Low viscosity and highly flexible stereolithographic 3D printing resins for flexible sensors

• Published in: Materials & design 2024-07, Vol.243, p.113052, Article 113052
• Main Authors: Wang, Dongmei, Wang, Rui, Chen, Shaoyun, Gao, Jianhong, Cai, Cuifang, Zheng, Yanyu, Liu, Xiaoying, Qu, Bo, Chen, Nairong, Zhuo, Dongxian
• Format: Article
• Language: English
• Subjects: Elastomers; Flexible tactile sensors; Low viscosity; Organosilicon; Photocurable 3D printing; Polyurethane
• ISSN: 0264-1275
• DOI: 10.1016/j.matdes.2024.113052

[Display omitted] •A low-viscosity photosensitive resin system containing PU segments and PDMS segments was prepared.•The photosensitive resin systems had good 3D printing accuracy and the resultant cured photosensitive resin possess excellent flexibility and elasticity.•The flexible sensors prepared with photosensitive resin exhibit high signal sensitivity and stability. Flexible sensors show the wide range of applications in electronic products. However, challenges remain in developing sensors with internal complex construction, excellent flexibility, elasticity and strength. In this paper, a prepolymer (PU-PDMS-OH-HEMA) contain polyurethane (PU) segments and polysiloxane (PDMS) segments was synthesized, and the photosensitive resins with low viscosity for 3D printing were prepared by mixing prepolymers with diluents and photoinitiators. The resultant cured photosensitive resins showed the improved mechanical properties. The PDMS-OH-30 sample exhibit the excellent mechanical properties, with tensile strength and elongation at break of 10.03 MPa and 1046.15 %, respectively, and the resin viscosity of 62 cP. Conductive ionic liquids were added to the above photosensitive resins to prepare flexible sensors, which show the electrical sensitivity and stability. The findings in the work propose a contribution to the development of highly flexible 3D printing resins for fabricating flexible sensors.