Numerical Assessment of Specific Absorption Rate in the Human Body Caused by NFC Devices

Wireless and battery-free technologies for neuroengineering

“…In practical applications, 13.56 MHz (wavelength of ~12 m) represents an attractive choice of frequency because its absorption by biological tissues lies within an acceptable range 175 (Table 1) and because it aligns with standards in RF identification and near-field communication (NFC) 104 . In addition, communication can be implemented along with power transfer at the same carrier frequency to allow for wireless control and data transmission using NFC protocols 176,177 .…”

“…Another advantage of magnetic resonant coupling is its low SAR 175 , which follows from the approximate power-law relationship of this quantity with relatively low frequencies (from hundreds of kHz to tens of MHz; ref. 165 ) used in magnetic resonant coupling.…”

Wireless Battery-free and Fully Implantable Organ Interfaces

“…Near-field power transfer exploits nonradiative EM energy at short distances from the transmitter (>λ) and relies on inductive coupling between the transmitting and receiving coils with transmission frequencies ranging from 100 kHz to 200 MHz . This modality allows for efficient WPT over short distances with an abundance of complementary infrastructure to support use with existing IoT devices. − The range of this modality is generally limited to a few centimeters, which can limit functionality for implantable systems; however, recent work has demonstrated transmission distances in arenas of 1 m 2 . , Devices utilizing capacitor banks and resonator antennas have been able to significantly improve transmission distance and power throughput. , Due to its nonradiative nature, magnetic resonant coupling (MRC) provides robust operation with low tissue adsorption and insensitivity to dielectric obstacles. The power-transfer efficiency of MRC is determined by the coupling coefficient, κ, between the primary and secondary coils, as well as by their Q-factors (see Figure a).…”

“…108,331 Devices utilizing capacitor banks 108 and resonator antennas have been able to significantly improve transmission distance and power throughput. 332,333 Due to its nonradiative nature, magnetic resonant coupling (MRC) provides robust operation with low tissue adsorption 334 and insensitivity to dielectric obstacles. The power-transfer efficiency of MRC is determined by the coupling coefficient, κ, between the primary and secondary coils, as well as by their Q-factors (see Figure 9a).…”

Low Power Wake-up Signaling for Dense Sensor Networks

“…We have no logical interpretation since we expected that it will have no effect according to the ability of magnetic field lines to penetrate objects. testing the human body since each organ has different specific absorption rate (SAR) [24].…”