Durability of Wearable Antennas Based on Nonwoven Conductive Fabrics: Experimental Study on Resistance to Washing and Ironing

Adhesive nonwoven conductive fabrics are appealing materials for fabricating fully textile antennas for wearable wireless systems. Wearable antennas should be flexible, lightweight, and mechanically resistant. Additionally, the antenna performance should be robust to activities related to daily use of garments, such as washing and ironing. Accordingly, in this work, the results of several washing tests performed on fully textile antennas fabricated by exploiting three different adhesive nonwoven conductive fabrics are reported

Tutela multilivello delle specie protette e degli habitat

Lo scopo che mi sono preposta con questo lavoro è quello di effettuare un' analisi multilivello sulla tutela della biodiversità, arrivando ad individuare in che modo siano attualmente tutelate le specie e gli habitat a livello internazionale, comunitario e nazionale, quali siano gli strumenti utilizzati e se questi siano o meno sufficienti. Ho appurato come sia mutata con il tempo l' importanza assunta dalla biodiversità nei vari livelli, in particolare a livello internazionale con la Carta mondiale della Natura del 1982, la quale ha espresso una visione prettamente ecosistemica, con la Dichiarazione di Stoccolma del 1972 e con Convenzione di Rio su ambiente e sviluppo del 1992 la quale ha introdotto delle forme di tutela per la biodiversità. Di rilevante importanza risulta essere anche la Convenzione CITES del 1973, la quale rappresenta il primo e unico strumento per la tutela del commercio di specie di fauna e flora protette. A livello comunitario, sulla scia di ciò che è avvenuto a livello internazionale, a partire dagli anni ' 70 è stata posta una sempre più crescente attenzione alla tutela delle sepcie e degli habitat, in modo particolare ho analizzato la direttiva Uccelli 79/409 CE, e la direttiva Habitat 92/43 CE la quale ha il merito di aver regolamentato la Rete Natura 2000 e la procedura di valutazione d' incidenza. Infine, ho posto l' attenzione al livello nazionale, e ho studiato come tali atti siano stati recepiti nel nostro ordinamento e come l' Italia, sebbene in ritardo rispetto ai livelli superiori, si stia sforzando per una corretta tutela delle specie e degli habitat tramite un abbandono della visione antropocentrica della Natura e un progressivo avvicinamento ad una visione ecosistemica

A Network Approach for Wireless Resonant Energy Links Using Relay Resonators

In this paper, a network approach for the analysis of a wireless resonant energy link consisting of N inductively coupled LC resonators is proposed. By using an artificial transmission line approach, the wireless link is modeled as a transmission line described by effective parameters. It is shown that the analyzed system exhibits a passband filter behavior. More specifically, the reported results demonstrate that in the wireless link passband the effective parameters assume negative values resulting in a negative phase delay. Useful design formulas are derived and validated by comparisons with the experimental data

Wireless resonant energy link for pulse generators implanted in the chest

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A Wearable Wireless Energy Link for Thin-Film Batteries Charging

A wireless charger for low capacity thin-film batteries is presented. The proposed device consists of a nonradiative wireless resonant energy link and a power management unit. Experimental data referring to a prototype operating in the ISM band centered at 434 MHz are presented and discussed. In more detail, in order to facilitate the integration into wearable accessories (such as handbags or suitcases), the prototype of the wireless energy link was implemented by exploiting a magnetic coupling between two planar resonators fabricated by using a conductive fabric on a layer of leather. From experimental data, it is demonstrated that, at 434 MHz, the RF-to-RF power transfer efficiency of the link is approximately 69.3%. As for the performance of the system as a whole, when an RF power of 7.5 dBm is provided at the input port, a total efficiency of about 29.7% is obtained. Finally, experiments performed for calculating the charging time for a low capacity thin-film battery demonstrated that, for RF input power higher than 6 dBm, the time necessary for recharging the battery is lower than 50 minutes

Wearable Antennas for Remote Health Care Monitoring Systems

Remote monitoring of the elderly in telehealth applications requires that the monitoring must not affect the elderly's regular habits. To ensure this requirement, the components (i.e., sensor and antenna) necessary to carry out such monitoring should blend in with the elderly's daily routine. To this end, an effective strategy relies on employing wearable antennas that can be fully integrated with clothes and that can be used for remotely transmitting/receiving the sensor data. Starting from these considerations, in this work, two different methods for wearable antenna fabrication are described in detail: The first resorts to the combined use of nonwoven conductive fabrics and of a cutting plotter for shaping the fabric, whereas the second considered fabrication method resorts to the embroidery of conductive threads. To demonstrate the suitability of the considered fabrication techniques and to highlight their pros and cons, numerical and experimental results related to different wearable antennas are also reported and commented on. Results demonstrate that the presented fabrication techniques and strategies are very flexible and can be used to obtain low-cost wearable antennas with performance tailored for the specific application at hand

Logo antenna on textile materials

This paper presents a novel logo-shaped antenna. The proposed antenna has been fabricated by using a conductive non-woven textile on a layer of jeans. Experimental data referring to a prototype working at 1.8 GHz are presented and compared with numerical results. A relative bandwidth of about 70% and a dipole-like radiation pattern is demonstrated

Textile logo antennas

Two novel textile antennas are presented in this paper. The geometry of the two antennas has been shaped so to mimic the logo of two popular companies: the French clothing company LACOSTE and the American multinational corporation APPLE Inc. Two prototypes fabricated by using a conductive non-woven textile on a layer of jeans are presented. Both prototypes were optimized to work at 1.8 GHz. From experimental data excellent performance are demonstrated

A wearable wireless energy link

This paper presents a wireless energy link for wearable applications. The proposed link exploits a magnetic coupling between two resonators fabricated by using a conductive non-woven fabric for the conductive parts and leather as substrate, thus resulting in a prototype that can be easily embedded in wearable accessories such as fashion bags. Experimental data referring to a prototype working in the ISM band (433.05 - 434.79 MHz) demonstrate a power transfer efficiency of about 69 %

A Frequency Signature RFID Chipless Tag for Wearable Applications

In this paper, a frequency-signature Radio-Frequency Identification (RFID) chipless tag for wearable applications is presented. The results achieved for a fully-textile solution guaranteeing a seamless integration in clothes are reported and discussed. The proposed tag consists of two planar monopole antennas and a 50 Ω microstrip line loaded with multiple resonators. In order to achieve a compact size, the resonators are slotted on the ground plane of the microstrip line. As for the antennas, the same geometry was exploited for both the TX and the RX tag antenna. In particular, it consists of a proximity fed planar monopole on a ground plane. The selected geometry guarantees easy integration with the multi-resonator structure. Numerical and experimental data referring to a 2-bit implementation are presented and discussed. For fabricating all the prototypes, a layer of pile was used as a substrate, while an adhesive non-woven conductive fabric was exploited for the fabrication of the conductive parts. Experimental tests demonstrate that although the performance of the final device strongly depends on the properties of the used materials and on the imperfections of the fabrication process, the proposed frequency-signature RFID chipless tag is suitable for wearable applications, such as anti-counterfeiting systems and laundry labels