Efficient Distributed Wireless Power Transfer System for Multiple Wearable Sensors through Textile Coil Array

Abstract

When it is necessary to detect various physiological signals of the human body, clothing embroidered with near-field effect patterns can be used as a long-term power supply medium to supply power to long-distance transmitters and receivers to form a wireless power supply system. The proposed system uses an optimized parallel circuit to achieve a power transfer efficiency of more than five times higher than that of the existing series circuit. The power transfer efficiency of simultaneously supplying energy to multiple sensors is increased higher than five times and even more when only one sensor is coupled. When powering eight sensors at the same time, the power transmission efficiency can reach 25.1%. Even when eight sensors powered by the coupled textile coils are reduced to one, the power transfer efficiency of the whole system can reach 13.21%. Additionally, the proposed system is also applicable when the number of sensors ranges from 2 to 12.

Multi-Resonator Wireless Inductive Power Link for Wearables on the 2D Surface and Implants in 3D Space of the Human Body

“…Magnetic resonance-based WPT (MR-WPT) technology, incorporating multi-coil (resonator) with various configurations, has emerged as an efficient and widely adopted solution for powering implants and wearable devices. Recent studies have aimed to expand the transfer distance, extend the effective 3D coverage area, adhere to safety standards, and enhance adaptability [36]- [42]. Different multi-coil Tx array configurations, namely switching approaches, floating resonators, parallel resonators, overlapping designs, two sandwiched structures, and so on, have been proposed to increase the effective active area where that implant or wearable devices can receive sufficient power [6], [36]- [42].…”

“…Recent studies have aimed to expand the transfer distance, extend the effective 3D coverage area, adhere to safety standards, and enhance adaptability [36]- [42]. Different multi-coil Tx array configurations, namely switching approaches, floating resonators, parallel resonators, overlapping designs, two sandwiched structures, and so on, have been proposed to increase the effective active area where that implant or wearable devices can receive sufficient power [6], [36]- [42]. In floating, switching, and overlapping states, a disconnected array may lead to multiple resonance frequency peaks [38]- [40], [41], [43], [44].…”

Model-Based Optimization of Spiral Coils for Improving Wireless Power Transfer

“…The coil quality factor at the operating frequency ω is determined, as shown in Equation (3), as the ratio between the coil self-inductance (L coil ) and the coil internal resistance R coil . The coil self-inductance and internal resistance depend on the coil geometry and materials used.…”

“…In recent years, the use of Inductive Power Transfer (IPT) has increased in many applications where cables are not desired or cannot be used, such as medical implants [1], wireless sensor nodes [2], smart textile wearable devices [3], electrical vehicles [4], and robots [5]. Typically, IPT systems are based on coupled-mode theory in an oscillating electromagnetic field with a transmitter coil (TX) and a receiver coil (RX), respectively.…”

Advances and Development of Electronic Neural Interfaces

“…Several indicators, such as heart rate, body temperature, and even muscle and brain activity, may be tracked using wearable sensors. Li, Lee, Lim, and Lee [21]present a flexible, wearable system that combines a ZnIn2S4nanosheet-centric humidity sensors and carbon nanotudes/Sn02 sensors for temperature. This system has been effectively assessed on a healthy volunteer to research on the thermo-regulatory feedback to cold exercises and stimulations, with the goal of developing a method for early forecasts of thermoregulation disorders [26], [27], [28].…”