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 Â 10 À6 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 mm) 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.

Hydrogen storage, fullerene, LiBH 4 , nanocomposite, fullerane Reversible hydrogen storage in a LiBH 4 :C 60 nanocomposite (70:30 wt. %) synthesized by solvent-assisted mixing has been demonstrated. D uring the solvent-assisted mixing and nanocomposite formation, a chemical reaction occurs in which the C 60 cages are significantly modified by polymerization as well as by hydrogenation (fullerane formation) in the presence of LiBH 4 . We have determined that two distinct hydrogen desorption events are observed upon rehydrogenation of the material, which are attributed to the reversible formation of a fullerane (C 60 H x ) as well as a LiBH 4 species. This system is unique in that the carbon species (C 60 ) actively participates in the hydrogen storage process which differs from the common practice of 2 melt infiltration of high surface area carbon materials with LiBH 4 (nanoconfinment effect). This nanocomposite demonstrated good reversible hydrogen storage properties as well as the ability to absorb hydrogen under mild conditions (pressures as low as 10 bar H 2 or temperatures as low as 150°C). The nanocomposite was characterized by TGA-RGA, DSC, XRD, LDI-TOF-MS, FT-IR, 1 H NMR, and APPI MS.

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1. Introduction: Radio Frequency Identification (RFID) has found use in areas such as access control systems, point of sale, automatic toll collection, animal tracking, vehicle tracking and immobilization and also in the retail supply chain [1]. For medical applications, RFID technology can be used for patient tracking and safeguarding [2] as well as for equipment inventory management. RFID tags have also been used for physiological monitoring [3].The use of wireless monitoring in a hospital environment aims to improve the efficiency of patient care. Advances have seen the use of RFID technology as a standalone system or in combination with other wireless technologies [4]. Proposed battery-less wireless health sensors [5] will transmit patient vital data and therefore the risks associated with signal outage are high making it important to keep skin mounted RFID tag read failure to a minimum.Human tracking and monitoring can be achieved with RFID chips embedded in the skin [6] however this is very short read range and is inappropriate for non-permanent applications. Alternatively RFID wristbands [7] are widely used but must go on the wrist or ankle and offer only a loose contact to the skin which compromises their use for monitoring. For instance, it may not be optimal for physiological measurements such as heartbeat and pulse which require close skin contact [8]. The use of RFID for medical sensing has also been reported in works such as [9] where an adhesive sensor badge is reported for sensing biomarkers in sweat and in [10] for monitoring surface temperature.Diversity is a technique used in communication systems where alternative transmission mechanisms are introduced to reduce the chance of losing communication (signal outage). In RFID, the chances of successfully reading a tagged object or person are increased if more than one tag is used. This is referred to as tag diversity. In [11] a plaster operating over a few centimetres at the NFC frequency of 13.56 MHz was presented and in [12] the most efficient tag placement for two worn UHF tags communicating with an external reader was studied using 3 mm thick textile slotted patch antennas. The study indicated more than 2 tags of the slotted patch design were required to provide coverage all around the body. Other works such as [13] have sought to improve the performance of on-body RFID tags by using dual tag antenna diversity to reduce the probability of phase cancellation between the RFID reader continuous carrier wave and the backscattered signal from the tag. Diversity is already often implemented at the reader end and in [14] a non-RFID body mounted wireless system utilizes multiple antennas at the off-body base station. While this results in an improvement in outage, it will also lead to an increase in infrastructure

Abstract-Errors occur in the process of digital printing of frequency selective screens using conductive inks. This paper describes some of the defects observed during the printing process and investigates their effect on the resonance frequencies of arrays that might be fabricated in practice. The elements are simple linear dipoles. The presence of the classes of error described would be serious in the case of elements with complex geometries.

There is a strong and growing need for reliable, cost-effective grid storage to support a transition from fossil fuels. Non-aqueous redox-flow batteries (NRFB) are a promising technology to meet this need but they are currently limited by poor stability of solution-phase, charge-carrying metal complexes. A major mechanism of decomposition of these redox electrolytes is substitution of ligands that have weak interactions with substitution-labile metal ions. Presented herein is an approach to mitigate these thermodynamic and kinetic challenges with a naturally occurring compound that is produced biologically. Mushrooms of the genus Amanita synthesize a molecule known as Amavadin, in which a vanadium ion is tightly coordinated by a pair of 2,2’-(hydroxyimino)dipropionic acid (HIDPA) ligands. Millions of generations of evolution have optimized the stability of this molecule. As a result, under physiological conditions in which most vanadium compounds would decompose, ligand substitution is suppressed. The electrochemical properties of redox molecules based on Amavadin as NRFB electrolytes will be presented. This will include data on electrochemical reversibility and stability to deep redox-cycling under various conditions. In addition, we will present the results of computational investigations that have guided ligand-design efforts. These are focused on optimization of the properties of Amavadin-based compounds for application in energy storage devices without losing their extraordinary ability to bind metal ions.