PSI - Issue 80

Marilyne Philibert et al. / Procedia Structural Integrity 80 (2026) 65–76 Author name / Structural Integrity Procedia 00 (2019) 000–000

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4. Conclusions Printed strain gauges offer a promising alternative to traditional sensors for SHM, with advantages in flexibility, scalability, and integration. In comparison with commercially available strain gauges, printed strain gauges in this study demonstrated similar strain responses and sensitivity and good fatigue behaviour. While challenges remain in consistency across prints and bonding quality, ongoing optimization of materials and printing parameters is expected to enhance performance and reliability. Printed piezoresistive strain gauges made from carbon-based inks should also be explored for improved sensitivity and reduced size. Furthermore, co-curing protocol could be developed for proving embedding potential of strain gauges directly printed onto thermoplastic films. The rosette pattern can be easily implemented thanks to the printing technology allowing designing tailored patterns. Besides printing strain gauges, printing piezoelectric sensors for acoustic emission testing may also be explored in the future. Acknowledgements The authors acknowledge funding from the AVATAR project through the European Climate, Infrastructure and Environment Executive Agency (CINEA) under Grant Agreement No. 101096073, and from United Kingdom Research and Innovation (UKRI) under the UK Government's Horizon Europe Guarantee scheme through Grant Agreement No. 10065739. References Bekas, D., Sharif Khodaei, Z., Aliabadi, M.H., 2019. A smart multi-functional printed sensor for monitoring curing and damage of composite repair patch. Smart Materials and Structures. https://doi.org/10.1088/1361-665X/ab2d08 Bekas, D.G., Sharif-Khodaei, Z., Baltzis, D., Aliabadi, M.H.F., Paipetis, A.S., 2019. Quality assessment and damage detection in nanomodified adhesively-bonded composite joints using inkjet-printed interdigital sensors. Composite Structures 211, 557–563. https://doi.org/10.1016/j.compstruct.2019.01.008 Dumstorff, G., Lang, W., 2017. Printed Sensors for Material Integrated Sensing: Functionalization of Semi-Finished Parts. Proceedings 1, 608. https://doi.org/10.3390/proceedings1040608 Gao, K., Zhang, Z., Weng, S., Zhu, H., Yu, H., Peng, T., 2022. Review of Flexible Piezoresistive Strain Sensors in Civil Structural Health Monitoring. Applied Sciences 12, 9750. https://doi.org/10.3390/app12199750 Giurgiutiu, V., 2016. Chapter 8 - Other Sensors for SHM of Aerospace Composites, in: Giurgiutiu, V. (Ed.), Structural Health Monitoring of Aerospace Composites. Academic Press, Oxford, pp. 297–315. https://doi.org/10.1016/B978-0-12-409605-9.00008-8 Glisic, B., 2022. Concise Historic Overview of Strain Sensors Used in the Monitoring of Civil Structures: The First One Hundred Years. Sensors 22, 2397. https://doi.org/10.3390/s22062397 Hassan, M.F., Li, Z., Islam, M.S., Gencturk, B., Zheng, B., Pan, X., Khan, Y., Muin, S., 2025. Wireless Printed Large-Area Sensors for Continuous Structural Health Monitoring. Advanced Materials Technologies 10, 2401782. https://doi.org/10.1002/admt.202401782 Hoffmann, K., 1989. An Introduction to Measurements using Strain Gages. Hottinger Baldwin Messtechnik. Mahmoud, H.A., Nesser, H., Mostafa, T.M., Ahmed, S., Lubineau, G., 2025. A Fully Printable Strain Sensor Enabling Highly-Sensitive Wireless Near-Field Interrogation. Advanced Science 12, 2411346. https://doi.org/10.1002/advs.202411346 Micro-Measurements (Vishay), 1985. Errors Due to Misalignment of Strain Gages (No. TN-511). Philibert, M., Yao, K., Gresil, M., Soutis, C., 2022. Lamb waves-based technologies for structural health monitoring of composite structures for aircraft applications. European Journal of Materials 2, 436–474. https://doi.org/10.1080/26889277.2022.2094839 Shen, Z., Chen, S., Zhang, L., Yao, K., Tan, C.Y., 2017. Direct-Write Piezoelectric Ultrasonic Transducers for Non-Destructive Testing of Metal Plates. IEEE Sensors Journal 17, 3354–3361. https://doi.org/10.1109/JSEN.2017.2694454 Smith-Lewis, C., Downey, A., 2023. Additively Manufactured Flexible Hybrid Electronic Sensor for Discrete Fatigue Crack Detection. https://doi.org/10.2514/6.2023-2417 Voltera Inc., 2022. Printing Strain Gauges on a Glove for Remote Hand Control | Voltera [WWW Document]. Voltera Inc. URL https://www.voltera.io/use-cases/white-papers/printing-strain-gauges-tpu-laminated-glove-remote-hand-control (accessed 4.21.25). Weng, S., Zhang, J., Gao, K., Zhu, H., Zhang, Z., Chen, C., 2025. Review on strain transfer effects based on material properties for flexible sensors in structural health monitoring. Smart Mater. Struct. 34, 053002. https://doi.org/10.1088/1361-665X/add3dd Zhao, D., Liu, T., Zhang, M., Liang, R., Wang, B., 2012. Fabrication and characterization of aerosol-jet printed strain sensors for multifunctional composite structures. Smart Mater. Struct. 21, 115008. https://doi.org/10.1088/0964-1726/21/11/115008