Interface Bonding Strategy for Soft Bioelectronics Gongwei Tian, Dan Yang, Dianpeng Qi School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, P. R.  China (email address: dpqi@hit.edu.cn) 

Abstract 

Soft bioelectronics are emerging as the new generation of wearable devices for healthcare, which  interface living tissues with electrical hardware and provide a powerful tool for the transduction of  original electrochemical/mechanical/physiological signals in living tissues to external electrical  circuits. So far, the interface adhesion between the active materials and the soft substrate, as well as  the adhesion between the devices and the biological tissues plays an important role in the  performances of the soft bioelectronics. The poor adhesion always results in the failures of the devices or the fails in signal monitoring. Therefore, in our work, we attempted to enhance the interface  adhesion by physical/chemical bonding strategies [1-4] (Figure 1), as a result, the stretchable  bioelectrodes with high stretchability (700%), good stability (20000 cycles under 100% strain) and  stable wet tissue adhesion (200 kPa) were produced. The as-prepared bioelectrode arrays were  successful in physiological signal monitoring.   

                             (a)                                                         (b)                                                                (c) 

Figure 1. (a) The SEM image of PPy nanowires burying in the soft PDMS substrates for physical bonding. (b) The adhesion strength of the interface between PPy film (with and without  nanowires) and the soft PDMS substrate. (c) The adhesion strength of chemical bonding between  soft bioelectrodes and the wet tissues (the insert one is the schematic draw of the chemical bonds) 

References

[1] Gongwei Tian, Dan Yang, Cuiyuan Liang, Yan Liu*, Jianhui Chen, Qinyi Zhao, Shuanglong  Tang, Jianping Huang, Ping Xu, Zhiyuan Liu, Dianpeng Qi* “Non-swelling Hydrogel with  Regenerable High Wet Tissue Adhesion for Bioelectronics” Adv. Mater. 2023, 35. 2212302. 

[2] Yan Niu, Gongwei Tian, Cuiyuan Liang, Tianchi Wang, Xu Ma, Guifen Gong*, Dianpeng Qi*  “Thermal-Sinterable EGaIn Nanoparticle Inks for Highly Deformable Bioelectrode Arrays” Adv.  Health. Mater., 2023, 12, 2202531. 

[3] Dianpeng Qi, Zhiyuan Liu, Yan Liu, Ying Jiang, Wan Ru Leow, Mayank Pal, Shaowu Pan, Hui  Yang, Yu Wang, Xiaoqian Zhang, Jiancan Yu, Bin Li, Zhe Yu,* Wei Wang,* and Xiaodong  Chen* “Highly Stretchable Compliant Polymeric Microelectrode Arrays for In-vivo  Electrophysiological Interfacing” Adv. Mater. 2017, 29, 1702800. 

[4] Dan Yang, Gongwei Tian, Cuiyuan Liang, Zixu Yang, Qinyi Zhao, Jianhui Chen, Cong Ma,  Ying Jiang, Na An, Yan Liu and Dianpeng Qi* “Double-Microcrack Coupling Stretchable  Neural Electrode for Electrophysiological Communication” Adv. Funct. Mater. 2023, 2300412.