A Novel Wireless Thermal Convection Type Angular Accelerometer Integrated with an Active RFID-Tag

Five novel ideas are proposed in this paper to integrate an active RFID tag with thermal convection angular accelerometer on a flexible substrate, thus the device is a wireless sensor. The first innovative idea is that this device is without any movable parts, so it is very reliable. The second new idea is that it is made on a flexible substrate, such as plastic or polyimide, thus it can save more power. The third new idea is that the xenon gas is applied in the chamber to conduct the heat instead of the traditional Carbon dioxide. CO2 can produce oxidation effect to the heater and thermal sensors, while the xenon not. The fourth new idea is to apply a hemi-spherical chamber; it is more streamline in nature with less drag effect to ease the fluid flow and yield quicker response. The fifth new idea and the most powerful one is that the angular accelerometer is integrated with an active RFID tag on the same flexible substrate, thus the device becomes a more useful wireless sensor. Note the linearity, sensitivity, and response times of step-input angular accelerations are better for the hemi-spherical chamber filled with Xe gas. The sensitivity is 71.4°C/(rad/s2) and the response time is 60μs.