Design and Evaluation of Mid-Air Haptic Interactions in an Augmented Reality Environment

Augmented Reality mid-air environments are currently re-evaluating the interaction principles of the objects rendered in space. The surface, texture complexity, compliances and dynamics can be represented through volumetric rendering, comprised of shape, size and/or volume. Haptic representation of the graphical content and the dynamics of the interface can be tailored to the application requirements. The solution, however, is highly dependent on the tasks and the need for tactile feedback. The ideal system must blend the right level of factors and attributes to maximize user performance and satisfaction. The mechanics and perceptual correlation of mid-air haptics are still unresolved. Based on human tactile limitations, the prime classification of the tactile interactions was proposed, based on spatial and temporal requirements and limitations. Proposed classes are intuitive and proved to be easily adapted to many interactions, as well as compatible with gesture recognition. This paper discusses the haptic design criteria for mid-air, tactile-enhanced interactions suitable for interface AR applications. Design evaluation involved a sequence of six scenes, directed to engage user attention and strengthen performance. Proposed solution and its influence on ergonomics and efficiency, were subjected to user cognitive evaluation. A non-contact, interactive demo, blending cross modal stimulations, combining vision, auditory and tactile sensations was produced, and user studies were discussed.