International audience

Figure 1: We present a bimanual motion-coupled vibration algorithm capable of creating connected material experiences between two hands.By modulating the parameters of vibrations between the hands, our algorithm can induce material properties of elasticity while stretching A ○, flexibility while bending B○ and torsion while twisting C ○.

In Virtual Reality (VR), rendering realistic forces is crucial for immersion, but traditional vibrotactile feedback fails to convey force sensations effectively. Studies of asymmetric vibrations that elicit pseudo forces show promise but are inherently tied to unwanted vibrations, reducing realism. Leveraging sensory attenuation to reduce the perceived intensity of self-generated vibrations during user movement, we present a novel algorithm that couples asymmetric vibrations with user motion, which mimics self-generated sensations. Our psychophysics study with 12 participants shows that motion-coupled asymmetric vibration attenuates the experience of vibration (equivalent to a ∼30% reduction in vibration-amplitude) while preserving the experience of force, compared to continuous asymmetric vibrations (state-of-the-art). We demonstrate the effectiveness of our approach in VR through three scenarios: shooting arrows, lifting weights, and simulating haptic magnets. Results revealed that participants preferred forces elicited by motion-coupled asymmetric vibration for tasks like shooting arrows and lifting weights. This research highlights the potential of motion-coupled asymmetric vibrations, offers new insights into sensory attenuation, and advances force rendering in VR.

Designing vibrotactile experiences collaboratively requires communicating using multiple senses. This is challenging in remote scenarios as designers need to effectively express and communicate their intention while iteratively building and refining experiences, ideally in real-time. We formulate design considerations for collaborative haptic design tools, and propose CollabJam, a collaborative prototyping suite enabling remote synchronous design of vibrotactile experiences for on-body applications. We first outline Collab-Jam's features and present a technical evaluation. Second, we use CollabJam to understand communication and design patterns used during haptic experience design. We performed an in-depth design evaluation spanning four sessions in which four pairs of participants designed and reviewed vibrotactile experiences remotely. A qualitative content analysis revealed how multi-sensory communication is essential to convey ideas, how stimulating the tactile sense can interfere with personal boundaries, and how freely placing actuators on the skin can provide both benefits and challenges.

Beyond visual and auditory displays, tactile displays and grounded force feedback devices have become more common. Other sensory modalities are also catered to by a broad range of display devices, including temperature, taste, and olfaction. However, one sensory modality remains challenging to represent: kinesthesia – the sense of movement. Inspired by grain-based compliance illusions, we investigate how vibrotactile cues can evoke kinesthetic experiences, even when no movement is performed. We examine the effects of vibrotactile mappings and granularity on the magnitude of perceived motion; distance-based mappings provided the greatest sense of movement. Using an implementation that combines visual feedback and our prototype kinesthetic display, we demonstrate that action-coupled vibrotactile cues are significantly better at conveying an embodied sense of movement than the corresponding visual stimulus, and that combining vibrotactile and visual feedback is best. These results point towards a future where kinesthetic displays will be used in rehabilitation, sports, virtual-reality and beyond.

Compliance, the degree of displacement under applied force, is pivotal in determining the material perception when touching an object. Vibrotactile actuators can be used for creating grain-based virtual compliance, but they have poor spatial resolution and a limiting rigid form factor. We propose a novel electrotactile compliance illusion that renders grains of electrical pulses on an electrode array in response to finger force changes. We demonstrate its ability to render compliance in distinct shapes through a thin, lightweight, and flexible finger-worn interface. Detailed technical parameters and the implementation of our device are provided. A controlled experiment confirms the technique can (1) create virtual compliance; (2) adjust the compliance magnitude with grain and electrode parameters; and (3) render compliance with specific shapes. In three example applications, we present how this illusion can enhance physical objects, elements in graphical user interfaces, and virtual reality experiences.

We present vARitouch, a back-of-the-finger wearable that can modify the perceived tactile material properties of the uninstrumented world around us: vARitouch can modulate the perceived softness of a rigid object through a vibrotactile compliance illusion. As vARitouch does not cover the fingertip, all-natural tactile properties are preserved. We provide three contributions: (1) We demonstrate the feasibility of the concept through a psychophysics study, showing that virtual compliance can be continuously modulated, and perceived softness can be increased by approximately 30 Shore A levels. (2) A qualitative study indicates the desirability of such a device, showing that a back-of-the-finger haptic device has many attractive qualities. (3) To implement vARitouch, we identify a novel way to measure pressure from the back of the finger by repurposing a pulse oximetry sensor. Based on these contributions, we present the finalized vARitouch system, accompanied by a series of application scenarios.

This studio aims to collaboratively build foot augmentations, experiment with different materials and techniques, and create new designs for low-cost, wearable, and accessible devices that can be used by researchers, makers, designers, and artists. Considering the heightened focus on the human body with the rise of AR/VR/XR technologies, foot augmentation has great potential. To explore this potential, we invite researchers, designers and artists to share their applications, experiences, and ideas while designing foot augmentations. Participants will share knowledge, brainstorm ideas, and explore tools and materials for rapid prototyping. Finally, they will tinker and explore, discussing their design strategies to derive common approaches and best practices. Based on the hands-on session results, we will write a paper on design strategies for foot augmentation that will help facilitate more sustainable investigations and design of future foot interfaces.

When vibrations are synchronized with our actions, we experience them as material properties. This has been used to create virtual experiences like friction, counter-force, compliance, or torsion. Implementing such experiences is non-trivial, requiring high temporal resolution in sensing, high fidelity tactile output, and low latency. To make this style of haptic feedback more accessible to non-domain experts, we present Haptic Servos: self-contained haptic rendering devices which encapsulate all timing-critical elements. We characterize Haptic Servos’ real-time performance, showing the system latency is <5 ms. We explore the subjective experiences they can evoke, highlighting that qualitatively distinct experiences can be created based on input mapping, even if stimulation parameters and algorithm remain unchanged. A workshop demonstrated that users new to Haptic Servos require approximately ten minutes to set up a basic haptic rendering system. Haptic Servos are open source, we invite others to copy and modify our design.

With most digital devices, vibrotactile feedback consists of rhythmic patterns of continuous vibration. In contrast, when interacting with physical objects, we experience many of their material properties through vibration which is not continuous, but dynamically coupled to our actions. We assume the first style of vibration to lead to hermeneutic mediation, while the second style leads to embodied mediation. What if both types of mediation could be used to design tactile symbols? To investigate this, five haptic experts designed tactile symbols using continuous and motion-coupled vibration. Experts were interviewed to understand their symbols and design approach. A thematic analysis revealed themes showing that lived experience and affective qualities shaped design choices, that experts optimized for passive or active symbols, and that they considered context as part of the design. Our study suggests that adding embodied experiences as a design resource changes how participants think of tactile symbol design, thus broadening the scope of the symbol by design for context, and expanding their affective repertoire as changing the type of vibration influences perceived valence and arousal.