Haptixel: Encoding Data through Cutaneous Force-based Encountered-Type Fingertip HapticsData visualization benefits from non-visual cues to enable people to understand information by engaging with it through multimodality, yet most approaches rely on cumbersome technologies or large scale artifacts, making them difficult to adapt to dynamic or complex datasets. In this paper, we explore the use of cutaneous haptics as a lightweight quantitative channel for visualization tasks, allowing users to feel data and interact with it dynamically. We present Haptixel, an open-source DIY encountered-type wearable providing force-feedback on the users' fingertips' pulp. We propose an interaction framework illustrating how Haptixel can be used to complement visualization tasks through combinations of force levels and contact types. We evaluate our approach in a pixel-art-like VR user study (n=16) where pixels color/height are associated to forces as a univariate value mapping. Results show that participants can retrieve information with Haptixel, and significantly discriminate 3D-data with at least four levels of forces; suggesting that cutaneous force-feedback can function for quantitative distinctions in visualization tasks.2026EBElodie Bouzbib et al.Universidad Publica de NavarraForce Feedback & Pseudo-Haptic WeightInteractive Data VisualizationImmersion & Presence ResearchCHI
StreamFog: Using ultrasonic streaming for controlling aerosols in fog-based displaysFog screens are a projection medium for mid-air graphics, they are see-through and reach-through. Fog screens are traditionally generated by laminar flows coming out of linear outlets and thus are usually static. Here, we show that ultrasonic beams create a streaming field of constrained airflow that direct aerosols in a fast and controllable way. We characterize various aerosols under streaming and optical diffusion, and evaluate control methods for obtaining different aerosol shapes. Aerosol columns are raised, moved and pushed in a few hundred milliseconds to serve as a projection medium. Hands and other objects do not disturb the fog columns significantly, allowing for direct interaction. We showcase applications by projecting on multiple columns that can be moved continuously within the display volume, reach-through interactions and mixed-reality for tabletop games.2026UFUnai Javier Fernández et al.Universidad Pública de NavarraMid-Air Haptics (Ultrasonic)Physical-Digital Hybrid InteractionTabletop Tangible InteractionCHI
Heartbeat Resonance: Inducing Non-contact Heartbeat Sensations in the ChestPerceiving and altering the sensation of internal physiological states, such as heartbeats, is key for biofeedback and interception. Yet, wearable devices used for this purpose can feel intrusive and typically fail to deliver stimuli aligned with the heart’s location in the chest. To address this, we introduce Heartbeat Resonance, which uses low-frequency sound waves to create non-contact haptic sensations in the chest cavity, mimicking heartbeats. We conduct two experiments to evaluate the system's effectiveness. The first experiment shows that the system created realistic heartbeat sensations in the chest, with 78.05 Hz being the most effective frequency. In the second experiment, we evaluate the effects of entrainment by simulating faster and slower heart rates. Participants perceived the intended changes and reported high confidence in their perceptions for +15% and -30% heart rates. This system offers a non-intrusive solution for biofeedback while creating new possibilities for immersive VR environments.2025WHWaseem Hassan et al.University of Copenhagen, Department of Computer ScienceVibrotactile Feedback & Skin StimulationTelemedicine & Remote Patient MonitoringSleep & Stress MonitoringCHI
FlexiVol: a Volumetric Display with an Elastic Diffuser to Enable Reach-Through InteractionVolumetric displays render true 3D graphics without forcing users to wear headsets or glasses. However, the optical diffusers that volumetric displays employ are rigid and thus do not allow for direct interaction. FlexiVol employs elastic diffusers to allow users to reach inside the display volume to have direct interaction with true 3D content. We explored various diffuser materials in terms of visual and mechanical properties. We correct the distortions of the volumetric graphics projected on elastic oscillating diffusers and propose a design space for FlexiVol, enabling various gestures and actions through direct interaction techniques. A user study suggests that selection, docking and tracing tasks can be performed faster and more precisely using direct interaction when compared to indirect interaction with a 3D mouse. Finally, applications such as a virtual pet or landscape edition highlight the advantages of a volumetric display that supports direct interaction.2025EBIosune Sarasate Azcona et al.Universidad Publica de Navarra, UpnaLabHaptic WearablesShape-Changing Interfaces & Soft Robotic Materials3D Modeling & AnimationCHI
PointerVol: A Laser Pointer for Swept Volumetric DisplaysA laser pointer is a commonly used device that does not require communication with the display system or modifications on the applications, the presenter can just take a pointer and start using it. When a laser pointer is used on a volumetric display, a line rather than a point appears, making it not suitable for pointing at 3D locations. PointerVol is a modified laser pointer that allows users to point to 3D positions inside a swept volumetric display. We propose two PointerVol implementations based on timing and distance measurements, we evaluate the pointing performance using them. Finally, we present other features such as multi-user pointing, line patterns and a multi-finger wearable. PointerVol is a simple device that can help to popularize volumetric displays, or at least to make them more usable for presentations with true-3D content.2024UFUnai Javier Fernández et al.Data PhysicalizationPrototyping & User TestingUIST
Using Low-frequency Sound to Create Non-contact Sensations On and In the BodyThis paper proposes a method for generating non-contact sensations using low-frequency sound waves without requiring user instrumentation. This method leverages the fundamental acoustic response of a confined space to produce predictable pressure spatial distributions at low frequencies, called modes. These modes can be used to produce sensations either throughout the body, in localized areas of the body, or within the body. We first validate the location and strength of the modes simulated by acoustic modeling. Next, a perceptual study is conducted to show how different frequencies produce qualitatively different sensations across and within the participants' bodies. The low-frequency sound offers a new way of delivering non-contact sensations throughout the body. The results indicate a high accuracy for predicting sensations at specific body locations.2024WHWaseem Hassan et al.University of CopenhagenMid-Air Haptics (Ultrasonic)CHI
TipTrap: A Co-located Direct Manipulation Technique for Acoustically Levitated ContentAcoustic levitation has emerged as a promising approach for mid-air displays, by using multiple levitated particles as 3D voxels, cloth and thread props, or high-speed tracer particles, under the promise of creating 3D displays that users can see, hear and feel with their bare eyes, ears and hands. However, interaction with this mid-air content always occurred at a distance, since external objects in the display volume (e.g. user's hands) can disturb the acoustic fields and make the particles fall. This paper proposes TipTrap, a co-located direct manipulation technique for acoustically levitated particles. TipTrap leverages the reflection of ultrasound on the users' skin and employs a closed-loop system to create functional acoustic traps 2.1 mm below the fingertips, and addresses its 3 basic stages: selection, manipulation and deselection. We use Finite-Differences Time Domain (FDTD) simulations to explain the principles enabling TipTrap, and explore how finger reflections and user strategies influence the quality of the traps (e.g. approaching direction, orientation and tracking errors), and use these results to design our technique. We then implement the technique, characterizing its performance with a robotic hand setup and finish with an exploration of the ability of TipTrap to manipulate different types of levitated content.2022EJEimontas Jankauskis et al.Mid-Air Haptics (Ultrasonic)Force Feedback & Pseudo-Haptic WeightUIST
LeviProps: Animating Levitated Optimized Fabric Structures using Holographic Acoustic Tweezers LeviProps are tangible structures used to create interactive mid-air experiences. They are composed of an acoustically-transparent lightweight piece of fabric and attached beads that act as levitated anchors. This combination enables real-time 6 Degrees-of-Freedom control of levitated structures which are larger and more diverse than those possible with previous acoustic approaches. LeviProps can be used as free-form interactive elements and also as projection surfaces. We developed an authoring tool to support the creation of LeviProps. Our tool employs the outline of the prop and the user constraints to compute the optimum locations for the anchors (i.e. maximizing trapping forces), increasing prop stability and maximum size. The tool produces a final LeviProp design which can be fabricated following a simple procedure. This paper evaluates our approach and showcases example applications such as interactive storytelling, games and mid-air displays.2019RGRafael Morales González et al.Mid-Air Haptics (Ultrasonic)Shape-Changing Interfaces & Soft Robotic MaterialsDigital Art Installations & Interactive PerformanceUIST