Nathaniel A. Caswell’s research while affiliated with University of Utah and other places

This paper presents the design of a game controller with integrated skin stretch feedback, a new form of touch feedback. This form of feedback can be used to provide directional information, as well as tactile gaming effects to a user through the input thumb joysticks. Prior testing has shown that a user can perceive and respond to single direction cues given through skin stretch feedback at the thumb joysticks. This paper presents further experiments to characterize user interaction and responses to feedback as a function of the relative timing between skin stretch cues given on both of the controller's thumb joysticks.

This paper presents the design and development of handheld gaming devices that provide a new form of touch feedback: skin stretch feedback. Our prior work showed 1-1.5 mm of skin stretch applied to the fingertips (or thumb tips) could provide direction cues with high accuracy. The direction of each cue corresponded to the direction of applied skin stretch. Haptic feedback via tactile skin stretch can be used to provide tactile gaming effects and directional information through the same interface used for game inputs. Tests conducted with devices that resemble modern game controllers indicated which grip style is preferred by users and how to present direction cues to achieve the highest recognition rates. The main contribution of this paper is to show an initial demonstration of the benefits of skin stretch feedback in a multimodal gaming scenario.

This paper presents the design and initial characterization of a video game controller prototype with tactile skin stretch displays embedded into its thumb joysticks. This work builds on previous work using lateral skin stretch at a single fingertip to provide direction cues. Our game controller allows a gamer to receive directional tactile feedback through the same interface he/she makes game inputs, and has the potential to enhance the gaming experience. Direction cues correspond to the direction of applied skin stretch. Modern game controllers typically have users angle their thumbs diagonally inwards to reach the joysticks, however, this may affect the cognition of skin stretch cues. Testing with a game controller prototype that allows for both forward and angled alignment of the user's thumbs shows no significant difference in accuracy or response time due to thumb orientation. Our results show no significant reduction in performance due to the required mental rotation of stimuli delivered in the angled thumb configuration. Furthermore, the angled thumb configuration appears to have ergonomic advantages. A more integrated game controller prototype is in development, which will permit further human factors testing to examine effects such as stimulus masking.

Haptic devices have the ability to convey information to users through touch. Often, this method of communication can be preferable to more traditional means of communication, such as visual or audio displays. For example, a haptic device could provide directional skin stretch to communicate navigational cues as an alternative to audio commands. Prior work has shown that directional skin stretch applied on the fingertips can be accurately recognized with displacements less than 0.2 mm. While the fingertips excel at accurately discerning direction cues, it is often desirable to leave the fingers unencumbered for other tasks. This desire has motivated an effort to explore other locations to which direction cues can be applied. Studies of human sensitivity indicate that the hand or forearm may be a good location for skin stretch cues. Based on this information, a portable device was designed that applies direction cues to the forearm. The process of designing this device began with testing to estimate the magnitude of skin stretch required to accurately convey direction cues for a variety of forearm and hand locations. Based on these results, a forearm-mounted skin stretch prototype capable of 2 mm skin displacements was designed and fabricated. A qualitative evaluation of an initial prototype contributed several useful insights that aided in the design of the final device prototype.