Dumtoochukwu Oyeka

Inkjet printed paper based frequency selective surfaces and skin mounted RFID tags: the interrelation between silver nanoparticle ink, paper substrate and low temperature sintering technique

Inkjet printing of functional frequency selective surfaces (FSS) and radio frequency identification (RFID) tags on commercial paper substrates using silver nanoparticle inks sintered using low temperature thermal, plasma and photonic techniques is reported. Printed and sintered FSS devices demonstrate performances which achieve wireless communication requirements having a forward transmission scattering parameter, S21, depth greater than -20 dB at 13 GHz. Printed and plasma sintered RFID tags on transfer paper, which are capable of being mounted on skin, improved read distances compared to previously reported single layer transfer RFID tags fabricated by conventional thermal sintering. This journal is cop. The Royal Society of Chemistry 2015.

Towards inkjet-printed low cost passive UHF RFID skin mounted tattoo paper tags based on silver nanoparticle inks

The present work describes the inkjet printing and low temperature sintering of silver nanoparticle inks onto transfer tattoo paper. Our approach results in silver features of excellent resolution and conductivity and, subsequently the first passive UHF RFID transfer tattoo tags functional mounted on human skin of improved performance when compared to screen printed passive UHF RFID transfer tattoo paper tags. Moreover, inkjet printed passive UHF RFID transfer tattoo tags show similar performance to copper etched passive UHF RFID tags on plastic substrates. This study compares the image quality (resolution) and electrical performance of two commercial silver nanoparticle inks inkjet printed on transfer tattoo paper. The optimal printing and sintering parameters to obtain high resolution features of resistivities 20 to 57 times the resistivity of bulk silver (1.59 × 10−6 ohm cm) are described. We demonstrate how, by selectively depositing ink in specific areas of the antenna, read distance of passive UHF RFID tags can be increased from 54 to 68 cm whilst decreasing the amount of ink used by 33%. Furthermore, this approach results in inkjet printed passive UHF RFID tattoo tags with larger read distance than silver screen printed passive UHF RFID tattoo tags, 45 cm, and similar to copper etched passive UHF RFID plastic tags, 75 cm. Moreover, inkjet printed passive UHF RFID tattoo tags in this work are considerably thinner (1–5 μm) than screen and etched passive UHF RFID tags (tens of micrometers) hence, making the former more appealing to the end user. In addition to this, inkjet printing is compatible with large area manufacturing techniques and has the potential to evolve as one of the most promising RFID mass-production techniques. Therefore, this work represents a step towards the commercialization of on-body transfer tattoo paper passive UHF RFID tags.

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 skins 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 0.5i¾?m have been achieved with the tag only10i¾?µm from the body.

Developing inkjet printing to enable low cost UHF RFID transfer tattoo tags

This paper demonstrates the use of inkjet printing as a digital fabrication tool for the cost effective manufacture of radio frequency identification (RFID tags on low-cost flexible and porous substrates. The design presented in this work is a thin, substrate tolerant UHF RFID tag that can be mounted directly onto the skin surface in the form of a transfer patch in the same way that a temporary tattoo is applied.

Effect of skin dielectric properties on the read range of epidermal ultra-high frequency radio-frequency identification tags

This Letter presents an investigation of the effect of human tissue conductivity and permittivity on the performance of epidermal transfer tattoo ultra-high frequency radio-frequency identification (RFID) tags. The measurements were carried out on 20 individuals and the variations in the measured dielectric properties correlate well with variations in the measured tag read range on the individuals and to a lesser extent with their body mass index values. Simulation results also showed the effects of permittivity and conductivity on the designed resonance frequency of the RFID tag.

RFID sticking plasters

RFID tags are integrated into medical sticking plasters for future health monitoring applications. For compatibility with the skin, the tag is fabricated from conducting Electronylon material and is demonstrated to work with a useful read range when placed directly on the skin. For the purposes of this study, a useful read range was defined as more than 50cm.

Enhanced read range Tattoo RFID tags

Transfer Tattoo RFID tags are described for person locating scenarios. The technology considered is Radio Frequency Identification (RFID) at the UHF Band where it is possible to obtain wireless connection over distances of several meters using passive, or battery assisted transfers. The tags have the profile of tattoos and can be mounted straight onto the skin. Promising results for enhancing read distances, possibly to tens of meters, have been obtained using very thin battery technologies.