The Programmable Design of Large-Area Piezoresistive Textile Sensors Using Manufacturing by Jacquard Processing

Abstract

Among wearable e-textiles, conductive textile yarns are of particular interest because they can be used as flexible and wearable sensors without affecting the usual properties and comfort of the textiles. Firstly, this study proposed three types of piezoresistive textile sensors, namely, single-layer, double-layer, and quadruple-layer, to be made by the Jacquard processing method. This method enables the programmable design of the sensor’s structure and customizes the sensor’s sensitivity to work more efficiently in personalized applications. Secondly, the sensor range and coefficient of determination showed that the sensor is reliable and suitable for many applications. The dimensions of the proposed sensors are 20 × 20 cm, and the thicknesses are under 0.52 mm. The entire area of the sensor is a pressure-sensitive spot. Thirdly, the effect of layer density on the performance of the sensors showed that the single-layer pressure sensor has a thinner thickness and faster response time than the multilayer pressure sensor. Moreover, the sensors have a quick response time (<50 ms) and small hysteresis. Finally, the hysteresis will increase according to the number of conductive layers. Many tests were carried out, which can provide an excellent knowledge database in the context of large-area piezoresistive textile sensors using manufacturing by Jacquard processing. The effects of the percolation of CNTs, thickness, and sheet resistance on the performance of sensors were investigated. The structural and surface morphology of coating samples and SWCNTs were evaluated by using a scanning electron microscope. The structure of the proposed sensor is expected to be an essential step toward realizing wearable signal sensing for next-generation personalized applications.

Classification of Breathing Signals According to Human Motions by Combining 1D Convolutional Neural Network and Embroidered Textile Sensor

“…This study analyzed the factors that significantly affect the change in capacitance values using a fiber-type capacitive respiration sensor with embroidered electrodes, connectors, and connector connection lines. The conductive yarn used in the embroidery is made of silver-coated nylon filaments, which offer excellent conductivity, low susceptibility to corrosion, and suitability for embroidery [ 33 , 34 ]. Moreover, it is safe for human use without causing harm [ 16 ].…”

“…This silver-coated conductive yarn was specifically chosen for its excellent conductivity and low susceptibility to corrosion, making it an ideal choice for creating conductive surfaces [ 33 ], especially for applications such as sewing or embroidery [ 34 ]. Furthermore, as confirmed by the cytotoxicity test conducted in accordance with the Biological evaluation of medical devices standard (DIN EN ISO 10993-5), there was no cellular damage observed.…”

Development of Embroidery-Type Sensor Capable of Detecting Respiration Using the Capacitive Method

“…Silver-coated outer nylon cores used in this study are twisted 34 filaments to create a single conductive yarn. We selected this silver-tech conductive yarn because of its high conductivity and low corrosion resistance, which is ideal for conductive surfaces [ 16 ], particularly for sewing or embroidery [ 17 ]. The electrical resistance of each ply of the yarn, as determined using an LCR meter, is depicted in Figure 2 .…”

Novel SMD Component and Module Interconnection and Encapsulation Technique for Textile Substrates Using 3D Printed Polymer Materials

“…E-textiles enable a wide range of applications with respect to health monitoring (e.g., edema [4] or apnea [5] monitoring, hydration [6], and temperature measurement [7]), maintaining a comfortable temperature [8][9][10], measuring mechanical strain [11,12] integrating safety LED lighting [13], and facilitating wireless communication by means of textile antennas [14]. Conductive patterns and sensors on textile substrates can be created by typical textile fabrication technologies, such as weaving [15,16], knitting [17,18], or embroidering (Table 1) using microwires [19,20] or electrically conductive polymer yarns [21][22][23][24], by the deposition of conductive polymer pastes [25], or by a combination of the selective patterning of Ag NPs and electroless Cu-plating [26]. However, conventional semiconductor components or evaluation circuits either in SMD (surface-mounted device) packages or mounted on printed circuit boards (PCB) cannot easily be substituted by conductive or semiconductive yarns and have to be placed and electrically contacted on the textile substrates.…”