The tactile window; a haptic tool for material selection

Abstract

This report presents the design of a haptic tool for designers. The tool should aid them in material selection for product experience and fit in an advanced design studio known as the Tangible Virtual Reality environment. The field of haptics and existing haptic devices were studied, as well as the Tangible Virtual Reality environment. Additionally, insights in designer’s needs for this task were sought. The results from these analyses suggest that existing devices are somewhat ineffective because they do not give multi-sensation feedback. Multi-sensation stimulation is what occurs in real life: when touching an object, people feel several characteristics like warmth, texture and softness simultaneously. Six characteristics are deemed important to designers. Consequently, a tool mimicking materials should provide a similar experience. Based on the multi-sensation theory, a solution idea, called the tactile window, was developed. The solution idea describes the intended behaviour, functionalities and possibilities of the design. Given this vision of what the design should be like, technologies that could achieve this were sought, and the possibilities to combine them explored. To contain the complexity, only two of the six relevant material characteristics, texture and warmth, were included in the first concept. The first is simulated using an array of vibrating pins driven by piezo benders, the second with a peltier element acting as a heat pump. The integration of the four other relevant material characteristics falls outside the scope of this project. To prove the feasibility of the concept, a prototype was built and tested. The functionality was evaluated with a simple matching experiment: nine designers and design students matched virtual materials displayed on the prototype to real material samples. The test results seem to confirm the multi-sensation theory. The prototype is able to give the impression of a certain surface, but the absence of four of the essential characteristics makes for virtual materials that are not considered one hundred percent realistic. Also, the algorithms for displaying texture and warmth need refinement. In general, the results of this project are promising. However, further testing with the existing prototype as well as further integration of material characteristics is recommended.