that optimized power transfer efficiency can be met. A 50 W WPT demonstration is established to verify the effectiveness of this proposed approach.

Wireless Power Transfer Systems via Strong Coupled Magnetic Resonances — Design, PCB Implementation and Tests

2011 ◽  
Vol 383-390 ◽  
pp. 5984-5989
Author(s):  
Yan Ping Yao ◽  
Hong Yan Zhang ◽  
Zheng Geng
Keyword(s):  
Printed Circuit Board ◽  
Experimental System ◽  
Wireless Power Transfer ◽  
Circuit Board ◽  
Transfer Efficiency ◽  
Power Transfer ◽  
Wireless Power ◽  
Power Transfer Efficiency ◽  
Coil Winding ◽  
Magnetic Resonances

In this paper, we present theoretical analysis and detailed design of a class of wireless power transfer (WPT) systems based on strong coupled magnetic resonances. We established the strong coupled resonance conditions for practically implementable WPT systems. We investigated the effects of non-ideal conditions presented in most practical systems on power transfer efficiency and proposed solutions to deal with these problems. We carried out a design of WPT system by using PCB (Printed Circuit Board) antenna pair, which showed strong coupled magnetic resonances. The innovations of our design include: (1) a new coil winding pattern for resonant coils that achieves a compact space volume, (2) fabrication of resonant coils on PCBs, and (3) integration of the entire system on a pair of PCBs. Extensive experiments were performed and experimental results showed that our WPT system setup achieved a guaranteed power transfer efficiency 14% over a distance of two times characteristic length(44cm). The wireless power transfer efficiency in this PCB based experimental system was sufficiently high to lighten up a LED with a signal generator.

scholarly journals Tuning of a wireless power transfer system with a hybrid capacitor array

2016 ◽  
Vol 3 (1) ◽  
pp. 9-14
Author(s):  
Nurcan Keskin ◽  
Huaping Liu
Keyword(s):  
Resonant Frequency ◽  
Hybrid Model ◽  
Wireless Power Transfer ◽  
Transfer System ◽  
Power Transfer ◽  
Wireless Power ◽  
Loosely Coupled ◽  
Capacitor Array ◽  
Power Transfer Efficiency ◽  
Wireless Power Transfer System

Power transfer efficiency in loosely coupled inductive systems can be enhanced by resonance. Primary and secondary can be tuned to same resonant frequency. In this paper, MOSFET-based Varactors and switchable capacitors are used for re-tuning of such a system at 13.56 MHz. This is achieved either using each cap structure alone or as a hybrid model. These techniques are designed for 13.56 MHz wireless power transfer system.

scholarly journals Wireless Charger for Artificial Pacemaker

2021 ◽  
Author(s):  
Abinaya.B ◽  
Abirami.A.P ◽  
Divya.J ◽  
Rajalakshmi.R
Keyword(s):  
Output Voltage ◽  
Wireless Power Transfer ◽  
The Body ◽  
Rechargeable Battery ◽  
Medical Procedure ◽  
Power Transfer ◽  
Wireless Power ◽  
Inductive Power Transfer ◽  
Voltage Controller ◽  
Power Transfer Efficiency

The vast majority of the modernized implantable devices and Bio-sensors are set inside a patient’s body. To overcome this constraint, in this paper we have designed a rechargeable battery with wireless power transfer technique. The transdermal power transfer for the Pacemaker which is placed inside the heart should be possible by the concept of mutual inductance. The receiver loop ought to be situated inside the body and the transmitter curl ought to be situated outside of the body. The voltage controller will give or manage the necessary yield (output) voltage. The experiments were conducted on wireless charging through pork tissues reveal that from a 3.919-mw power source, 3.072-mw power can be received at 300kHz, reaching a high wireless power transfer efficiency of 78.4%, showing that the charging is very fast. We have also connected a Bluetooth Module to the Atmega328 microcontroller. This Bluetooth technology is used in the Android mobile application to notice the charging levels of the pacemaker. This Inductive power transfer technique takes out the danger of contamination which is brought about by the medical procedure.

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