J. Mater. Sci. Technol. ›› 2020, Vol. 45: 241-247.DOI: 10.1016/j.jmst.2019.11.014

• Research Article • Previous Articles    

Facilely prepared layer-by-layer graphene membrane-based pressure sensor with high sensitivity and stability for smart wearable devices

Tao Liua,b, Caizhen Zhub, Wei Wua,c, Kai-Ning Liaod, Xianjing Gonga, Qijun Suna, Robert K.Y. Lia,*()   

  1. a Department of Materials Science and Engineering, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong, China
    b Institute of Low-dimensional Materials Genome Initiative, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, China
    c National Engineering Research Center of Novel Equipment for Polymer Processing, Key Laboratory of Polymer Processing Engineering of Ministry of Education, School of Mechanical and Automotive Engineering, South China University of Technology, Guangzhou, 510640, China
    d State Key Laboratory of Organic-Inorganic Composites, College of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing, 100029, China
  • Received:2019-09-21 Revised:2019-10-22 Accepted:2019-11-02 Published:2020-05-15 Online:2020-05-27
  • Contact: Robert K.Y. Li

Abstract:

With the prosperous development of artificial intelligence, medical diagnosis and electronic skins, wearable electronic devices have drawn much attention in our daily life. Flexible pressure sensors based on carbon materials with ultrahigh sensitivity, especially in a large pressure range regime are highly required in wearable applications. In this work, graphene membrane with a layer-by-layer structure has been successfully fabricated via a facile self-assembly and air-drying (SAAD) method. In the SAAD process, air-drying the self-assembled graphene hydrogels contributes to the uniform and compact layer structure in the obtained membranes. Owing to the excellent mechanical and electrical properties of graphene, the pressure sensor constructed by several layers of membranes exhibits high sensitivity (52.36 kPa-1) and repeatability (short response and recovery time) in the loading pressure range of 0-50 kPa. Compared with most reported graphene-related pressure sensors, our device shows better sensitivity and wider applied pressure range. What’s more, we demonstrate it shows desired results in wearable applications for pulse monitoring, breathing detection as well as different intense motion recording such as walk, run and squat. It’s hoped that the facilely prepared layer-by-layer graphene membrane-based pressure sensors will have more potential to be used for smart wearable devices in the future.

Key words: Graphene membrane, Self-assembly, High sensitivity, Wearable devices, Human motions