Capacitive Based Liquid Crystal Chemical and Biological Sensors

Abstract

This paper demonstrates the principle of capacitive sensing in liquid crystal (LC) based sensors with potential applications to chemical and biological systems. The theory for tracking the average molecular deformation partially disorder LC film via capacitive sensing is investigated. Three capacitance measurements are required to track the average molecular orientation as well as the degree of disorder in the LC film. Sensors' outputs are digitized by involving capacitance to digital converter to be applied to computerized applications. Both the experimental and calculated capacitances of a selected sensor structure are presented.

Sensing Characteristics of Chemical Agents by Using Liquid Crystal-Based Chemical and Biological Sensors

“…To verify these transitions of NLCs, we have the optical observation, which is observed visual inspection or optical microscopy as well as the electrical observation, which is measured the capacitance provided by ability to identify and track the average transition. [4][5][6] This sensor structure by the gold micro-electroplating technique is quite useful to steadily support a 10μm thickness of NLCs.…”