Three-Dimensional Localization of a Finger in Water Using Human Body Antenna Signals

HumTouch is a touch sensing method that leverages the electric currents of the human body generated by AC hum-noise present in the surrounding environment. This sensing principle facilitates the detection of human touch on semiconductive materials. In this study, we demonstrated the localization of a finger in a plastic tank filled with purified water. The currents emitted by the human finger were measured using eight electrodes installed in the tank to estimate the finger's position employing a kernel regression method. The average estimation errors among the three participants were 3.52, 0.55, and 0.72 cm in the depth and the other two orthogonal directions, respectively. The localization errors were negligible in the two-dimensional plane perpendicular to the depth direction; however, they were substantial in the depth direction within the water.