Battery-free Radio Frequency Identification Research Articles

GQM: Autonomous goods quantity monitoring in IIoT based on battery-free RFID

With the rapid development of science and technology, the Industrial Internet of Things (IIoT) has been improving and developing continuously since it was put forward, and the traditional industry has gradually moved towards networking and intellectualization. In the past, it was necessary to attach a radio frequency identification (RFID) label to each goods to complete the quantity monitoring, or to complete the counting by manpower. But the Radio Frequency Identification tags cannot be recycled, which will generate a lot of e-waste or increasing the cost of manpower. Therefore, in order to reduce the use of Radio Frequency Identification tags in practical applications, it is necessary to explore an innovative quantity monitoring system. We use the relationship between the quantity of goods and the digital signal to collect and analyze the data and information, and then to collect statistical data and real-time feedback information. The ultimate goal is to realize the intelligent management of goods in factory warehouse. In this paper, we propose a goods quantity monitoring system in a small warehouse. Firstly, we extract Radio Frequency (RF) signals in static and dynamic scene and preprocess them. Then, we extract the corresponding features according to different situations. Finally, we identify the quantity of goods according to K-Nearest Neighbors (KNN) classification algorithm. We have done a lot of experiments with Radio Frequency Identification equipment. The experimental results show that our system is robust and the average recognition accuracy reaches 95.53%.

Low‐power ultra‐wide band pulse generator based on a PIN diode

Radio-frequency identification (RFID) tags (passive kind) are typically not designed to include ultra-wide band (UWB) pulse generators, but may be in the future. The reason is that the very short pulses produced by the RFID tags could be used to estimate their positions with errors of solely a few centimetres using time difference of arrival techniques. Currently, the method most commonly used to estimate tag positions relies on received signal strengths (less accurate). An UWB pulse generator based on a PIN diode is presented in this study. This pulse generator was designed to produce a positive unipolar pulse for each high-to-low transition (1.8 V to 0) it receives at its input. This trigger signal is generated by a microntroller-based battery-free RFID tag. The end result is a pulse with an amplitude of ∼300 mV and a duration of slightly <2 ns measured using a 50 Ω load.

Battery-free Radio Frequency Identification (RFID) Sensors for Food Quality and Safety

Market demands for new sensors for food quality and safety stimulate the development of new sensing technologies that can provide an unobtrusive sensor form, battery-free operation, and minimal sensor cost. Intelligent labeling of food products to indicate and report their freshness and other conditions is one important possible application of such new sensors. This study applied passive (battery-free) radio frequency identification (RFID) sensors for the highly sensitive and selective detection of food freshness and bacterial growth. In these sensors, the electric field generated in the RFID sensor antenna extends from the plane of the RFID sensor and is affected by the ambient environment, providing the opportunity for sensing. This environment may be in the form of a food sample within the electric field of the sensing region or a sensing film deposited onto the sensor antenna. Examples of applications include monitoring of milk freshness, fish freshness, and bacterial growth in a solution. Unlike other food freshness monitoring approaches that require a thin film battery for operation of an RFID sensor and fabrication of custom-made sensors, the passive RFID sensing approach developed here combines the advantages of both battery-free and cost-effective sensor design and offers response selectivity that is impossible to achieve with other individual sensors.

Multivariable passive RFID vapor sensors: roll-to-roll fabrication on a flexible substrate

We demonstrate roll-to-roll (R2R) fabrication of highly selective, battery-free radio frequency identification (RFID) sensors on a flexible polyethylene terephthalate (PET) polymeric substrate. Selectivity of our developed RFID sensors is provided by measurements of their resonance impedance spectra, followed by the multivariate analysis of spectral features, and correlation of these spectral features to the concentrations of vapors of interest. The multivariate analysis of spectral features also provides the ability for the rejection of ambient interferences. As a demonstration of our R2R fabrication process, we employed polyetherurethane (PEUT) as a "classic" sensing material, extruded this sensing material as 25, 75, and 125-μm thick films, and thermally laminated the films onto RFID inlays, rapidly producing approximately 5000 vapor sensors. We further tested these RFID vapor sensors for their response selectivity toward several model vapors such as toluene, acetone, and ethanol as well as water vapor as an abundant interferent. Our RFID sensing concept features 16-bit resolution provided by the sensor reader, granting a highly desired independence from costly proprietary RFID memory chips with a low-resolution analog input. Future steps are being planned for field-testing of these sensors in numerous conditions.