Highly transparent, stretchable, and rapid self-healing polyvinyl alcohol/cellulose nanofibril hydrogel sensors for sensitive pressure sensing and human motion detection

Xin Jing, Heng Li, Hao Yang Mi, Yue Jun Liu, Pei Yong Feng, Yi Min Tan, Lih Sheng Turng

Research output: Journal article publicationJournal articleAcademic researchpeer-review

69 Citations (Scopus)

Abstract

Wearable sensors have emerged as favored novel devices for human healthcare. Current sensors, however, suffer from low sensitivity, non-transparency, and lack of self-healing ability. In this study, we synthesized a polyvinyl alcohol/cellulose nanofibril (PVA/CNF)hydrogel with dual-crosslinked networks for highly transparent, stretchable, and self-healing pressure and strain sensors. The hydrogel contains dynamic borate bonds, metal–carboxylate coordination bonds, and hydrogen bonds, all of which contribute to the hydrogel's superior dimensional stability, mechanical strength and flexibility, and spontaneous self-healing ability as compared to traditional PVA hydrogels. The developed hydrogel has a moderate modulus of 11.2 kPa, and a high elongation rate of 1900%. It spontaneously self-heals within 15 s upon contact without any external stimuli, has a high transmittance of over 90%, and has excellent compatibility with human fibroblasts. The capacitive sensor developed based on the PVA/CNF hydrogel has high sensitivity to very subtle pressure changes, such as small water droplets. When used as a strain sensor, it was capable of detecting and monitoring various human motions such as finger, knee, elbow, and head movements, breathing, and gentle tapping. The developed hydrogel and sensors not only show great potential in electronic skin, personal healthcare, and wearable devices, but may also inspire the development of transparent, intelligent skin-like sensors.

Original languageEnglish
Pages (from-to)159-167
Number of pages9
JournalSensors and Actuators, B: Chemical
Volume295
DOIs
Publication statusPublished - 15 Sep 2019

Keywords

  • High sensitivity
  • Self-healing
  • Stretchable hydrogel
  • Transparent

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Instrumentation
  • Condensed Matter Physics
  • Surfaces, Coatings and Films
  • Metals and Alloys
  • Electrical and Electronic Engineering
  • Materials Chemistry

Cite this