Wireless Temperature Sensor Based on a Nematic Liquid Crystal Cell as Variable Capacitance

Sensors (Basel). 2018 Oct 12;18(10):3436. doi: 10.3390/s18103436.

Abstract

Wireless communication is growing quickly and now allows technologies like the Internet of Things (IoT). It is included in many smart sensors helping to reduce the installation and system costs. These sensors increase flexibility, simplify deployment and address a new set of applications that was previously impossible with a wired approach. In this work, a wireless temperature sensor based on a nematic liquid crystal as variable capacitance is proposed as a proof of concept for potential wearable applications. Performance analysis of the wireless temperature sensor has been carried out and a simple equivalent circuit has been proposed. Sensor prototype has been successfully fabricated and demonstrated as the beginning of new biomedical sensors.

Keywords: capacitive sensor; equivalent circuit; impedance analysis; nematic liquid crystal; simulation; temperature dependence.