Search Results (8)

Developing a multimodal tactile display is a key area of interest for haptic scientists, with researchers continuously exploring new methods to achieve this goal. This study introduces a tactile–olfactory display capable of providing touch, temperature, and odor feedback. The display utilizes airflow to deliver feedback to the user, incorporating two air sources and thermoelectric components (Peltier elements). Unlike traditional technologies, it employs convection-based temperature stimulation, where air passing over the thermoelectric modules cools or warms, resulting in temperature modulation. The system was tested under steady airflow conditions (DC airflow) and frequency-modulated airflow conditions (AC airflow). First, a finite element simulation was conducted in Ansys to gain insights into the system parameters. This was followed by experimental evaluations to extract its characteristics and assess its performance. The results indicate that not only the type of airflow but also its rate and frequency play significant roles in rendering surface parameters. Additionally, this airflow-based tactile display has potential applications in both contact and noncontact haptic technologies. Full article

Reliable detection of contact states, such as the “mating” of connectors, is crucial for high-quality teleoperated assembly. Conventional systems relying solely on visual and continuous force feedback often fail to convey these discrete high-frequency transients due to the limited high-frequency rendering capabilities. This study investigates the effectiveness of augmenting visual and force feedback with vibrotactile and auditory cues for detecting connector mating. We conducted three experiments: (1) a mating detection task using recorded multimodal data ($N=10$), (2) a modality contribution analysis ($N=10$), and (3) a real-time robot connector insertion task ($N=10$). Results from the real-time task demonstrated that the proposed multimodal feedback significantly reduced the maximum contact force exerted after mating compared to the baseline visual-force condition ($p<0.001$), thereby enhancing physical safety. Furthermore, vibrotactile and auditory cues were found to be redundant yet complementary, providing robust cues even when one modality is compromised. Although subjective mental workload increased due to sensory integration, the significant improvement in detection clarity and safety justifies the multimodal approach. We conclude that providing transient vibrotactile and auditory cues is a highly effective strategy for compensating for the limitations of conventional force feedback in teleoperated assembly. Full article

Surface texture displays are touch panels that provide tactile feedback. Presenting softness sensations on such rigid surfaces remains a challenge, and effective methods are not yet established. This study explores how low-frequency frictional modulation during finger sliding can evoke the perception of softness. We examined multimodal optimization—whether the optimal tactile parameters vary depending on the type of visually presented fabric. Videos of draping cloth were shown beneath the panel, while spatial wavelength of frictional modulation and finger sliding speed were optimized using response surface methodology. The optimal spatial wavelength did not significantly differ across fabric types: towel (16.8 mm), cotton (16.5 mm), leather (17.1 mm), and suede (15.4 mm), with an overall range of 15–18 mm. In contrast, the optimal sliding speed significantly varied by fabric: towel (144 mm/s), cotton (118 mm/s), leather (167 mm/s), and suede (96 mm/s). These results suggest that frictional variation with a fixed spatial wavelength may serve as a general strategy for presenting softness. The findings contribute to advancing tactile rendering techniques for hard touch surfaces. Full article

Humans mostly perceive tactile sensations in daily life as a combination of warmth, vibration, and pressure. To understand the complex tactile perception and cognitive processes, in this study, we aimed to develop a multimodal stimulator and investigate changes in neuronal activity. An actuator that can display warmth (W), vibration (V), and pressure (P) on the distal region of the index finger has been developed. Preliminary experiments were conducted with nine subjects. Electroencephalograms were measured for six tactile stimuli—three single stimuli (W, V, and P) and three combination stimuli (W + V, V + P, and W + V + P)—and event-related desynchronization/synchronization (ERD/S) analysis were performed. The actuator can present all kinds of stimuli in the same location and control stimulation parameters quantitatively. For all experiments, there was an ERD in the α and β bands about 0.5 s after stimulation followed by ERS was observed in the C3 area. The change in the peak-to-peak value was the largest for warmth and the smallest for pressure. In contrast, in the duration of the ERD, W was the shortest and P was the longest. As stimulus presented simultaneously, the ERD became longer in both the alpha and beta bands. In the beta band, the peak of ERD became larger. The developed system was confirmed to be capable of providing valid tactile stimulation, inducing appropriate neuronal activation, and enabling multimodal tactile research. Full article

Over the last decade, several projects have demonstrated how interactive tactile graphics and tangible interfaces can improve and enrich access to information for people with vision impairments. While the former can be used to display a relatively large amount of information, they cannot be physically updated, which constrains the type of tasks that they can support. On the other hand, tangible interfaces are particularly suited for the (re)construction and manipulation of graphics, but the use of physical objects also restricts the type and amount of information that they can convey. We propose to bridge the gap between these two approaches by investigating the potential of tactile and tangible graphics for people with vision impairments. Working closely with special education teachers, we designed and developed the FlexiBoard, an affordable and portable system that enhances traditional tactile graphics with tangible interaction. In this paper, we report on the successive design steps that enabled us to identify and consider technical and design requirements. We thereafter explore two domains of application for the FlexiBoard: education and board games. Firstly, we report on one brainstorming session that we organized with four teachers in order to explore the application space of tangible and tactile graphics for educational activities. Secondly, we describe how the FlexiBoard enabled the successful adaptation of one visual board game into a multimodal accessible game that supports collaboration between sighted, low-vision and blind players. Full article

During open surgery, a surgeon relies not only on the detailed view of the organ being operated upon and on being able to feel the fine details of this organ but also heavily relies on the combination of these two senses. In laparoscopic surgery, haptic feedback provides surgeons information on interaction forces between instrument and tissue. There have been many studies to mimic the haptic feedback in laparoscopic-related telerobotics studies to date. However, cutaneous feedback is mostly restricted or limited in haptic feedback-based minimally invasive studies. We argue that fine-grained information is needed in laparoscopic surgeries to study the details of the instrument’s end and can convey via cutaneous feedback. We propose an exoskeleton haptic hand wearable which consists of five 4 × 4 miniaturized fingertip actuators, 80 in total, to convey cutaneous feedback. The wearable is described as modular, lightweight, Bluetooth, and WiFi-enabled, and has a maximum power consumption of 830 mW. Software is developed to demonstrate rapid tactile actuation of edges; this allows the user to feel the contours in cutaneous feedback. Moreover, to demonstrate the idea as an object displayed on a flat monitor, initial tests were carried out in 2D. In the second phase, the wearable exoskeleton glove is then further developed to feel 3D virtual objects by using a virtual reality (VR) headset demonstrated by a VR environment. Two-dimensional and 3D objects were tested by our novel untethered haptic hand wearable. Our results show that untethered humans understand actuation in cutaneous feedback just in a single tapping with 92.22% accuracy. Our wearable has an average latency of 46.5 ms, which is much less than the 600 ms tolerable delay acceptable by a surgeon in teleoperation. Therefore, we suggest our untethered hand wearable to enhance multimodal perception in minimally invasive surgeries to naturally feel the immediate environments of the instruments. Full article

Visually impaired people can take advantage of multimodal systems in which visual information is communicated through different modes of interaction and types of feedback. Among the possible interaction modes, thermal interaction in the context of assistive devices for visually impaired people lacks research in spite of its potential. In this paper, we propose a temperature-depth mapping algorithm and a thermal display system to convey depth and depth-color of artworks’ features in the context of tactile exploration by visually impaired people. Tests with a total of 18 sighted users and six visually impaired users were performed both during the mapping algorithm design and after developing a tactile temperature prototype artwork model to assess the potentials of thermal interaction for recognizing depth and color-depth in tactile art appreciation. These tests showed both an existing correlation between depth and temperature and that the mapping based on that correlation is appropriate for conveying depth during artwork tactile exploration. Full article

Using a multisensory interface system, we examined how people’s emotional experiences change as their tactile sense (touching a plant) was augmented with visual sense (“seeing” their touch). Our system (the Interactive Plant system) senses the electrical capacitance of the human body and visualizes users’ tactile information on a flat screen (when the touch is gentle, the program draws small and thin roots around the pot; when the touch is more harsh or abrupt, big and thick roots are displayed). We contrasted this multimodal combination (touch + vision) with a unimodal interface (touch only or watch only) and measured the impact of the multimodal interaction on participants’ emotion. We found significant emotional gains in the multimodal interaction. Participants’ self-reported positive affect, joviality, attentiveness and self-assurance increased dramatically in multimodal interaction relative to unimodal interaction; participants’ electrodermal activity (EDA) increased in the multimodal condition, suggesting that our plant-based multisensory visual-tactile interaction raised arousal. We suggest that plant-based tactile interfaces are advantageous for emotion generation because haptic perception is by nature embodied and emotional. Full article