Design and research project of a foot-based haptic feedback (FBHF) device, StepSense, which enables vibrotactile and thermal stimulation. The findings of this project contribute to the advancement of FBHF devices and their potential to enhance immersion and presence in virtual reality (VR) systems.
As a pre-study to learn and analyze the research around foot haptics, we conducted a systematic literature review on the area. The process helped us to see the overall trend of research and to find the gap in the research that we wanted to work on.
Based on the scope we decided through pre-study, we started to explore concepts through various ideation methods.
Brainstorming
To deep dive into exploring the concept of our design and research, the team gathered for a focused one-day design sprint. During this collaborative session, we engaged in multiple brainstorming sessions and produced a multitude of sketches to crystallize our ideas. The decision to adopt a form similar to a foot sole emerged as the consensus, driven by the aim of facilitating seamless device implementation and ensuring user-friendly intuitiveness.
Tactile Workshop
To deepen our understanding of how the foot perceives various materials and haptic stimuli, we conducted a tactile workshop as a part of our design sprint. This hands-on session involved the exploration of tactile stimulation using different objects, the discernment of vibrations through varied motors, and the experience of thermal sensations using diverse heat pads. The workshop yielded valuable insights, leading us to identify the most effective sensory modalities for the foot within the VR environment—specifically, vibrotactile and thermal stimulations.
Guided by our chosen concept, we started building our first prototype by incorporating force sensors as inputs, along with a heat pad and six distinct vibration motors, used as outputs. Concurrently, we crafted a virtual reality (VR) environment featuring hot asphalt, gravel, and sand to assess the device's impact on user experience and immersion.
In pursuit of concept validation and experimental refinement, we executed a pilot study, wherein external participants engaged with the device to evaluate its informative capabilities. The findings revealed that the deployment of six vibration motors proved excessive, hindering the distinction of effects.
Subsequently, we refined the design, opting for four motors strategically arranged based on the relative locations of the active vibrotactile senses in our feet. Simultaneously, adjustments were made to the VR materials to align with the sensations felt through our thermal stimulation and vibrotactile design, enhancing the overall coherence of the immersive experience.
Mixed Method