Metamaterial-enhanced near-field readout platform for passive microsensor tags

Abstract

Radiofrequency identification (RFID), particularly passive RFID, is extensively employed in industrial applications to track and trace products, assets, and material flows. The ongoing trend toward increasingly miniaturized RFID sensor tags is likely to continue as technology advances, although miniaturization presents a challenge with regard to the communication coverage area. Recently, efforts in applying metamaterials in RFID technology to increase power transfer efficiency through their unique capacity for electromagnetic wave manipulation have been reported. In particular, metamaterials are being increasingly applied in far-field RFID system applications. Here, we report the development of a magnetic metamaterial and local field enhancement package enabling a marked boost in near-field magnetic strength, ultimately yielding a dramatic increase in the power transfer efficiency between reader and tag antennas. The application of the proposed magnetic metamaterial and local field enhancement package to near-field RFID technology, by offering high power transfer efficiency and a larger communication coverage area, yields new opportunities in the rapidly emerging Internet of Things (IoT) era.

Advancements in Passive Wireless Sensors, Materials, Devices, and Applications

“…In response to the requirement that passive wireless sensors can only be used in a narrow area, RFID sensors are miniaturized sensor networks that combine radio frequency identification technology (RFID) tag antennas with wireless sensor network technology (WSN) [24]. The main role of WSN is to obtain environmental information or send the internal information of the supervised object, and the role of RFID is to identify and monitor the monitored object [25,26]. RFID is a low-cost technology that enables passive wireless data communication.…”

Wireless, customizable coaxially shielded coils for magnetic resonance imaging

“…Capitalizing on the unique electromagnetic properties, coaxial cables have recently found applications in wireless non-radiative power transfer (36)(37)(38)(39). They exhibit remarkable magnetic responses by eliminating the electric dipole moment inherent in conventional helical coils commonly used for wireless power transfer (40,41). With respect to their application to MRI systems, the focus herein, recent advancements involve the utilization of coaxial cable in the development of surface coils (42).…”

Computational‐Design Enabled Wearable and Tunable Metamaterials via Freeform Auxetics for Magnetic Resonance Imaging

“…One notable property of metamaterials is near‐field enhancement. When excited by an incident wave at their resonance frequency, metamaterials generate an intense and localized electric field at the edges of their narrow capacitive gaps, as well as a magnetic field around the conductive or metallic structures, which has enabled their application to phase conjugation, [ 9 ] second‐harmonic generation, [ 10 ] high‐sensitivity sensing, [ 11 ] and wireless power transfer, [ 12 , 13 ] among others. Leveraging this unique magnetic field enhancement property, metamaterials, consisting of diverse arrays of unit cells featuring conducting “Swiss rolls”, parallel metallic wires, or helical coils, have been utilized to boost the signal‐to‐noise ratio (SNR) of the magnetic resonance imaging (MRI) by amplifying the radiofrequency (RF) magnetic field strength.…”