Respiration monitoring is a very important indicator of health status. It can be used as a marker in the recognition of a variety of diseases, such as sleep apnea, asthma or cardiac arrest. The purpose of the present study is to overcome limitations of the current state of the art in the field of respiration monitoring systems. Our goal was the development of a lightweight handheld device with portable operation and low power consumption. The proposed approach includes a textile capacitive sensor with interdigitated electrodes embroidered into the facemask, integrated with readout electronics. Readout electronics is based on the direct interface of the capacitive sensor and a microcontroller through just one analog and one digital pin. The microcontroller board and sensor are powered by a smartphone or PC through a USB cable. The developed mobile application for the Android™ operating system offers reliable data acquisition and acts as a bridge for data transfer to the remote server. The embroidered sensor was initially tested in a humidity-controlled chamber connected to a commercial impedance analyzer. Finally, in situ testing with 10 volunteering subjects confirmed stable operation with reliable respiration monitoring.

The COVID-19 pandemic has created a situation where wearing personal protective masks is a must for every human being and introduced them as a part of everyday life. This work demonstrates a new functionality embedded in single-use face masks through an embroidered humidity sensor. The design of the face mask humidity sensor is comprised of interdigitated electrodes made of polyamide-based conductive threads and common polyester threads which act as a dielectric sensing layer embroidered between them. Therefore, the embroidered sensor acts as a capacitor, the performance of which was studied in increasing humidity conditions in the frequency range from 1 Hz to 100 kHz. The moisture adsorbed by sensitive hygroscopic polyester threads altered their dielectric and permittivity properties which were detected by the change in capacitance values of the face mask sensors at different relative humidity (RH) levels. The calculated limit of detection (LOD) values for the two proposed sensors at different frequencies (1, 10, and 100 kHz) were found in the range from 11.46% RH-27.41% RH and 29.79% RH-38.65% RH. The tested sensors showed good repeatability and stability under different humidity conditions over a period of 80 min. By employing direct embroidery of silver-coated polyamide conductive threads and moisture-sensitive polyester threads onto the face mask, the present work exploits the application of polymer-based textile materials in developing novel stretchable sensing devices toward e-textile applications.

A novel paper card-like acting like a credit card to be inserted into a reusable polyvinyl chloride electrochemical fluidic system for furnishing all the reagents required for glucose measurement in artificial tears.

The field of wearable computing technology describes the future of electronic systems being an integral part of our everyday clothing with various enhanced functionalities. The present work is aimed at making closer steps towards the real wearability of electronics using textiles. We designed a fully-textile meander line Zshaped monopole antenna for radio-frequency (RF) harvesting and for short-range communication purposes in the body-area network for various wearable applications. The target antenna was designed in the Ansys HFSS software tool and fabricated on a single-layer cotton textile using silver conductive threads and an embroidery technique. The antenna was characterized using a vector network analyzer (VNA), and the selected design was found to be nearly invariant under different deployment conditions. Antenna performance was studied by measuring the return loss while the antenna was in close proximity to the human body, or under various bending scenarios and/or wet conditions with sweat. The simulated return loss was 20.36dB at an operating frequency of 1.62GHz, and the measured return loss for the fabricated antenna was 19.45dB at 1.6275GHz with a 10dB bandwidth of 100MHz (i.e., 1.58GHz to 1.68GHz), and a fractional bandwidth of 6.17. The results of this study are very important for the design of future wearable antennas in the new concept of the Internet of bodies.