Design and Evaluation of Interaction Techniques Dedicated to Integrate Encountered-Type Haptic Displays in Virtual Environments

Encountered-Type Haptic Displays (ETHDs) represent a field of haptic displays with the premise of not using any type of actuator directly in contact with the user skin, thus providing an alternative integration of haptic displays in virtual environments. In this paper, we present novel interaction techniques (ITs) dedicated to ETHDs. The techniques aim at addressing the issues commonly presented for these devices such as limited contact areas, lags and unexpected collisions with the user. First, our paper proposes a design framework based on several parameters defining the interactive process between user and ETHD (input, movement control, displacement and contact). Five techniques based on different ramifications of the design space framework were conceived, respectively named: Swipe, Drag, Clutch, Bubble and Follow. Then, a use-case scenario was designed to depict the usage of these techniques on the task of touching and coloring a wide, flat surface. Finally, a user study based on the coloring task was conducted to assess the performance and user experience for each IT. Results were in favor of Drag and Clutch techniques which are based on manual surface displacement, absolute position selection and intermittent contact interaction. Taken together our results and design methodology pave the way to the design of future ITs for ETHDs in virtual environments.