Designing for the tactile sense: investigating the relation between surface properties, perceptions and preferences

Abstract

The main aim of the case study described in this paper was to gain further knowledge of tactile product properties, in particular the relation between engineering properties and perceived qualities of surface structures. A second aim was to assess the usefulness of a tool for eliciting a sensory profile according to 10 attributes. Three experimental studies have been completed: the engineering characteristics of six surface textures have been obtained through surface profilometry and stick-slip tests; the perceived tactile properties of the same surfaces have been assessed according to 10 descriptors; elicited tactile requirements for the surfaces of three different products (the barrel of a pen, a chair, a steering wheel) have been compared with the sensory profiles of the six materials in order to predict customer preferences; and predicted preferences have been compared with actual. The results show that the agreement between objective measurements and perceived properties (attributes) varies, partly due to some attributes being difficult to understand. The results also show that customers can express requirements for tactile properties of products. However, the predicted ‘best samples’ did not altogether agree with actual choices. Part of the explanation for this can be attributed to the subjects' integrated assessments of visual and tactile impressions. Also people integrate their assessment of different attributes, and judge the attributes' abilities to meet the (sometimes conflicting) requirements, in different ways. The way different attributes and qualities are integrated in the assessments and preferences of individuals are a matter for further research.

Keywords:

• Product design
• Tactile properties

Acknowledgements

The authors wish to express their gratitude to Ph.D. Henrik Westberg and Professor Mikael Rigdahl of the Department of Materials and Manufacturing Technology at Chalmers University of Technology, for their support in completing this case study, in particular when carrying out and interpreting the results of study I, and also to Ms. Sofie Ignell and Volvo Cars for providing the material samples and access to the stick-slip test equipment in study I.