A wearable and stretchable strain sensor with a gauge factor above 23 was prepared using a simple and effective technique. Conducting nanocomposite strands were prepared from styrene-b-(ethylene-co-butylene)-b-styrene triblock copolymer (SEBS) and carbon black (CB) through a solvent-processing method that uses a syringe pump. This novel nanocomposite preparation technique is a straightforward and cost-effective process and is reported in the literature for the first time. The work included two stages: the flexible nanocomposite preparation stage and the piezoresistive sensor stage. Depending on its molecular structure, the thermoelastic polymer SEBS is highly resilient to stress and strain. The main aim of this work is to fabricate a highly flexible and piezoresistive nanocomposite fibre/strand. Among the prepared composites, a composite corresponding to a composition just above the percolation threshold was selected to prepare the strain sensor, which exhibited good flexibility and conductivity and a large piezoresistive effect that was linearly dependent on the applied strain. The prepared nanocomposite sensor was stitched onto a sports T-shirt. Commercially available knee and elbow sleeves were also purchased, and the nanocomposite SEBS/CB strands were sewn separately on the two sleeves. The results showed a high sensitivity of the sensing element in the case of breathing activity (normal breathing, a 35% change, and deep breathing at 135%, respectively). In the case of knee and elbow movements, simultaneous measurements were performed and found that the sensor was able to detect movement cycles during walking.

Centre of Polymer Systems Tomas Bata University in Zlín Tr Tomase Bati 5678 760 01 Zlin Czech Republic

Department of Chemistry Faculty of Technology Tomas Bata University in Zlín Vavrečkova 5669 760 01 Zlin Czech Republic

Department of Physics and Materials Engineering Faculty of Technology Tomas Bata University in Zlín Vavrečkova 5669 760 01 Zlin Czech Republic

Zobrazit více v PubMed

Nguyen T., Dinh T., Phan H.P., Pham T.A., Dau V.T., Nguyen N.T., Dao D.V. Advances in ultrasensitive piezoresistive sensors: From conventional to flexible and stretchable applications. Mater. Horiz. 2021;8:2123–2150. doi: 10.1039/D1MH00538C. PubMed DOI

Fiorillo A.S., Critello C.D., Pullano A.S. Theory, technology and applications of piezoresistive sensors: A review. Sens. Actuators A Phys. 2018;281:156–175. doi: 10.1016/j.sna.2018.07.006. DOI

Fraden J. Handbook of Modern Sensors: Physics, Designs, and Applications. 5th ed. Springer; Berlin/Heidelberg, Germany: 2016. DOI

Liu X., Miao J., Fan Q., Zhang W., Zuo X., Tian M., Zhu S., Zhang X., Qu L. Recent Progress on Smart Fiber and Textile Based Wearable Strain Sensors: Materials, Fabrications and Applications. Adv. Fiber Mater. 2022;4:361–389. doi: 10.1007/s42765-021-00126-3. DOI

Leal-Junior A., Avellar L., Frizera A., Marques C. Smart textiles for multimodal wearable sensing using highly stretchable multiplexed optical fiber system. Sci. Rep. 2020;10:13867. doi: 10.1038/s41598-020-70880-8. PubMed DOI PMC

Lin S., Hu S., Song W., Gu M., Liu J., Song J., Liu Z., Li Z., Huang K., Wu Y., et al. An ultralight, flexible, and biocompatible all-fiber motion sensor for artificial intelligence wearable electronics. Npj Flex. Electron. 2022;6:27. doi: 10.1038/s41528-022-00158-8. DOI

Zeng W., Shu L., Li Q., Chen S., Wang F., Tao X.M. Fiber-based wearable electronics: A review of materials, fabrication, devices, and applications. Adv. Mater. 2014;26:5310–5336. doi: 10.1002/adma.201400633. PubMed DOI

Jin H., Abu-Raya Y.S., Haick H. Advanced Materials for Health Monitoring with Skin-Based Wearable Devices. Adv. Healthc. Mater. 2017;6:1700024. doi: 10.1002/adhm.201700024. PubMed DOI

Gao L., Zhu C., Li L., Zhang C., Liu J., Yu H.D., Huang W. All Paper-Based Flexible and Wearable Piezoresistive Pressure Sensor. ACS Appl. Mater. Interfaces. 2019;11:25034–25042. doi: 10.1021/acsami.9b07465. PubMed DOI

Zheng Q., Lee J., Shen X., Chen X., Kim J.-K. Graphene-based wearable piezoresistive physical sensors. Mater. Today. 2020;36:158–179. doi: 10.1016/j.mattod.2019.12.004. DOI

Dios J.R., Gonzalo B., Tubio C.R., Cardoso J., Gonçalves S., Miranda D., Correia V., Viana J.C., Costa P., Lanceros-Méndez S. Functional Piezoresistive Polymer-Composites Based on Polycarbonate and Polylactic Acid for Deformation Sensing Applications. Macromol. Mater. Eng. 2020;305:2000379. doi: 10.1002/mame.202000379. DOI

Nath K., Khanal S., Krause B., Lach R. Electrically conductive and piezoresistive polymer nanocomposites using multiwalled carbon nanotubes in a flexible copolyester: Spectroscopic, morphological, mechanical and electrical properties. Nano-Struct. Nano-Objects. 2022;29:100806. doi: 10.1016/j.nanoso.2021.100806. DOI

Shen Z., Feng J. Mass-produced SEBS/graphite nanoplatelet composites with a segregated structure for highly stretchable and recyclable strain sensors. J. Mater. Chem. C. 2019;7:9423–9429. doi: 10.1039/C9TC02321F. DOI

Cetin M.S., Karahan Toprakci H.A. Flexible electronics from hybrid nanocomposites and their application as piezoresistive strain sensors. Compos. Part B Eng. 2021;224:109199. doi: 10.1016/j.compositesb.2021.109199. DOI

Costa P., Oliveira J., Horta-Romarís L., Abad M.J., Moreira J.A., Zapiráin I., Aguado M., Galván S., Lanceros-Mendez S. Piezoresistive polymer blends for electromechanical sensor applications. Compos. Sci. Technol. 2018;168:353–362. doi: 10.1016/j.compscitech.2018.10.022. DOI

Padovano E., Bonelli M.E., Veca A., De Meo E., Badini C. Effect of long-term mechanical cycling and laser surface treatment on piezoresistive properties of SEBS-CNTs composites. React. Funct. Polym. 2020;152:104601. doi: 10.1016/j.reactfunctpolym.2020.104601. DOI

Ma L., Lei X., Li S., Guo S., Yuan J., Li X., Cheng G.J., Liu F. A 3D flexible piezoresistive sensor based on surface-filled graphene nanosheets conductive layer. Sens. Actuators A Phys. 2021;332:113144. doi: 10.1016/j.sna.2021.113144. DOI

Njuguna M.K., Yan C., Hu N., Bell J.M., Yarlagadda P.K.D.V. Sandwiched carbon nanotube film as strain sensor. Compos. Part B Eng. 2012;43:2711–2717. doi: 10.1016/j.compositesb.2012.04.022. DOI

Akhtar I., Chang S.H. Radial alignment of carbon nanotubes for directional sensing application. Compos. Part B Eng. 2021;222:109038. doi: 10.1016/j.compositesb.2021.109038. DOI

Akhtar I., Chang S.H. Highly aligned carbon nanotubes and their sensor applications. Nanoscale. 2020;12:21447–21458. doi: 10.1039/D0NR05951J. PubMed DOI

Zeng J., Ma W., Wang Q., Yu S., Innocent M.T., Xiang H., Zhu M. Strong, high stretchable and ultrasensitive SEBS/CNTs hybrid fiber for high-performance strain sensor. Compos. Commun. 2021;25:100735. doi: 10.1016/j.coco.2021.100735. DOI

Sam-daliri O., Faller L., Farahani M., Roshanghias A. MWCNT–Epoxy Nanocomposite Sensors for Structural Health Monitoring. Electronics. 2018;7:143. doi: 10.3390/electronics7080143. DOI

Enrique-Jimenez P., Quiles-Díaz S., Salavagione H.J., Wesner D., Schönherr H., González-Casablanca J., García-Quismondo R., Martínez G., Gómez-Fatou M., Ania F., et al. Control of the structure and properties of SEBS nanocomposites via chemical modification of graphene with polymer brushes. Eur. Polym. J. 2017;97:1–13. doi: 10.1016/j.eurpolymj.2017.09.047. DOI

Costa P., Gonçalves S., Mora H., Carabineiro S.A.C., Viana J.C., Lanceros-Mendez S. Highly Sensitive Piezoresistive Graphene-Based Stretchable Composites for Sensing Applications. ACS Appl. Mater. Interfaces. 2019;11:46286–46295. doi: 10.1021/acsami.9b19294. PubMed DOI

Pan S., Pei Z., Jing Z., Song J., Zhang W., Zhang Q., Sang S. A highly stretchable strain sensor based on CNT/graphene/fullerene-SEBS. RSC Adv. 2020;10:11225–11232. doi: 10.1039/D0RA00327A. PubMed DOI PMC

Ghabezi P., Farahani M. In: Effects of Nanoparticles on Nanocomposites Mode I and II Fracture: A Critical Review. Mittal K.L., editor. Volume 4. Scrivener Publishing LLC; Beverly, MA, USA: 2018. pp. 391–411. DOI

Hofmann D., Thomann R., Mülhaupt R. Thermoplastic SEBS Elastomer Nanocomposites Reinforced with Functionalized Graphene Dispersions. Macromol. Mater. Eng. 2018;303:1700324. doi: 10.1002/mame.201700324. DOI

Turgut A., Tuhin M.O., Toprakci O., Pasquinelli M.A., Spontak R.J., Toprakci H.A.K. Thermoplastic Elastomer Systems Containing Carbon Nanofibers as Soft Piezoresistive Sensors. ACS Omega. 2018;3:12648–12657. doi: 10.1021/acsomega.8b01740. PubMed DOI PMC

Moreno I.A.E., Diaz A.D., Duarte M.E.M., Gómez R.I. Strain effect on the electrical conductivity of CB/SEBS and GP/SEBS composites. Macromol. Symp. 2009;283–284:361–368. doi: 10.1002/masy.200950943. DOI

Yang X., Sun L., Zhang C., Huang B., Chu Y., Zhan B. Modulating the sensing behaviors of poly(styrene-ethylene-butylene-styrene)/carbon nanotubes with low-dimensional fillers for large deformation sensors. Compos. Part B Eng. 2019;160:605–614. doi: 10.1016/j.compositesb.2018.12.119. DOI

Kuester S., Merlini C., Barra G.M.O., Ferreira J.C., Lucas A., De Souza A.C., Soares B.G. Processing and characterization of conductive composites based on poly(styrene-b-ethylene-ran-butylene-b-styrene) (SEBS) and carbon additives: A comparative study of expanded graphite and carbon black. Compos. Part B Eng. 2016;84:236–247. doi: 10.1016/j.compositesb.2015.09.001. DOI

Commission EU Commission recommendation of 18 October 2011 on the definition of nanomaterial (2011/696/EU) Off. J. Eur. Communities Legis. 2011;275:38.

Jeong Y., Park J., Lee J., Kim K., Park I. Ultrathin, Biocompatible, and Flexible Pressure Sensor with a Wide Pressure Range and Its Biomedical Application. ACS Sens. 2020;5:481–489. doi: 10.1021/acssensors.9b02260. PubMed DOI

Aziz S., Chang S.H. Smart-fabric sensor composed of single-walled carbon nanotubes containing binary polymer composites for health monitoring. Compos. Sci. Technol. 2018;163:1–9. doi: 10.1016/j.compscitech.2018.05.012. DOI

Yang T., Deng W., Chu X., Wang X., Hu Y., Fan X., Song J., Gao Y., Zhang B., Tian G., et al. Hierarchically Microstructure-Bioinspired Flexible Piezoresistive Bioelectronics. ACS Nano. 2021;15:11555–11563. doi: 10.1021/acsnano.1c01606. PubMed DOI

Salavagione H.J., Shuttleworth P.S., Fernández-Blázquez J.P., Ellis G.J., Gómez-Fatou M.A. Scalable graphene-based nanocomposite coatings for flexible and washable conductive textiles. Carbon. 2020;167:495–503. doi: 10.1016/j.carbon.2020.05.108. DOI

Chen T., Wu G., Panahi-Sarmad M., Wu Y., Xu R., Cao S., Xiao X. A novel flexible piezoresistive sensor using superelastic fabric coated with highly durable SEBS/TPU/CB/CNF nanocomposite for detection of human motions. Compos. Sci. Technol. 2022;227:109563. doi: 10.1016/j.compscitech.2022.109563. DOI

Qin Z., Chen X., Lv Y., Zhao B., Fang X., Pan K. Wearable and high-performance piezoresistive sensor based on nanofiber/sodium algianate synergistically enhanced MXene composite aerogel. Chem. Eng. J. 2023;451:138586. doi: 10.1016/j.cej.2022.138586. DOI

Olivieri F., Rollo G., De Falco F., Avolio R., Bonadies I., Castaldo R., Cocca M., Errico M.E., Lavorgna M., Gentile G. Reduced graphene oxide/polyurethane coatings for wash-durable wearable piezoresistive sensors. Cellulose. 2023;30:2667–2686. doi: 10.1007/s10570-023-05042-w. DOI

Parger M., Tang C., Xu Y., Twigg C.D., Tao L., Li Y., Wang R., Steinberger M. UNOC: Understanding Occlusion for Embodied Presence in Virtual Reality. IEEE Trans. Vis. Comput. Graph. 2021;2626:4240–4251. doi: 10.1109/TVCG.2021.3085407. PubMed DOI

Jiang F., Yang X., Feng L. Real-time full-body motion reconstruction and recognition for off-the-shelf VR devices; Proceedings of the VRCAI 2016 15th ACM SIGGRAPH Conference on Virtual-Reality Continuum and Its Applications in Industry; Zhuhai, China. 3–4 December 2016; pp. 309–318. DOI

Caserman P., Garcia-Agundez A., Gobel S. A Survey of Full-Body Motion Reconstruction in Immersive Virtual Reality Applications. IEEE Trans. Vis. Comput. Graph. 2020;26:3089–3108. doi: 10.1109/TVCG.2019.2912607. PubMed DOI

Matheve T., Brumagne S., Demoulin C., Timmermans A. Sensor-based postural feedback is more effective than conventional feedback to improve lumbopelvic movement control in patients with chronic low back pain: A randomised controlled trial. J. Neuroeng. Rehabil. 2018;15:85. doi: 10.1186/s12984-018-0423-6. PubMed DOI PMC

Nicolò A., Massaroni C., Passfield L. Respiratory frequency during exercise: The neglected physiological measure. Front. Physiol. 2017;8:922. doi: 10.3389/fphys.2017.00922. PubMed DOI PMC

Klüppel M. The Role of Disorder in Filler Reinforcement of Elastomers on Various Length Scales. Adv. Polym. Sci. 2003;164:1–86. doi: 10.1007/b11054. DOI

Beckwith T.G., Buck N.L., Marangoni R.D. Mechanical Measurements. Addison-Wesley Pub. Co.; Reading, MA, USA: 1982.

Pallas-Areny R., Webster J.G. Sensors and Signal Conditioning. John Wiley & Sons; New York, NY, USA: 2012.