E-Textile embroidered metamaterial transmission line for signal propagation control

In this paper, the utilization of common fabrics for the manufacturing of e-textile metamaterial transmission lines is investigated. In order to filter and control the signal propagation in the ultra-high frequency (UHF) range along the e-textile, a conventional metamaterial transmission line was compared with embroidered metamaterial particles. The proposed design was based on a transmission line loaded with one or several split-ring resonators (SRR) on a felt substrate. To explore the relations between physical parameters and filter performance characteristics, theoretical models based on transmission matrices’ description of the filter constituent components were proposed. Excellent agreement between theoretical prediction, electromagnetic simulations, and measurement were found. Experimental results showed stop-band levels higher than −30 dB for compact embroidered metamaterial e-textiles. The validated results confirmed embroidery as a useful technique to obtain customized electromagnetic properties, such as filtering, on wearable applications.Postprint (published version

Split square resonators using high dielectric constant

This paper reports the design of a split ring resonator bandpass filter. The design is based on coupling coefficient filter and the novelty of the proposed design is possibility to miniaturize the structure by including a new kind of dielectric resonator fabricated with a commercial high dielectric constant EPOXY paste. Equivalent circuit model is discussed, establishing a clear relation between each component and physical parameter of the proposed design. Excellent agreement between electromagnetic simulation and measured of band pass filter at 1.65 GHz is found.Postprint (author's final draft

E-textile metamaterials: stop band pass filter

In this paper, the utilization of common fabrics for the manufacturing of e-textile metamaterial is investigated. The proposed design is based on a transmission line loaded with split-ring resonators (SRRs) on a cotton substrate for filter signal application. The proposed design provides a stop band between 2.7 GHz and 4.7 GHz, considering a four stage SRR topology. Experimental results showed stop band levels higher than -30 dB for the proposed compact embroidered metamaterial e-textiles. The validated results confirmed embroidery as a useful technique to obtain customized electromagnetic filter properties, such as transmitted signal filtering and control, on wearable tech device applications.This work was supported by the Ministry of Economy, Industry and Competitiveness under project TEC2016-79465-R.Peer ReviewedPostprint (published version

Effect of smart textile metamaterials on electromagnetic performance for wireless body area network systems

In this work, the utilization of different textile materials for manufacturing of metamaterial with the aim of controlling the signal propagation in smart textile applications is investigated. The performance of composite structures of embroidered yarn conductor transmission lines loaded with split-ring resonator geometries in felt and cotton substrates are reported. The proposed structure allows propagating or filtering the transmitted signal in the microwave frequency range. The experimental results exhibit a rejection band between 1.3 and 2.6 GHz for felt substrate and between 1.6 and 2.6 GHz for cotton substrate with stop-band levels lower than –20 dB. The presented e-textile structures are designed, electromagnetically simulated and measured. The measured results are in good agreement with three-dimensional electromagnetic simulations. The effect of bending of the e-textiles for realistic scenarios is also studied. The experimental results show that by changing the radius of bending from 10 to 65 mm, the resonance frequency is shifted up 290 and 144 MHz for cotton and felt substrates, respectively.Postprint (author's final draft

Embroidery textile moisture sensor

Postprint (published version

Impact of conductive yarns on an embroidery textile moisture sensor

In this work, two embroidered textile moisture sensors are characterized with three different conductive yarns. The sensors are based on a capacitive interdigitated structure embroidered on a cotton substrate with an embroidered conductor yarn. The performance comparison of three different type of conductive yarns has been addressed. In order to evaluate the sensor sensitivity, the impedance of the sensor has been measured by means of an LCR meter from 20 Hz to 20 kHz on a climatic chamber with a sweep of the relative humidity from 30% to 65% at 20 ¿C. The experimental results show a clear and controllable dependence of the sensor impedance with the relative humidity and the chosen conductor yarns. This dependence points out the optimum conductive yarn to be used to develop wearable applications for moisture measurementPostprint (published version

EBG filtering structure using thick film high dielectric constant resonators

This paper reports the design of a stop-pass and band-pass filtering EBG structure operating in the Ku band by using thick film high dielectric constant resonators. The design is based on a microstrip linethat periodically loaded with a new kind of dielectric resonator fabricated with a commercial high dielectricconstant epoxy paste which compatible with serigraphy and screen printing technology. The geometry of theresonator has been chosen in such a way that, the filtering structure appear below the first resonant frequency.An equivalent circuit model of the proposed structure is discussed and compared with electromagneticsimulations and measurementsPeer ReviewedPostprint (published version

Wearable ring resonator antenna

Postprint (author's final draft

Study of double ring resonator embroidered wearable antennas for microwave applications

In this work, the design, implementation and test of double ring resonator (DRR) wearable antennas is carried out. Specifically, symmetrical and non-symmetrical DRRs are coupled to a transmission line by means embroidered metallic thread on a felt substrate. Both designs present good e-textile antenna parameters performance in terms of return loss, directivity, realized gain and efficiency. Moreover, the specific absorption rate (SAR) to preserve the human body safety from radiation has been analyzed by means of numerical simulations including a realistic human voxel model, according to the international regulation. Experimental results confirm that the embroidered DRR antennas present a useful technique to transmit/receive microwave signals on wearable applications.Peer ReviewedPostprint (published version

A Review on biomedical application of polysaccharide-based hydrogels with a focus on drug delivery systems

Over the last years of research on drug delivery systems (DDSs), natural polymer-based 18 hydrogels have shown many scientific advances due to their intrinsic properties and a wide variety 19 of potential applications. While drug efficacy and cytotoxicity play a key role, adopting a proper 20 DDS is crucial to preserve the drug along the route of administration and possess desired therapeu-21 tic effect at the targeted site. Thus, drug delivery technology can be used to overcome the difficulties 22 of maintaining drugs at a physiologically related serum concentration for prolonged periods. Due 23 to their outstanding biocompatibility, polysaccharides have been thoroughly researched as a bio-24 logical material for DDS advancement. To formulate a modified DDS, polysaccharides can cross-25 link with different molecules, resulting in hydrogels. According to our recent findings, targeted 26 drug delivery at a certain spot occurs due to external stimulation like temperature, pH, glucose, or 27 light. As an adjustable biomedical device, the hydrogel has tremendous potential for nanotech ap-28 plications in the involved health area like pharmaceutical and biomedical engineering. An overview 29 of hydrogel characteristics and functionalities is provided in this review. We focus on discussing 30 the various kinds of hydrogel-based on their potential for effectively delivering drugs that are made 31 of polysaccharides