Skin-adhesive lignin-grafted-polyacrylamide/hydroxypropyl cellulose hydrogel sensor for real-time cervical spine bending monitoring in human-machine Interface

• Published in: International journal of biological macromolecules Vol. 247; p. 125833
• Main Authors: Chen, Ying, Lv, Xiaowei, Wang, Yushu, Shi, Jingyi, Luo, Sihan, Fan, Junjiang, Sun, Bo, Liu, Yupeng, Fan, Quli
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 30.08.2023
• Subjects: Bridge-like structure; Conductive hydrogel; Self-healing; Bridge-like structure; Conductive hydrogel; Self-healing
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2023.125833

Developing a straightforward method to produce conductive hydrogels with excellent mechanical properties, self-adhesion, and biocompatibility remains a significant challenge. While current approaches aim to enhance mechanical performance, they often require additional steps or external forces for fixation, leading to increased production time and limited practicality. A novel lignin-grafted polyacrylamide/hydroxypropyl cellulose hydrogel (L-g-PAM/HPC hydrogel) with a semi-interpenetrating polymer network structure had been developed in this research that boasted exceptional adhesion to the skin (∼68 kPa) and stretchability properties (∼1637 %) compared to PAM-based hydrogels. By incorporating conductive additives such as silver nanowires and carbon nanocages to construct a bridge-like structure within the hydrogel matrix, the resulting AgC@L-g-PAM/HPC hydrogel exhibited impressive electrical conductivity, surpassing that of other PAM-based hydrogels relying on MXene, with a maximum value of 0.76 S/m. Furthermore, the AgC@L-g-PAM/HPC hydrogel retained its efficient electrical signal transmission capability even under mechanical stress. These make it an ideal flexible strain sensor capable of detecting various human motions. In this study, a smart real-time monitoring system was successfully developed for tracking cervical spine bending, serving as an extension for monitoring human activities. •A hydrogel with a semi-IPN structure that displayed remarkable adhesion and stretchability•A bridge-like structure that provided the hydrogel with impressive conductivity•A smart real-time monitoring system for tracking cervical spine bending