A Full Textile Capacitive Woven Sensor

Abstract

In this paper, a full textile capacitive woven sensor integrated over a textile substrate is presented. The sensor consists in an interdigitated capacitance prepared to measure moisture and/or presence detection. In order to evaluate the sensor response to moisture, capacitance has been measured by means of an LCR meter from 20 Hz to 20 kHz in a climatic chamber with a swept of the relative humidity (RH) from 30% to 90% at 20 °C. Subsequently, presence response is evaluated measuring the capacitance of the woven sensor meanwhile a person is sitting down and getting up. The woven sensor results demonstrate its functionality over moisture measurement where sensor capacitance changes from a minimum of 9.74 pF at 30% RH to a maximum of 2.31 uF at 90% RH. The presence detection is also demonstrated, which makes the capacitance variation change from a 10% of capacitance variation when the chair is empty, to a capacitance variation of 170% when a person is sitting on it. The adaptation of the weaving process to accomplish a fully integrated sensor provides a better repeatability than previous embroidered sensors and opens a door to being commercially produced.

Braiding, twisting, and weaving microscale fibers with capillary forces

“…We envision that such machines could be used to make Litz wire or woven micro-textiles for applications such as soft actuation 35 and smart textile wearables. 36 Other future work might focus on the development of machines that can make topologies like knots, pseudoknots, and weaves that consist of multiple layers.…”

Driver Position Measured Based on Textile Capacitive Sensor Array

“…However, these sensors are not fully integrated in textile seats. In this sense, the authors demonstrated the functionality of a fully integrated woven capacitive sensor for seat occupancy detection [5]. Based on this previous work, in this paper a textile sensor array is integrated on the base and backrest of a car seat to measure the driver's posture, providing useful information to prevent traffic accidents.…”

Highly Stretchable Textile Knitted Interdigital Sensor for Wearable Technology Applications

“…Establishing soft reliable electrodes is of utmost significance to ensure long-term functionality and durability. [40][41][42][43][44][45][46][47][48][49][50][51][52] Interdigital capacitive sensors have been integrated using various textile production methods, such as weaving [53] and embroidery [54,55] technologies. These interdigital sensor production approaches, however, do not impose stretchability constraints and completely support the different body proportions and movement requirements of wearable technologies.…”