Micro Capacitive Inclination Sensor Utilizing Dielectric Nano-Particles

Abstract

We have developed a micro capacitive inclination sensor that has an outer dimension of 5 mm x 5 mm x 1 mm and a linear analog output. This sensor is unique in two ways. Firstly, we have selected a method to improve the permittivity of the dielectric oil by mixing it with dielectric nano-particles. This method allows us to achieve miniaturization and high performance of the sensor easily. The second feature is the adoption of a slit structure and a pseudo channel in order to mitigate the influence of the surface tension of the dielectric oil. We have succeeded in improving the permittivity by 50% by mixing the dielectric oil with BaTiO3 nano-particles 30 nm in diameter at a rate of 15% Volume. In addition, as a result of assessing the sensor fabricated, we obtained a linear and analog output within an inclination angle range from -45 ~+45 deg. The detection resolution and the response speed were 0.1 deg or more and 0.79 sec/deg respectively. Based on these achievements, we attained a certain perspective to miniaturize inclination sensors while maintaining their performance at the level of conventional ones.