Proximity distance estimation based on capacitive coupling between 1mm3 sensor nodes

We are working toward actualizing a real-time 3D modeling system. It uses a sensor network that distributes many 1 mm³-class sensor nodes in plastic clay. The distributed sensors sense distances between them, and the sensor network collects the distance information for recognizing object shape by calculating relative positions of nodes based on the collected node-to-node distances. This paper proposes a distance estimation method based on capacitive coupling between sensor nodes for the 3D modeling system. An electrical signal is transmitted through a closed loop composed of node-to-node capacitive coupling, and the signal attenuation is used for the distance estimation. We investigate gain and directivity of the signal transmission with electric field and circuit simulation to explore appropriate electrode designs for the proposed method and evaluate the feasibility of the node localization with the proposed distance estimation method.