Highly stretchable and self-healing cellulose nanofiber-mediated conductive hydrogel towards strain sensing application

Yue Jiao; Ya Lu; Kaiyue Lu; Yiying Yue; Xinwu Xu; Huining Xiao; Jian Li; Jingquan Han

doi:10.1016/j.jcis.2021.04.001

Highly stretchable and self-healing cellulose nanofiber-mediated conductive hydrogel towards strain sensing application

J Colloid Interface Sci. 2021 Sep:597:171-181. doi: 10.1016/j.jcis.2021.04.001. Epub 2021 Apr 5.

Authors

Yue Jiao¹, Ya Lu¹, Kaiyue Lu², Yiying Yue³, Xinwu Xu², Huining Xiao⁴, Jian Li⁵, Jingquan Han⁶

Affiliations

¹ College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China; Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, China.
² College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China.
³ Biology and Environment College, Nanjing Forestry University, Nanjing 210037, China.
⁴ Chemical Engineering Department, New Brunswick University, Fredericton, New Brunswick E3B 5A3, Canada.
⁵ Material Science and Engineering College, Northeast Forestry University, Harbin 150040, China.
⁶ College of Materials Science and Engineering, Nanjing Forestry University, Nanjing 210037, China; Co-Innovation Center of Efficient Processing and Utilization of Forest Resources, Nanjing Forestry University, Nanjing 210037, China. Electronic address: hjq@njfu.edu.cn.

PMID: 33866209
DOI: 10.1016/j.jcis.2021.04.001

Abstract

Hypothesis: Hydrogel-based sensors have attracted considerable attention due to potential opportunities in human health monitoring when both mechanical flexibility and sensing ability are required. Therefore, the integration of excellent mechanical properties, electrical conductivity and self-healing properties into hydrogels may improve the application range and durability of hydrogel-based sensors.

Experiments: A novel composite hydrogel composed of polyaniline (PANI), polyacrylic acid (PAA) and 2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)-oxidized cellulose nanofibrils (TOCNFs) was designed. The viscoelastic, mechanical, conductive, self-healing and sensing properties of hydrogels were studied.

Findings: The TOCNF/PANI/PAA hydrogel exhibits a fracture strain of 982%, tensile strength of 74.98 kPa and electrical conductivity of 3.95 S m^-1, as well as good mechanical and electrical self-healing properties within 6 h at ambient temperature without applying any stimuli. Furthermore, owing to the high sensitivity of the TOCNF/PANI/PAA-0.6 hydrogel-based strain sensor (gauge factor, GF = 8.0), the sensor can accurately and rapidly detect large-scale motion and subtle localized activity. The proposed composite hydrogel is as a promising material for use as soft wearable sensors for health monitoring and smart robotics applications.

Keywords: Cellulose nanofibers; Hydrogel; Mechanical property; Polyaniline; Self-healing; Strain sensor.