{Spatial Tactile Feedback Support for Mobile Touch-screen Devices

• Main Author: Yatani, Koji
• Other Authors: Truong, Khai N.
• Language: en_ca
• Published: 2011
• Subjects: Mobile device; Tactile feedback; Touch screen; User Interface; 0984
• Online Access: http://hdl.handle.net/1807/31983

Mobile touch-screen devices have the capability to accept flexible touch input, and can provide a larger screen than mobile devices with physical buttons. However, many of the user interfaces found in mobile touch-screen devices require visual feedback. This raises a number of user interface challenges. For instance, visually-demanding user interfaces make it difficult for the user to interact with mobile touch-screen devices without looking at the screen---a task the user sometimes wishes to do particularly in a mobile setting. In addition, user interfaces on mobile touch-screen devices are not generally accessible to visually impaired users. Basic tactile feedback (e.g., feedback produced by a single vibration source) can be used to enhance the user experience on mobile touch-screen devices. Unfortunately, this basic tactile feedback often lacks the expressiveness for generating vibration patterns that can be used to convey specific information about the application to the user. However, the availability of richer information accessible through the tactile channel would minimize the visual demand of an application. For example, if the user can perceive which button she is touching on the screen through tactile feedback, she would not need to view the screen, and can instead focus her visual attention towards the primary task (e.g., walking). In this dissertation, I address high visual demand issues found in existing user interfaces on mobile touch-screen devices by using spatial tactile feedback. Spatial tactile feedback means tactile feedback patterns generated in different points of the user's body (the user's fingers and palm in this work). I developed tactile feedback hardware employing multiple vibration motors on the backside of a mobile touch-screen device. These multiple vibration motors can produce various spatial vibration patterns on the user's fingers and palm. I then validated the effects of spatial tactile feedback through three different applications: eyes-free interaction, a map application for visually impaired users, and collaboration support. Findings gained through the series of application-oriented investigations indicate that spatial tactile feedback is a beneficial output modality in mobile touch-screen devices, and can mitigate some visual demand issues.