Integrating Thermal Convection Non-Floating Type Inclinometer and RFID Tag

Abstract

This research proposes a novel wireless RFID-based thermal convection type inclinometer design. Five new ideas are presented. The first one is to make the device on a flexible substrate, thus it can save more energy than the traditional silicon. The second one is to integrate both an inclinometer and a wireless RFID antenna on the same substrate, such that it is very convenient for usage. The third and the fourth ideas are to fill xenon gas in the chamber with hemi-cylindrical shape instead of the previous one with carbon dioxide and rectangular shape. Because the xenon gas would not produce oxidization effect to the heater, and it is more reliable. Besides, the xenon gas can increase the gas molecular weight and the device sensitivity. The fifth idea is to use non-floating structure instead of the floating one with a cavity in the substrate. Moreover, to increase the sensitivity the thermisters were stacked on one material such as alumina nitride. Note that the sensitivity curves by applying the non-floating structure with stacking material are more linear. Three kinds of stacking height were studied, such as 1, 1.5 and 2mm. One can see the combinations of AlN/Xenon are always better. If the largest sensitivity is the key consideration, then H2=1.5mm is the best choice (0.4°C/Degree), but the linear operating range is 45°. However, If the largest linear operating range is the requirement, then H2=2mm is the best one (75°), but the sensitivity is 0.173°C/Degree.