{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,19]],"date-time":"2026-06-19T16:38:44Z","timestamp":1781887124801,"version":"3.54.5"},"reference-count":30,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2022,8,30]],"date-time":"2022-08-30T00:00:00Z","timestamp":1661817600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Industrielle Gemeinschaftsforschung"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>One of the main challenges during the integration of a carbon\/polymer-based nanocomposite sensor on textile substrates is the fabrication of a homogeneous surface of the nanocomposite-based thin films, which play a major role in the reproducibility of the sensor. Characterizations are therefore required in every fabrication step to control the quality of the material preparation, deposition, and curing. As a result, microcharacterization methods are more suitable for laboratory investigations, and electrical methods can be easily implemented for in situ characterization within the manufacturing process. In this paper, several textile-based pressure sensors are fabricated at an optimized concentration of 0.3 wt.% of multiwalledcarbon nanotubes (MWCNTs) composite material in PDMS. We propose to use impedance spectroscopy for the characterization of both of the resistive behavior and capacitive behavior of the sensor at several frequencies and under different loads from 50 g to 500 g. The impedance spectra are fitted to a model composed of a resistance in series with a parallel combination of resistance and a constant phase element (CPE). The results show that the printing parameters strongly influence the impedance behavior under different loads. The deviation of the model parameter \u03b1 of the CPE from the value 1 is strongly dependent on the nonhomogeneity of the sensor. Based on an impedance spectrum measurement followed by parameter extraction, the parameter \u03b1 can be determined to realize a novel method for homogeneity characterization and in-line quality control of textile-integrated wearable sensors during the manufacturing process.<\/jats:p>","DOI":"10.3390\/s22176530","type":"journal-article","created":{"date-parts":[[2022,8,31]],"date-time":"2022-08-31T00:13:56Z","timestamp":1661904836000},"page":"6530","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Homogeneity Characterization of Textile-Integrated Wearable Sensors based on Impedance Spectroscopy"],"prefix":"10.3390","volume":"22","author":[{"given":"Hanen","family":"Nouri","sequence":"first","affiliation":[{"name":"Measurement and Sensor Technology, Chemnitz University of Technology, 09126 Chemnitz, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3554-5751","authenticated-orcid":false,"given":"Dhivakar","family":"Rajendran","sequence":"additional","affiliation":[{"name":"Measurement and Sensor Technology, Chemnitz University of Technology, 09126 Chemnitz, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rajarajan","family":"Ramalingame","sequence":"additional","affiliation":[{"name":"Measurement and Sensor Technology, Chemnitz University of Technology, 09126 Chemnitz, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7166-1266","authenticated-orcid":false,"given":"Olfa","family":"Kanoun","sequence":"additional","affiliation":[{"name":"Measurement and Sensor Technology, Chemnitz University of Technology, 09126 Chemnitz, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,8,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"130599","DOI":"10.1016\/j.cej.2021.130599","article-title":"A dual-mode electronic skin textile for pressure and temperature sensing","volume":"425","author":"Wang","year":"2021","journal-title":"Chem. Eng. J."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"523","DOI":"10.1021\/acs.accounts.8b00500","article-title":"Flexible electronics toward wearable sensing","volume":"52","author":"Gao","year":"2019","journal-title":"Acc. Chem. Res."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1801072","DOI":"10.1002\/adma.201801072","article-title":"Advanced carbon for flexible and wearable electronics","volume":"31","author":"Wang","year":"2019","journal-title":"Adv. Mater."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"109886","DOI":"10.1016\/j.matdes.2021.109886","article-title":"Pressure and temperature sensitive e-skin for in situ robotic applications","volume":"208","author":"Dinh","year":"2021","journal-title":"Mater. Des."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"4825","DOI":"10.1002\/adma.201401364","article-title":"Reverse-micelle-induced porous pressure-sensitive rubber for wearable human\u2013machine interfaces","volume":"26","author":"Jung","year":"2014","journal-title":"Adv. Mater."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"4338","DOI":"10.1002\/adma.201504244","article-title":"Flexible and stretchable physical sensor integrated platforms for wearable human-activity monitoringand personal healthcare","volume":"28","author":"Trung","year":"2016","journal-title":"Adv. Mater."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1602790","DOI":"10.1002\/smll.201602790","article-title":"Flexible sensing electronics for wearable\/attachable health monitoring","volume":"13","author":"Wang","year":"2017","journal-title":"Small"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1016\/j.snb.2018.08.155","article-title":"Towards conductive-gel-free electrodes: Understanding the wet electrode, semi-dry electrode and dry electrode-skin interface impedance using electrochemical impedance spectroscopy fitting","volume":"277","author":"Li","year":"2018","journal-title":"Sens. Actuat. B Chem."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"046016","DOI":"10.1088\/1741-2552\/abeeab","article-title":"Towards real-life EEG applications: Novel superporous hydrogel-based semi-dry EEG electrodes enabling automatically \u2018charge\u2013discharge\u2019electrolyte","volume":"18","author":"Li","year":"2021","journal-title":"J. Neural Eng."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"Grishanov, S. (2011). Structure and properties of textile materials. Handbook of Textile and Industrial Dyeing, Elsevier.","DOI":"10.1533\/9780857093974.1.28"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"321","DOI":"10.1016\/0250-6874(86)80053-1","article-title":"Thermal sensors based on the Seebeck effect","volume":"10","author":"Sarro","year":"1986","journal-title":"Sens. Actuat."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"108451","DOI":"10.1016\/j.matdes.2019.108451","article-title":"Investigation into tensile hysteresis of polyurethane-containing textile substrates for coated strain sensors","volume":"188","author":"Li","year":"2020","journal-title":"Mater. Des."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"3895","DOI":"10.3390\/s21113895","article-title":"Carbonized Cotton Fabric-Based Flexible Capacitive Pressure Sensor Using a Porous Dielectric Layer with Tilted Air Gaps","volume":"21","author":"Ko","year":"2021","journal-title":"Sensors"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"130682","DOI":"10.1016\/j.cej.2021.130682","article-title":"Coating of multi-wall carbon nanotubes (MWCNTs) on three-dimensional, bicomponent nonwovens as wearable and high-performance piezoresistive sensors","volume":"425","author":"Tian","year":"2021","journal-title":"Chem. Eng. J."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1076","DOI":"10.3390\/nano9081076","article-title":"Flexible HIV-1 biosensor based on the Au\/MoS2 nanoparticles\/Au nanolayer on the PET substrate","volume":"9","author":"Shin","year":"2019","journal-title":"Nanomaterials"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"16215","DOI":"10.1007\/s10854-021-06170-4","article-title":"PDMS\/MWCNT nanocomposites as capacitive pressure sensor and electromagnetic interference shielding materials","volume":"32","author":"Panda","year":"2021","journal-title":"J. Mater. Sci. Mater. Electron."},{"key":"ref_17","first-page":"943406","article-title":"Flexible pressure sensors for burnt skin patient monitoring","volume":"Volume 9434","author":"Hong","year":"2015","journal-title":"Nanosensors, Biosensors, and Info-Tech Sensors and Systems"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"7774","DOI":"10.1109\/JSEN.2020.2981262","article-title":"Optimization of reduced GO-based cotton electrodes for wearable electrocardiography","volume":"20","author":"Saleh","year":"2020","journal-title":"IEEE Sens. J."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"045105","DOI":"10.1088\/0957-0233\/27\/4\/045105","article-title":"Capacitive wearable tactile sensor based on smart textile substrate with carbon black\/silicone rubber composite dielectric","volume":"27","author":"Guo","year":"2016","journal-title":"Meas. Sci. Technol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1063\/1.5089900","article-title":"Piezo-impedance response of carbon nanotube\/polydimethylsiloxane nanocomposites","volume":"7","author":"Jeon","year":"2019","journal-title":"APL Mater."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.compscitech.2015.11.012","article-title":"Piezoresistive characterization of multi-walled carbon nanotube-epoxy based flexible strain sensitive films by impedance spectroscopy","volume":"122","author":"Sanli","year":"2016","journal-title":"Compos. Sci. Technol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"845","DOI":"10.1177\/0021998319870592","article-title":"Electrical impedance analysis of carbon nanotube\/epoxy nanocomposite-based piezoresistive strain sensors under uniaxial cyclic static tensile loading","volume":"54","author":"Sanli","year":"2020","journal-title":"J. Compos. Mater."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.cemconcomp.2019.03.018","article-title":"A review on microstructural characterization of cement-based materials by AC impedance spectroscopy","volume":"100","author":"Hu","year":"2019","journal-title":"Cem. Concr. Compos."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1454","DOI":"10.1590\/1980-5373-mr-2016-0825","article-title":"Polydimethylsiloxane membranes containing multi-walled carbon nanotubes for gas separation","volume":"20","author":"Silva","year":"2017","journal-title":"Mater. Res."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"87","DOI":"10.5194\/jsss-8-87-2019","article-title":"Highly sensitive capacitive pressure sensors for robotic applications based on carbon nanotubes and PDMS polymer nanocomposite","volume":"8","author":"Ramalingame","year":"2019","journal-title":"J. Sens. Sens. Syst."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Xu, F., Li, X., Shi, Y., Li, L., Wang, W., He, L., and Liu, R. (2018). Recent developments for flexible pressure sensors: A review. Micromachines, 9.","DOI":"10.3390\/mi9110580"},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Kanoun, O., Bouhamed, A., Ramalingame, R., Bautista-Quijano, J.R., Rajendran, D., and Al-Hamry, A. (2021). Review on conductive polymer\/CNTs nanocomposites based flexible and stretchable strain and pressure sensors. Sensors, 21.","DOI":"10.3390\/s21020341"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1","DOI":"10.5194\/jsss-8-1-2019","article-title":"Flexible piezoresistive sensor matrix based on a carbon nanotube PDMS composite for dynamic pressure distribution measurement","volume":"8","author":"Ramalingame","year":"2019","journal-title":"J. Sens. Sens. Syst."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Farag\u00f3, P., Cirlugea, M., and Hintea, S. (2020, January 7\u20139). A novel smart-shoe architecture for podiatric monitoring. Proceedings of the 2020 43rd International Conference on Telecommunications and Signal Processing (TSP), Milan, Italy.","DOI":"10.1109\/TSP49548.2020.9163549"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1038\/s41528-019-0057-1","article-title":"Screen printing of silver nanowires: Balancing conductivity with transparency while maintaining flexibility and stretchability","volume":"3","author":"Li","year":"2019","journal-title":"npj Flex. Electron."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/17\/6530\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T00:20:04Z","timestamp":1760142004000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/17\/6530"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,8,30]]},"references-count":30,"journal-issue":{"issue":"17","published-online":{"date-parts":[[2022,9]]}},"alternative-id":["s22176530"],"URL":"https:\/\/doi.org\/10.3390\/s22176530","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,8,30]]}}}