3D Printed Capacitive Tilt Sensor

Abstract

This work presents 3D printed tilt sensor to measure fluid level and tilt sensing in robotics. It comprises of four 3D printed interdigitated capacitive sensors printed as a single structure and immersed in liquid $\mathrm{E}\mathrm{c}\mathrm{o}\mathrm{f}\mathrm{l}\mathrm{e}\mathrm{x}^{\mathrm{T}\mathrm{M}}$ (part A only). When the orientation of the sensor changes, the level of fluid in contact with the sensors also changes and this causes a change in the capacitance. The sensors were first printed individually and change in capacitance measured for different fluid levels. The response of the individual capacitive sensors shows a stable response for a dip and remove cyclic test in fluid at frequency of 0. 625Hz. The results of the tilting experiments show a relative change in capacitance ($\Delta$ ClC $\theta$ $\sim$ 0.1% per degree for an angle range of $\sim-20^{0}$ to $\sim+20^{0}$. With $\sim$ $6.7^{0}$ detected per mm of the level of fluid in contact with the sensor, the result shows the capability to achieve a measurement range of at least $\sim\pm 93.8^{0}$ (for a sensor of length of $\sim$12mm). The study carried out in this work finds application in tilt sensing in robotics as well as in fluid-level sensing in which case the sensor could be printed as part of the structure of the fluid container.