“…In the view of hardware, multiple tactile sensors have been developed using various sensing principles [1]- [5], e.g., capacitive, piezoelectric, optical, resistive and ultrasonic etc. In the meantime, some researchers contributed to decoding the conveyed message by the tactile sensors to retrieve the information of interacted object, such as contact locations [6], [7], slippage [8], object pose [9] and surface textures [10]- [12]. As defined in [13], the object characteristics can mainly be divided into two categories, i.e., material and geometric properties.…”