Designed scent: tools and methods for olfactory analysis in automotive field

Aim of this research was to devise a design methodology for the evaluation and the selection of materials exclusively based on the scent. The goal was to investigate, both from a sensorial and an instrumental point of view, the scent perceived by the user. The study focused on the automotive field, an enclosed environment with frequent temperature leaps, where the user is in very close contact with materials. Studying the most critical areas of the car, the dashboard and the seat cover, twelve materials has been selected on the basis of technical characteristics and intrinsic scent. A part of these are traditionally used, such as polyurethane, imitation leather and microfiber, the others represent innovative materials used in other fields (recycled materials and materials from renewable resources). Each material was subjected to a sensory analysis, performed by a panel of 25 car users who performed several tasks based on the odor perception: liking test, CATA-test with evocative terms, evaluation of the overall intensity and olfactory recall associations. Materials were also analyzed by means of an electronic nose. The combined analysis was necessary to draw useful correspondences between the instrumental and the subjective data based on associations. By crossing the results of the dual analysis, it was possible to derive the perceptual responses of each material, hence obtaining a comparison between the traditional and innovative materials. The results confirmed that the scent could be considered a requirement in the project phases, supplying different meanings to the product. The methodology goal is to support designers in the material choice during the project phases. Due to its universal characteristics, the presented methodology could be used in different fields, for various products and materials (micro-encapsulated ones, plastics, biopolymers, paper, etc.), where scent will be planned by designers and experts.