Next Article in Journal
One-Step Coating Processed Phototransistors Enabled by Phase Separation of Semiconductor and Dielectric Blend Film
Previous Article in Journal
Lorentz Force Actuated Tunable-Focus Liquid Lens
Previous Article in Special Issue
A Polymer Asymmetric Mach–Zehnder Interferometer Sensor Model Based on Electrode Thermal Writing Waveguide Technology
Open AccessArticle

Printed and Flexible Capacitive Pressure Sensor with Carbon Nanotubes based Composite Dielectric Layer

Beijing Engineering Research Center of Printed Electronics, Beijing Institute of Graphic Communication, Beijing 102600, China
*
Authors to whom correspondence should be addressed.
Micromachines 2019, 10(11), 715; https://doi.org/10.3390/mi10110715
Received: 30 August 2019 / Revised: 4 October 2019 / Accepted: 20 October 2019 / Published: 23 October 2019
(This article belongs to the Special Issue Printable and Flexible Electronics for Sensors)
Flexible pressure sensors have attracted tremendous attention from researchers for their widely applications in tactile artificial intelligence, electric skin, disease diagnosis, and healthcare monitoring. Obtaining flexible pressure sensors with high sensitivity in a low cost and convenient way remains a huge challenge. In this paper, the composite dielectric layer based on the mixture of carbon nanotubes (CNTs) with different aspect ratios and polydimethylsiloxane (PDMS) was employed in flexible capacitive pressure sensor to increase its sensitivity. In addition, the screen printing instead of traditional etching based methods was used to prepare the electrodes array of the sensor. The results showed that the aspect ratio and weight fraction of the CNTs play an important role in improving the sensitivity of the printed capacitive pressure sensor. The prepared capacitive sensor with the CNTs/PDMS composite dielectric layer demonstrated a maximum sensitivity of 2.9 kPa−1 in the pressure range of 0–450 Pa, by using the CNTs with an aspect ratio of 1250–3750 and the weight fraction of 3.75%. The mechanism study revealed that the increase of the sensitivity of the pressure sensor should be attributed to the relative permittivity increase of the composite dielectric layer under pressure. Meanwhile, the printed 3 × 3 and 10 × 10 sensor arrays showed excellent spatial resolution and uniformity when they were applied to measure the pressure distribution. For further applications, the flexible pressure sensor was integrated on an adhesive bandage to detect the finger bending, as well as used to create Morse code by knocking the sensor to change their capacitance curves. The printed and flexible pressure sensor in this study might be a good candidate for the development of tactile artificial intelligence, intelligent medical diagnosis systems and wearable electronics. View Full-Text
Keywords: capacitive pressure sensor; composite dielectric; printed and flexible sensor; carbon nanotubes; percolation theory capacitive pressure sensor; composite dielectric; printed and flexible sensor; carbon nanotubes; percolation theory
Show Figures

Figure 1

MDPI and ACS Style

Guo, Z.; Mo, L.; Ding, Y.; Zhang, Q.; Meng, X.; Wu, Z.; Chen, Y.; Cao, M.; Wang, W.; Li, L. Printed and Flexible Capacitive Pressure Sensor with Carbon Nanotubes based Composite Dielectric Layer. Micromachines 2019, 10, 715.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop