A Flexible Pressure Sensor Based on Multiwalled Carbon Nanotubes/ Polydimethylosiloxane Composite for Wearable Electronic-Skin Application

Abstract

The multiwalled carbon nanotubes/ polydimethylosiloxane (MWCNT/PDMS) composite based pressure sensor has been widely adopted in wearable health care devices and electronic-skins due to its high flexibility, piezoresistivity, high sensitivity over a broad linear range and biocompatibility. Herein, MWCNT/PDMS composites with different MWCNT contents were fabricated and their mechanical and electrical characteristics were evaluated in detail for each case. The MWCNT/PDMS composite pressure sensors shows high sensitivity (0.02715–0.08283 kPa <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\text {-1}}$ </tex-math></inline-formula> ) over large pressure sensing range from 0.1 to 100 kPa. In addition, through the cyclic stretching test, the strain-sensing properties of the MWCNT composite shows high reliability over 1000 repetitive cycles. The flexible devices can be used as the wearable electronic skin and successfully mounted on human skin to achieve the capability of physiological stimuli monitoring, i.e., human wrist pulse wave for health care applications. The wide linear working range with high sensitivity of the MWCNT/PDMS pressure sensor makes it a potential choice in flexible electronics such as wearable devices for health care monitoring, soft robotics and E-skin application.