Smart materials are materials that change properties according to stimuli, adapting to their environment. This aspect make them particularly interesting, to help to increase the performance of the objects, and to enable new functionalities and new ways to interact with users. Some smart materials can affect the perception we have of the objects. The existing smart materials have an action mostly on the visual and the tactile aspects. The most popular variations are based on color changing materials, such as thermo/photo-chromic materials or thermo/photo-luminescent ones and shape changing materials, such as shape memory alloys. These new materials will allow designers to introduce new sensory experiences in their products. But for that, they need to know what differentiate these materials from common ones, which kinds of smart material exist, and have some clues about how they can be used. This paper present a classification of smart materials, as well as some of the applications of color and shape changing materials