Functional Fabrics for Multilayered Textile Pressure Sensors: Comparison of Structures and Sensitivity Characteristics
22nd International Scientific Conference "Engineering for Rural Development": Proceedings. Vol.22 2023
Aleksandrs Vališevskis, Uģis Briedis, Aleksandrs Okss, Ilze Baltiņa

In the field of protective smart clothing, such topics as monitoring of wearer’s vital signs and spatial position are thoroughly studied in the literature. On the other hand, solutions for monitoring of hazardous events, such as high-energy impacts with foreign objects are studied to less extent. Such protective clothing is intended both for operators, working in environments with a risk of injury due to impact with moving parts or falling objects, e.g. operators of heavy agricultural machinery, first responders etc. Such a sensor would enable to detect the location of the impact, its force and would allow to develop a system that sends appropriate emergency signals. The proposed paper focuses on the development of such a sensor, giving a special attention to its structure and usable materials. The proposed matrix array sensor consists of three layers: upper and lower layers with electrically conductive traces and the intermediate piezoresistive layer. Due to the intended application, a textile piezoresistive layer is chosen and after studying the commercially available materials, EeonTex LTT-SLPA 60 kOhm conductive polymer-coated knitted fabric and Sefar Carbotex 03-120CF, 03-160CF and 03-205CF carbon/polyester woven fabrics were selected as the most suitable candidates for further testing. The testing was accomplished using Zwick/Roell Z2.5 compression/strain testing column and Agilent A34970A ohmmeter. The testing focused on changes in fabrics’ conductivity under cyclic stress, sensitivity, measurement hysteresis and repeatability. Different technologies for connecting the piezoresistive and the outside layers were tested as well: direct connection and connection using conductive adhesive textile tapes. Based on the results obtained during testing, recommendations are given for the usage of the studied materials, based on their performance under various levels of stress. During the experiments the best metrological results were demonstrated by piezoresistive fabrics with conductive polymer coating. Besides that, it was concluded that while hot-melt adhesive conductive tapes substantially degrade the sensors’ properties, the use of self-adhesive conductive tapes ensure constant and stable contact between the sandwich layers and thus improve the measuring stability.


Keywords
smart textiles, sensors, protective garment
DOI
10.22616/ERDev.2023.22.TF089
Hyperlink
https://www.tf.lbtu.lv/conference/proceedings2023/Papers/TF089.pdf

Vališevskis, A., Briedis, U., Okss, A., Baltiņa, I. Functional Fabrics for Multilayered Textile Pressure Sensors: Comparison of Structures and Sensitivity Characteristics. In: 22nd International Scientific Conference "Engineering for Rural Development": Proceedings. Vol.22, Latvia, Jelgava, 24-26 May, 2023. Jelgava: LLU, 2023, pp.419-426. ISSN 1691-5976. Available from: doi:10.22616/ERDev.2023.22.TF089

Publication language
English (en)
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