Next Article in Journal
Quantifying Efficacy and Limits of Unmanned Aerial Vehicle (UAV) Technology for Weed Seedling Detection as Affected by Sensor Resolution
Previous Article in Journal
Interstitial Photoacoustic Sensor for the Measurement of Tissue Temperature during Interstitial Laser Phototherapy
Article Menu

Export Article

Open AccessArticle
Sensors 2015, 15(3), 5594-5608; doi:10.3390/s150305594

Temperature-Phase Converter Based on a LC Cell as a Variable Capacitance

Displays and Photonic Applications Group, Department of Electronic Technology, Carlos III University of Madrid, Avenida de la Universidad 30, Leganés E28911, Spain
*
Author to whom correspondence should be addressed.
Academic Editor: Vittorio M.N. Passaro
Received: 19 December 2014 / Revised: 25 February 2015 / Accepted: 2 March 2015 / Published: 6 March 2015
(This article belongs to the Section Physical Sensors)
View Full-Text   |   Download PDF [919 KB, uploaded 6 March 2015]   |  

Abstract

The main characteristic of liquid crystals is that their properties, both electrical and optical, can be modified through a convenient applied signal, for instance a certain voltage. This tunable behavior of liquid crystals is directly related to the orientation of their nanometric components with respect to a director direction. However, the initial alignment is a fabrication-dependent parameter and may be either planar or homeotropic. In addition, the strong dependence of the properties of liquid crystals with the temperature is well known and widely used for several temperature sensors. This dependence is produced by the influence of the temperature on the ordering of the molecules. In this work, we have studied the temperature dependence of the electric properties of a liquid crystal cell, in particular the dielectric permittivity, with the temperature as a function of the initial alignment set during the fabrication process. Starting from experimental measurements, an equivalent circuit model including the temperature dependence has been proposed. We have observed that a good linearity in a wide temperature range is provided at a suitable exciting frequency. Finally, a proper conditioner circuit is proposed as a powerful tool for linear and high sensibility temperature measurement. View Full-Text
Keywords: nematic liquid crystal; impedance analysis; temperature dependence; equivalent circuit; capacitive sensor; simulation nematic liquid crystal; impedance analysis; temperature dependence; equivalent circuit; capacitive sensor; simulation
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Torres, J.C.; García-Cámara, B.; Pérez, I.; Urruchi, V.; Sánchez-Pena, J.M. Temperature-Phase Converter Based on a LC Cell as a Variable Capacitance. Sensors 2015, 15, 5594-5608.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Sensors EISSN 1424-8220 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top