EXPERIMENTAL SETUP FOR VISUAL AND TACTILE EVALUATION OF MATERIALS AND PRODUCTS THROUGH NAPPING® PROCEDURE

Selection and definition of materials surfaces in product design can be driven by the sensory effect conceived. Certain characteristics that can be perceived through the sense of vision can also be perceived through the sense of touch. As a consequence, the sense of touch also plays an important role in functional user-product interactions. In this paper, a specific setup dedicated to Napping® evaluation with a focus on visual and tactile modalities is presented, using untrained subjects. This procedure allows highlighting the main perceptions the subjects have about the materials. It enables to rank the sample attributes that are perceived by the subjects when different sensory modalities are used. In particular visual-tactual incongruity can be highlighted, which can be of interest in product design. For instance, with our set of materials, in tactile perception, the primary axis clearly opposes slick and scratchy perceptions. In the visual test, the samples exhibiting large features are clearly set apart from samples exhibiting no features (slick). The other samples are gathered in between. In the visuo-tactile test, a hybrid perception is observed