Flexible Pressure Sensors with Combined Spraying and Self-Diffusion of Carbon Nanotubes

Xin Zhang; Lijun Lu; Wenduo Wang; Ning Zhao; Peng He; Jingquan Liu; Bin Yang

doi:10.1021/acsami.2c12240

Flexible Pressure Sensors with Combined Spraying and Self-Diffusion of Carbon Nanotubes

ACS Appl Mater Interfaces. 2022 Aug 24;14(33):38409-38420. doi: 10.1021/acsami.2c12240. Epub 2022 Aug 11.

Authors

Xin Zhang^{1

2}, Lijun Lu^{1

2}, Wenduo Wang^{1

2}, Ning Zhao³, Peng He⁴, Jingquan Liu¹, Bin Yang¹

Affiliations

¹ National Key Laboratory of Science and Technology on Micro/Nano Fabrication, Shanghai Jiao Tong University, Shanghai 200240, China.
² Department of Micro/Nano Electronics, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
³ Department of Orthodontics, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, College of Stomatology, Shanghai Jiao Tong University, National Center for Stomatology, National Clinical Research Center for Oral Diseases, Shanghai Key Laboratory of Stomatology, Shanghai 200011, China.
⁴ Science and Technology on Reactor System Design Technology Laboratory, Nuclear Power Institute of China, Chengdu 610213, China.

PMID: 35950563
DOI: 10.1021/acsami.2c12240

Abstract

High-performance wearable sensors are required for applications in medical health and human-machine interaction, but their application has limited owing to the trade-off between sensitivity, pressure range, and durability. Herein, we propose the combined spraying and self-diffusion process of carbon nanotubes (CNTs) to balance and improve these parameters with the CNTs spontaneously diffusing into the film surface before the film curing. The obtained sensor not only achieves high sensitivity (155.54 kPa^-1) and ultrawide pressure detection range (0.1-500 kPa) but also exhibits exceptional durability (over 12,000 pressure cycles at a high pressure of 300 kPa). In addition, the sensor exhibits a fast response (25 ms), good stability, and full flexibility. This process is a general approach that may improve the performance of various types of thin film piezoresistive sensors. Besides, the fabricated sensors can be flexibly scaled into sensor arrays and communicate with smart devices to achieve wireless smart monitoring. At present, the sensor shows broad application prospects in the fields of intelligent medical health and motion sensing.

Keywords: carbon nanotube self-diffusion; physiological signal monitoring; pressure sensor; sandwich-like structure; ultrahigh sensitivity; wearable electronics.