Haptic Interaction Research Articles

Tactile Sensitivity to Missing tones in Complex Vibrotactile Signals.

Haptic interactions with objects induce complex vibrotactile signals that are central to tactile perception. Despite the broad literature on vibrotactile perception, surprisingly little is known about the sensory processing of complex tactile signals made of multiple pure tones. To fill this gap, the study reported here investigated the impact of the constitutive pure tones of a complex vibrotactile signal on its perception. Participants completed a 3-AFC task, in which they were asked to identify an odd signal among two complex references. The odd signal was created by removing one pure tone from the reference, which varied in spectral composition, harmonicity, and inter-frequency intervals. Each reference signal was made of either two, three, or four pure tones. The results revealed that the removed pure tone's value as well as the inter-frequency interval play a significant role on participants' performance whereas changes in harmonicity and complexity have little impact. The smaller the ratio between the removed frequency and the lowest one of the reference signals, the better the participants' capacity to identify the signal with the missing tone. As this ratio correlates with that of pure tone's perceived intensity, participants' performance can be linked to either of them. Analysis of a subset of complex signals made of pure tones perceived with roughly equal intensity showed that the correlation still holds but slightly decreases. Overall, these results suggest that perception of complex vibrations might be mediated by tactile mechanisms related to both frequency selectivity and to pure tones perceived intensity.

Somatic Stimulation and the Grail: Experiencing London British Library Royal MS 14.E.III as a Haptic Interface

ABSTRACT Michael Camille (2000, 216) suggests that medieval images are “not the reflection of some external view of this world but the beginning and foundation of a process of thought.” This article suggests that the audience to London British Library Royal MS 14.E.iii used haptic interaction with the codex as a way of uniting physical and spiritual sensory perception. In this way, the manuscript’s audience utilized a process that we might today define as “embodied reading,” in which the reception of a given narrative is enhanced through the stimulation of multiple sensory modalities. Building upon new work by Kathryn Rudy that focuses on the damage caused by touching, rubbing, and kissing religious manuscripts, I argue that the same “damage-by-loving-touch” can also be seen in two miniatures in Royal 14.E.iii. In each example, the audience’s targeted touching of the Grail table mirrors the way in which characters within the text touch (and are subsequently healed by) the same object. By extension, this suggests that the lessons (and potential benefits) of accessing the Grail were understood to be applicable to the manuscript’s audience: the owners of Royal 14.E.iii treated the manuscript as if it was a devotional text, physical contact with which allowed them to participate in the events of the narrative.

Alterable Robotic Skin Using Material Gene Expression Modulation

AbstractRobotic skins that integrate artificial tactile sensing elements can substantially complement the perception dimension of social robots, presenting an indispensable part in human‐robot interaction (HRI). However, existing design frameworks compromise between versatility and sustainability due to the restricted range of characteristics available for a single constituent. Here an alterable robotic skin constructed from homogeneous sensing units are proposed, capable of cyclically realtering their inherent characteristics across a wide spectrum. Necessary characteristics to achieve positioning and pressure sensing subunits can be encoded in the feature motifs and extracted through condition‐induced differentiation, showcasing a remarkable resemblance to the gene expression in the living system. By virtue of this, up to 100‐fold differences in feature parameters are achieved, including modulus, surface state, and conductivity, to drive the target attribute coupling. The trans‐temporal reconstruction of materials enables the superb customization of functional building blocks, advancing the flexible separation and combination of different touch modes, including location, pressure, duration, and motion pattern. As a proof of concept, the alterable robotic skin is demonstrated that integrates a position‐sensing layer and a pressure‐sensing layer. It can accurately distinguish and recognize multi‐dimensional touch motions based on less‐channel data, which showcases an efficient haptic interaction application.

Investigations of motor performance with neuromodulation and exoskeleton using leader-follower modality: a tDCS study.

This study investigates how the combination of robot-mediated haptic interaction and cerebellar neuromodulation can improve task performance and promote motor skill development in healthy individuals using a robotic exoskeleton worn on the index finger. The authors propose a leader-follower type of mirror game where participants can follow a leader in a two-dimensional virtual reality environment while the exoskeleton tracks the index finger motion using an admittance filter. The game requires two primary learning phases: the initial phase focuses on mastering the pinching interface, while the second phase centers on predicting the leader's movements. Cerebral transcranial direct current stimulation (tDCS) with anodal polarity is applied to the subjects during the game. It is shown that the subjects' performance improves as they play the game. The combination of tDCS with finger exoskeleton significantly enhances task performance. Our research indicates that modulation of the cerebellum during the mirror game improves the motor skills of healthy individuals. The results also indicate potential uses for motor neurorehabilitation in hemiplegia patients.

Haptic touch modulates size adaptation aftereffects on the hand.

When we interact with objects using our hands, we derive their size through our skin. Prolonged exposure to an object leads to a perceptual size aftereffect: adapting to a larger/smaller object makes a subsequently perceived object to appear smaller/larger than its actual size. This phenomenon has been described as haptic as tactile sensations with kinesthetic feedback are involved. However, the exact role of different haptic components in generating this aftereffect remains largely underexplored. Here, we investigated how different aspects of haptic touch influence size perception. After adaptation to a large sphere with one hand and a small sphere with the other, participants touched two test spheres of equal or different sizes and judged which one felt larger. Similar haptic size adaption aftereffects were observed (a) when participants repeatedly grasped on and off the adapters, (b) when they simply continued to grasp the adapters without further hand movements, and (c) when the adapters were grasped without involving the fingers. All these conditions produced stronger aftereffects than a condition where the palms were simply resting on the adapter. Our findings suggest that the inclusion of grasp markedly increased the aftereffects, highlighting the pivotal role of haptic interactions in determining perceptual size adaptation. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Evaluation of Haptic Textures for Tangible Interfaces for the Tactile Internet

Every texture in the real world provides us with the essential information to identify the physical characteristics of real objects. In addition to sight, humans use the sense of touch to explore their environment. Through haptic interaction we obtain unique and distinct information about the texture and the shape of objects. In this paper, we enhance X3D 3D graphics files with haptic features to create 3D objects with haptic feedback. We propose haptic attributes such as static and dynamic friction, stiffness, and maximum altitude that provide the optimal user experience in a virtual haptic environment. After numerous optimization attempts on the haptic textures, we propose various haptic geometrical textures for creating a virtual 3D haptic environment for the tactile Internet. These tangible geometrical textures can be attached to any geometric shape, enhancing the haptic sense. We conducted a study of user interaction with a virtual environment consisting of 3D objects enhanced with haptic textures to evaluate performance and user experience. The goal is to evaluate the realism and recognition accuracy of each generated texture. The findings of the study aid visually impaired individuals to better understand their physical environment, using haptic devices in conjunction with the enhanced haptic textures.

Evaluating Force-based Haptics for Immersive Tangible Interactions with Surface Visualizations.

Haptic feedback provides an essential sensory stimulus crucial for interaction and analyzing three-dimensional spatio-temporal phenomena on surface visualizations. Given its ability to provide enhanced spatial perception and scene maneuverability, virtual reality (VR) catalyzes haptic interactions on surface visualizations. Various interaction modes, encompassing both mid-air and on-surface interactions-with or without the application of assisting force stimuli-have been explored using haptic force feedback devices. In this paper, we evaluate the use of on-surface and assisted on-surface haptic modes of interaction compared to a no-haptic interaction mode. A force-based haptic stylus is used for all three modalities; the on-surface mode uses collision based forces, whereas the assisted on-surface mode is accompanied by an additional snapping force. We conducted a within-subjects user study involving fundamental interaction tasks performed on surface visualizations. Keeping a consistent visual design across all three modes, our study incorporates tasks that require the localization of the highest, lowest, and random points on surfaces; and tasks that focus on brushing curves on surfaces with varying complexity and occlusion levels. Our findings show that participants took almost the same time to brush curves using all the interaction modes. They could draw smoother curves using the on-surface interaction modes compared to the no-haptic mode. However, the assisted on-surface mode provided better accuracy than the on-surface mode. The on-surface mode was slower in point localization, but the accuracy depended on the visual cues and occlusions associated with the tasks. Finally, we discuss participant feedback on using haptic force feedback as a tangible input modality and share takeaways to aid the design of haptics-based tangible interactions for surface visualizations.

A tactile oral pad based on carbon nanotubes for multimodal haptic interaction

A tactile oral pad based on carbon nanotubes for multimodal haptic interaction

A comprehensive study to learn the impact of augmented reality and haptic interaction in ultrasound-guided percutaneous liver biopsy training and education

Simulation based training methods are gaining popularity as they could provide a platform for practitioners to gain hands-on experience without causing ethical issues. By combining augmented reality (AR) and haptics, a training method for percutaneous liver biopsy (PLB) could be developed providing realistic scenarios, and real-time visualization of the human anatomy and needle. Additionally, it could also provide real-time feedback to the practitioner. In this review, we describe the conventional PLB procedure, then discuss AR technology and its application in the field of medicine for image-guided therapies, especially, hepatic biopsy. Next, we summarize the associated devices, models and methods illustrating a few haptic simulators devised for training and gesture assessment. Lastly, we present a few potential approaches to integrate AR and haptic interaction to develop a PLB training simulator by accounting the existing challenges.

Multisensory Extended Reality Applications Offer Benefits for Volumetric Biomedical Image Analysis in Research and Medicine.

3D data from high-resolution volumetric imaging is a central resource for diagnosis and treatment in modern medicine. While the fast development of AI enhances imaging and analysis, commonly used visualization methods lag far behind. Recent research used extended reality (XR) for perceiving 3D images with visual depth perception and touch but used restrictive haptic devices. While unrestricted touch benefits volumetric data examination, implementing natural haptic interaction with XR is challenging. The research question is whether a multisensory XR application with intuitive haptic interaction adds value and should be pursued. In a study, 24 experts for biomedical images in research and medicine explored 3D medical shapes with 3 applications: a multisensory virtual reality (VR) prototype using haptic gloves, a simple VR prototype using controllers, and a standard PC application. Results of standardized questionnaires showed no significant differences between all application types regarding usability and no significant difference between both VR applications regarding presence. Participants agreed to statements that VR visualizations provide better depth information, using the hands instead of controllers simplifies data exploration, the multisensory VR prototype allows intuitive data exploration, and it is beneficial over traditional data examination methods. While most participants mentioned manual interaction as the best aspect, they also found it the most improvable. We conclude that a multisensory XR application with improved manual interaction adds value for volumetric biomedical data examination. We will proceed with our open-source research project ISH3DE(Intuitive Stereoptic Haptic 3D Data Exploration) to serve medical education, therapeutic decisions, surgery preparations, or research data analysis.

Towards Better Utilization of Haptic Interaction in Visualization: Design Space and Knob Prototype

Humans encounter a vast array of sensory stimuli in their everyday lives. However, many visualization techniques primarily utilize visual feedback, which may disregard certain intricate details. Relying on a single visual channel may overlook complex layouts. However, how haptic force feedback can be used to assist visualization remained under-explored. In this work, we initially conducted a literature review to identify potential problems in the visualization of large datasets and engaged in discussions with domain experts to explore the potential of haptic force feedback and visual collision representation. Subsequently, we designed an innovative haptic force feedback knob, which included 3 primary modules and 29 elements. To evaluate the clarity and usefulness of this design space, we conducted a workshop and devised “recommended solutions” for the identified visualization problems. Finally, we implemented a prototype of the haptic force feedback knob and assessed its performance on scatterplot and parallel coordinate plot tasks using large datasets. The results indicated that the knob prototype could reduce visual strain and enhance the efficiency of visualization tasks.

Multiscale Textile‐Based Haptic Interactions

Wearable haptic devices transmit information via touch receptors in the skin, yet devices located on parts of the body with high densities of receptors, such as fingertips and hands, impede interactions. Other locations that are well‐suited for wearables, such as the wrists and arms, suffer from lower perceptual sensitivity. The emergence of textile‐based wearable devices introduces new techniques of fabrication that can be leveraged to address these constraints and enable new modes of haptic interactions. This article formalizes the concept of “multiscale” interaction, an untapped paradigm for haptic wearables, enabling enhanced delivery of information via textile‐based haptic modules. In this approach, users choose the depth and detail of their haptic experiences by varying their interaction mode. Flexible prototyping methods enable multiscale haptic bands that provide both body‐scale interactions (on the forearm) and hand‐scale interactions (on the fingers and palm). A series of experiments assess participants’ ability to identify pressure states and spatial locations delivered by these bands across these interaction scales. A final experiment demonstrates the encoding of three‐bit information into prototypical multiscale interactions, showcasing the paradigm's efficacy. This research lays the groundwork for versatile haptic communication and wearable design, offering users the ability to select interaction modes for receiving information.

A Cable-Based Haptic Interface with a Reconfigurable Structure

Abstract Cable robots have been used as haptic interfaces for several decades now, with the most notable examples being the SPIDAR and its numerous iterations throughout the years, as well as the more recent IPAnema 3 Mini manufactured by Fraunhofer IPA. However, these robots still have drawbacks, particularly their high number of cables required to maintain a high workspace-to-installation-space ratio. Using a hybrid-structure cable robot (HSCR) could prevent some collisions that occur between the cables and the user's body. More specifically, some applications requiring multimodal feedback could benefit from the flexibility that a reduced number of cables offers. Therefore, this paper presents a novel SPIDAR-like VSCR and its sensor-less force control method based on motor current. The purpose of this work is to clarify the advantages that a variable structure can provide for haptic interaction. In this regard, experimental results regarding the device's workspace and its force feedback capabilities are presented. Additionally, since real-time high-frequency updates are required for haptic display, we provide additional data regarding the control algorithm's runtime. Lastly, another experiment was conducted to study changes in user performance when using both the variable and the usual cable configuration. The results showed that feedback accuracy is maintained, and there are no drawbacks to using hybrid configurations.

“Moving with the story”: the haptics of reader experience and response to digital comics

ABSTRACT The experience of reading digital comics differs from that of other reading in that it involves the interplay between text and art, both “on the page”, for example, as with the traditional comic book format, or “off the page” in interaction with devices, apps and “extras” the Alt Text in the webcomic, xkcd. This interplay and placement can communicate movement, stillness, suspense, bringing the reader along not only through content or story arc but also through the material affordances, the physical reality of the comic in combination with the technology. The findings of this exploratory study reveal both the varied reading experiences of digital comics as well as the shared experiences of haptic interactions and emotional perception and reaction through the use of devices, comics platforms and apps, and social media. Although webcomics, one type of digital comics, have long been a part of the evolution of hypertext, their place has not always been acknowledged in the scholarship. This research not only contributes towards an empirical, qualitative understanding of reader response to and experience of a range of digital comics including webcomics, but also addresses their role as an example of the haptics of hypertext fiction.

Haptic Magnetism.

New interactions are often developed by mimicking the real world. Therefore, many researchers in haptics have focused on creating a realistic experience of contact between users and objects. However, dispensing with mimicry may allow us to develop novel haptic interactions. We present Haptic Magnetism, an interaction modality that delivers sensations of distant objects through tactile stimulation and enables interactions through pseudo-magnetic attraction and repulsion. To show the feasibility of Haptic Magnetism, we designed 12 pseudo-magnetic stimuli and assessed them in two studies. In the first study, we show that participants gain a sense of distant objects. In the second study, we evaluate a subset of stimuli to show that participants can interact with the objects based on experiences of pseudo-magnetic attraction and repulsion. Finally, we discuss how Haptic Magnetism supports guiding movements, nudging users, and revealing affordances.

Multimodal 5‐DOF Stretchable Electromagnetic Actuators toward Haptic Information Delivery

AbstractThe rapid advancements in artificial intelligence, particularly in the domains of robotics, prosthetics, and virtual and augmented reality (VR/AR), have driven an escalating demand for intuitive and effective human–machine interactions. Consequently, haptic devices, being electronic displays for the sense of touch, have drawn increasing attention. More efforts are in demand to develop stretchable and lightweight haptic devices that can trigger multiple mechanical cutaneous receptors using a single device. This work presents a new 3‐modal 5‐DOF stretchable haptic interface that is enabled by electromagnetic actuators and high‐fidelity multi‐layer metal printing. The haptic device renders rich haptic sensations (i.e., normal force, vibration, angular force, skin dragging) in one device, allowing for the comprehensive delivery of tactile information through the excitation of multiple cutaneous receptors. Additionally, haptic devices are designed to be compact, lightweight, and skin‐compatible. The skin‐like softness and stretchability enable intimate skin contact, which is crucial for efficient haptic information delivery. This feature prevents the impediment to natural movements of the skin and ensures the functional integrity of the device during daily deformations of the skin. Finally, three proof‐of‐concept demonstrations illustrate the potential of the reported multimodal haptic devices for advanced haptic interactions across various domains.

A Spatially Selective Electroactive‐Actuating Adhesive Electronics for Multi‐Object Manipulation and Adaptive Haptic Interaction (Adv. Funct. Mater. 6/2024)

A Spatially Selective Electroactive‐Actuating Adhesive Electronics for Multi‐Object Manipulation and Adaptive Haptic Interaction (Adv. Funct. Mater. 6/2024)

Haptic Sensing and Feedback Techniques toward Virtual Reality.

Haptic interactions between human and machines are essential for information acquisition and object manipulation. In virtual reality (VR) system, the haptic sensing device can gather information to construct virtual elements, while the haptic feedback part can transfer feedbacks to human with virtual tactile sensation. Therefore, exploring high-performance haptic sensing and feedback interface imparts closed-loop haptic interaction to VR system. This review summarizes state-of-the-art VR-related haptic sensing and feedback techniques based on the hardware parts. For the haptic sensor, we focus on mechanism scope (piezoresistive, capacitive, piezoelectric, and triboelectric) and introduce force sensor, gesture translation, and touch identification in the functional view. In terms of the haptic feedbacks, methodologies including mechanical, electrical, and elastic actuators are surveyed. In addition, the interactive application of virtual control, immersive entertainment, and medical rehabilitation is also summarized. The challenges of virtual haptic interactions are given including the accuracy, durability, and technical conflicts of the sensing devices, bottlenecks of various feedbacks, as well as the closed-loop interaction system. Besides, the prospects are outlined in artificial intelligence of things, wise information technology of medicine, and multimedia VR areas.

Relaxing Conservatism for Enhanced Impedance Range and Transparency in Haptic Interaction.

The Time Domain Passivity Approach (TDPA) has been accepted as one of least conservative tools for designing stabilizing controllers in haptics and teleoperation, but it still suffers from conservatism because it is based on passivity. Additionally, high-frequency, immediate control actions lead to a degradation of transparency. In this paper, we propose a method to relax the conservatism of haptic interaction and enhance stable impedance range while maintaining high transparency. Based on the observation of energy exchange behavior in pressing and releasing paths in haptic interaction, we introduce an energy cycle as a completion of a pressing and releasing path. With this new concept, we compare the energies at the end of each energy cycle to estimate the energy generation and inject adaptive damping to regulate it over upcoming cycles. Because we wait a pressing-releasing cycle is completed, we allow energy to be generated, but we regulate the amount of generated energy over upcoming cycles by injecting adaptive damping. In this way, we perform low-frequency control actions on system dynamics. These in turn enable us to achieve high transparency. We show the validity of the proposed approach through several simulations and experiments, and show that it enhances the stable impedance range and transparency compared to the TDPA.

Motor Learning in Robot-Based Haptic Dyads: A Review.

Rehabilitation robots have the potential to alleviate the global burden of neurorehabilitation. Robot-based multiplayer gaming with virtual and haptic interaction may improve motivation, engagement, and implicit learning in robotic therapy. Over the past few years, there has been growing interest in robot mediated haptic dyads, or human-robot-robot-human interaction. The effect of such a paradigm on motor learning in general and specifically for individuals with motor and/or cognitive impairments is an open area of research. We reviewed the literature to investigate the effect of a robot-based haptic dyad on motor learning. Thirty-eight articles met the inclusion criteria for this review. We summarize study characteristics including device, haptic rendering, and experimental task. Our main findings indicate that dyadic training's impact on motor learning is inconsistent in that some studies show significant improvement of motor training while others show no influence. We also find that the relative skill level of the partner and interaction characteristics such as stiffness of connection and availability of visual information influence motor learning outcomes. We discuss implications for neurorehabilitation and conclude that additional research is needed to determine optimal interaction characteristics for motor learning and to extend this research to individuals with cognitive and motor impairments.