Tamper Proof RFID Security Tag

In this publication we present a tamper proof long range platform tolerant uhf smart RFID tag to identify valuable or security sensitive products. The smart tag functions as platform tolerant tag but once detached from the host object, it will permanently stop to function buy rendering the RFID chip unusable. The tag substrate design for additive manufacturing, platform tolerant antenna design as well as electromagnetic performance and read range are provided

Passive UHF RFID Tilt Sensor

In this paper we introduce a bio-axis passive wireless UHF RFID tilt sensor for applications such as to increase safety in warehouse environment and damage detection in consumer goods and where long term monitoring of the product is essential without the need to supply power to the sensors. Simulation and prototype testing indicate it is possible to detect and isolate tilting in 3 axes

Smart radio-frequency identification tag for diaper moisture detection

A passive smart tag is described that responds to dampness in diapers once a pre-defined threshold value is reached. A high-frequency (HF) system at 13.56 MHz is used as this allows operation through water or human tissues with less absorption that would occur for an ultra-HF signal. A circular spiral coil and swelling substrate facilitate a reaction to dampness that can be detected without contact to the diaper wearer. A prototype design is simulated and measured results are provided together with a demonstration of a tag integrated into a worn diaper

Epidermal UWB RFID Tag for Application On-Skin

UHF RFID tags have been demonstrated as transfer tattoos on-skin [1]. However, the performance of these designs are limited owing to their very close proximity to highly lossy tissues which makes them unsuited for application in dense environments required in many sensitive tracking and identification applications, because of the inherent high power narrow band requirements of UHF RFID. Conversely, many proposed high resolution internal location systems use Impulse Radio Ultra-Wideband (IR-UWB) transmission with narrow RF pulses of a few hundred picoseconds spread over several GHz of bandwidth and with a power spectral density in the noise floor. These low spectral power density pulses are very difficult to detect and almost invisible to unauthorized readers as UWB pulses are indistinguishable from the noise, and can be detected only by receivers using correlation [2]. UWB RFID tags have been shown in location systems to offer fine temporal and spatial resolution, with cm level accuracy in both outdoor and indoor localization in all three dimensions [3]

Inkjet Fabrication of Frame Dipole FSS

Digital fabrication techniques gives the possibility of producing elements with very thin and precise features which could allow the modification of UHF structures to reduce ink usage while still achieving similar performance. This paper investigates the case where dipole elements are modified into Frame Dipoles by removing areas where the surface current tends to be very low

Tattoo Antenna Temporary Transfers Operating On-Skin (TATTOOS)

This paper discusses the development of RFID logo antennas based on the logos of Loughborough University and the University of Kent which can be tattooed directly onto the skin’s surface. Hence, this paper uses aesthetic principles to create functional wearable technology. Simulations of possible designs for the tattoo tags have been carried out to optimize their performance. Prototypes of the tag designs were fabricated and read range measurements with the transfer tattoos on a volunteers arm were carried out to test the performance. Measured Read ranges of approximately 0.5 m have been achieved with the antenna 10 µm from the body

Tilt and Tamper Sensing UHF RFID Security Tag

A passive tag is proposed for indicting mishandling of items in the supply chain. The tag signals excessive tilting by varying its read range and as a measure against counterfeiting, it is deactivated should it be removed from its original platform

Supply Chain Integrity Tilt Sensing RFID Tag

A tilt sensing tag is presented with a passive wireless RFID communications link. The tag is designed to reduce its read range when tilted in order to signal and memorize mishandling during transit or storage. The novelty of this design is the incorporation of mechanically altered ground plane separation from the antenna to achieve 2 states of input match, and also the introduction of a pair of sensing pads connected directly to the antenna port to facilitate the tilt detection and the retention of that information. The significance is for supply chain integrity with the realization of low cost wireless sensing tags that can be deployed widely in the monitoring of objects using standard RFID transponder chips, without the need of continuous energy harvesting, on-tag batteries or super capacitors. The results show that, when mounted on a variety of platforms, the tags are able to detect and retain tilt events by signalling states through backscattered power levels. The mechanical structure of the tag is proposed for manufacture by new additive printing techniques

Ionic Push–Pull Polythiophenes: A Further Step towards Eco-Friendly BHJ Organic Solar Cells

Four new conjugated polymers alternating benzothiadiazole units and thiophene moieties functionalized with ionic phosphonium or sulfonic acid salts in the side chains were synthesized by a postfunctionalization approach of polymeric precursors. The introduction of ionic groups makes the conjugated polymers soluble in water and/or polar solvents, allowing for the fabrication of bulk heterojunction (BHJ) solar cells using environmentally friendly conditions. All polymers were fully characterized by spectroscopic, thermal, electrochemical, X-ray diffraction, scanning electron, and atomic force techniques. BHJ solar cells were obtained from halogen-free solvents (i.e., ethanol and/or anisole) by blending the synthesized ionic push–pull polymers with a serinol-fullerene derivative or an ionic homopolymer acting as electron-acceptor (EA) or electron-donor (ED) counterparts, respectively. The device with the highest optical density and the smoothest surface of the active layer was the best-performing, showing a 4.76% photoconversion efficiency

Significant Factors in the Inkjet Manufacture of Frequency Selective Surfaces

Additive fabrication of electromagnetic structures by inkjet printing technology is both cost effective and compatible with a wide range environmentally-friendly substrates, enabling fabrication of frequency selective surface arrays with line dimensions less than 0.1 mm; difficult to achieve with conventional subtractive techniques. Several approaches have been investigated in order to produce low-cost frequency selective panels with acceptable level of isolation, such as savings in ink by depositing it at the edges of dipole elements where the surface current tends to maximize. The FSS transmission characteristics were improved by jetting multiple ink layers on the whole elements and at the edges. The electrical resistance of various arrays have been measured and analysed and has been used to assess the performances of the FSS