Ten Little Fingers, Ten Little Toes: Can Toes Match Fingers for Haptic Discrimination?

In comparison with fingers, toes are relatively unexplored candidates for multi-site haptic rendering. This is likely due to their reported susceptibility to erroneous perception of haptic stimuli, owing to their anatomical structure. We hypothesize that this shortcoming can be mitigated by careful design of the tactile encoding to account for the idiosyncrasies of toe perception. Our efforts to design such an encoding achieved an improved perceptual accuracy of 18% for poking and 16% for vibrotactile stimuli. As we demonstrate, in this article, the resulting perceptual accuracy achieved by the proposed tactile encoding approaches that of the fingers, allowing for consideration of the toes as a practical location to render multi-site haptic stimuli.

Getting Your Hands Dirty Outside the Lab: A Practical Primer for Conducting Wearable Vibrotactile Haptics Research.

As haptics have become an ingrained part of our wearable experience, particularly through phones, smartwatches, and fitness trackers, significant research effort has been conducted to find new ways of using wearable haptics to convey information, especially while we are on-the-go. In this paper, instead of focusing on aspects of haptic information design, such as tacton encoding methods, actuators, and technical fabrication of devices, we address the more general recurring issues and "gotchas" that arise when moving from core haptic perceptual studies and in-lab wearable experiments to real world testing of wearable vibrotactile haptic systems. We summarize key issues for practitioners to take into account when designing and carrying out in-the-wild wearable haptic user studies, as well as for user studies in a lab environment that seek to simulate real-world conditions. We include not only examples from published work and commercial sources, but also hard-won illustrative examples derived from issues and failures from our own haptic studies. By providing a broad-based, accessible overview of recurring issues, we expect that both novice and experienced haptic researchers will find suggestions that will improve their own mobile wearable haptic studies.