Electronic Textile Materials

In this work, we reported the electrochemical performance of a type of carbon fabric-based supercapacitor by coating MnOx@rGO nanohybrids on carbon fabric with a simple one-step hydrothermal method. We studied the mass ratio of MnOx to rGO on the electrochemical properties of the carbon fabric-based supercapacitors. We found that as the mass ratio is 0.8:1 for MnO@rGO, the supercapacitor with a loading of 5.40 mg cm⁻² of MnO@rGO nanohybrids on carbon fabric exhibits a specific capacitance of 831.25 mF cm⁻² at 0.1 mA cm⁻² current density. It also shows long-term cycling capacitance retention of 97.2% after 10,000 charge–discharge cycles at a current density of 0.4 mA cm⁻². We speculate that the high electrochemical performance results from the strong interfacial bonding between the hierarchical architecture of MnO@rGO nanohybrids and carbon fabric. Full article

Antennas dedicated to RFID systems created on textile substrates should maintain strictly defined parameters. During washing, the materials from which such antennas are made are exposed to mechanical and chemical exposure—degradation of the parameters characterizing those materials may occur, which in turn may lead to a change in the parameters of the antenna. For research purposes, four groups of model dipole antennas (sewn with two types of conductive threads on two fabrics) were created and then they were subjected to several washing processes. After each stage of the experiment, the impedance parameters of the demonstration antennas were measured using indirect measurements. Based on the obtained results, it was found that these parameters change their values during washing, and that this is influenced by a number of factors, e.g., shrinkage of the substrate fabric. Full article

Over the past few years, alternative power supplies to either supplement or replace batteries for electronic textile and wearable applications have been sought, with the development of wearable solar energy harvesting systems gaining significant interest. In a previous publication the authors reported a novel concept to craft a yarn capable of harvesting solar energy by embedding miniature solar cells within the fibers of a yarn (solar electronic yarns). The aim of this publication is to report the development of a large-area textile solar panel. This study first characterized the solar electronic yarns, and then analyzed the solar electronic yarns once woven into double cloth woven textiles; as part of this study, the effect of different numbers of covering warp yarns on the performance of the embedded solar cells was explored. Finally, a larger woven textile solar panel (510 mm × 270 mm) was constructed and tested under different light intensities. It was observed that a P_MAX = 335.3 ± 22.4 mW of energy could be harvested on a sunny day (under 99,000 lux lighting conditions). Full article

Falls can be detrimental to the quality of life of older people, and therefore the ability to detect falls is beneficial, especially if the person is living alone and has injured themselves. In addition, detecting near falls (when a person is imbalanced or stumbles) has the potential to prevent a fall from occurring. This work focused on the design and engineering of a wearable electronic textile device to monitor falls and near-falls and used a machine learning algorithm to assist in the interpretation of the data. A key driver behind the study was to create a comfortable device that people would be willing to wear. A pair of over-socks incorporating a single motion sensing electronic yarn each were designed. The over-socks were used in a trial involving 13 participants. The participants performed three types of activities of daily living (ADLs), three types of falls onto a crash mat, and one type of near-fall. The trail data was visually analyzed for patterns, and a machine learning algorithm was used to classify the data. The developed over-socks combined with the use of a bidirectional long short-term memory (Bi-LSTM) network have been shown to be able to differentiate between three different ADLs and three different falls with an accuracy of 85.7%, ADLs and falls with an accuracy of 99.4%, and ADLs, falls, and stumbles (near-falls) with an accuracy of 94.2%. In addition, results showed that the motion sensing E-yarn only needs to be present in one over-sock. Full article

Recent advances in the development of innovative textronic products are often related to the implementation of radio-frequency identification (RFID) technology. Such devices contain components of wireless telecommunications systems, in which radiofrequency circuits should be designed taking into account not only the frequency band or destined application, but also the dielectric properties of the materials. As is known from the theory of RFID systems, the dielectric permittivity and loss angle of the substrates significantly affect the performance of RFID transponders. Therefore, the knowledge on the variability of these parameters is highly important in the context of developing new solutions in textronic devices with the RFID interface. According to the plan of studies, at the beginning, the comprehensive characterization and determination of the dielectric parameters of various types of textile substrates were carried out. On this basis, the influence of fabrics on the performance of textronic RFID (RFIDtex) tags was characterized with numerical calculations. As the RFIDtex transponders proposed by the authors in the patent PL231291 have an outstanding design in which the antenna and the chip are located on physically separated substrates and are galvanically isolated, the special means had to be implemented when creating a numerical model. On the other hand, the great advantage of the developed construction was confirmed. Since the impedance at the chip’s terminals is primarily determined by the coupling system, the selected fabrics have relatively low impact on the efficiency of the RFIDtex transponder. Such an effect is impossible to achieve with classical designs of passive or semi-passive transponders. The correctness of the simulations was verified on the exemplary demonstrators, in threshold and rotation measurements performed at the laboratory stand. Full article