Design of a Temperature Micro-Sensor with a Gaseous Fluid Flow

Non-intrusive Liquid Crystal Thermography technique (LCT) has been proven as a powerful tool for lowtemperature application in micro-scale systems. It provides high-spatial resolution temperature maps dependent on colour response of heated thermo-chromic liquid crystal material (TLC). Different types of TLCs have been widely used in form of coated paints or water-based droplets in aqueous carrier fluid. Up to now, suitable designs of micro-devices with specific features optimized for their use in the presence of gas micro-flows has still not being proposed. Therefore, the study of a design of single channel micro-device for liquid-gas mixing is presented here. Research work has been performed experimentally and/or numerically to investigate the effect of various geometric designs of micro-devices to provide uniformly distributed TLC particles along a gas flow and to avoid their sedimentation. Beside the geometric design, material and heating systems are of high importance in order to achieve desirable observation of temperature gradients along the channel. Moreover, the flow rate and shear stress inside the channel were set to be minimal due to suspected high sensitivity of TLCs. This paper is intended to bring new insights and fresh perspectives to the development of temperature microscale sensors for practical implementation in the future.