Acoustic resonant tensor cell for tactile sensing

In this paper we propose a new tactile sensing element, acoustic resonant tensor cell. The structure has only a spherical cavity in an elastic tactile sensor body with two fine ultrasound paths extended respectively to an ultrasound transmitter and receiver which are placed at the bottom of the elastomer. The acoustic resonant frequency of the air in the cavity has an explicit relation with the principal stresses around it, which is easily detected by the ultrasound transducers. The sensor is simple and elastic. The single structure presents useful tactile features of multidimensions. The principle and experimental results are described