Through-Metal-Wall Power Delivery and Data Transmission for Enclosed Sensors: A Review

Abstract

The aim of this review was to assess the current viable technologies for wireless power delivery and data transmission through metal barriers. Using such technologies sensors enclosed in hermetical metal containers can be powered and communicate through exterior power sources without penetration of the metal wall for wire feed-throughs. In this review, we first discuss the significant and essential requirements for through-metal-wall power delivery and data transmission and then we: (1) describe three electromagnetic coupling based techniques reported in the literature, which include inductive coupling, capacitive coupling, and magnetic resonance coupling; (2) present a detailed review of wireless ultrasonic through-metal-wall power delivery and/or data transmission methods; (3) compare various ultrasonic through-metal-wall systems in modeling, transducer configuration and communication mode with sensors; (4) summarize the characteristics of electromagnetic-based and ultrasound-based systems, evaluate the challenges and development trends. We conclude that electromagnetic coupling methods are suitable for through thin non-ferromagnetic metal wall power delivery and data transmission at a relatively low data rate; piezoelectric transducer-based ultrasonic systems are particularly advantageous in achieving high power transfer efficiency and high data rates; the combination of more than one single technique may provide a more practical and reliable solution for long term operation.

Experimental RF-signal based wireless energy transmission

“…The technique is promising in applications such as wireless mobile device chargers or electric car chargers, where the physical size of the coils are not a major limiting factor and where the mutual position of the devices are not assumed to change drastically. Another substantial problem which somewhat limits the use of inductive solutions especially in industrial applications is the negative effect the presence of conductive materials between the coils may have on the energy transfer performance [10].…”

An Ultrasonic Through-Metal-Wall Power Transfer System with Regulated DC Output

“…So, ultrasound has been suggested as effective means for passing power, as well as data, through metal barriers without physical penetration [3][4][5]. Ultrasound has also been demonstrated capable of safely and efficiently transferring energy through human tissue to power deeply implanted medical devices [6][7][8][9].…”

Study on energy transmission through metal wall based on piezoelectric material

“…With the disadvantages of feed-through wires, it proposed a great challenge to the energy supply system and the technology of transmitting energy through metal wall has become a hotspot. Under the influence of the Faraday shielding [1], traditional wireless electromagnetic energy could not transmit through metal barriers with no decay [2]. An alternative approach to transmit electric energy is ultrasonic which has perfect performance when through solid wall even it's a metal wall [3].…”