Haptic Research Research Articles

Pedagogical tact at the intersection: optimizing educational practice amid intercultural and digital transformations

ABSTRACT This paper examines the challenge of mediating theory and practice in pedagogy, specifically focusing on the critical importance of educational tact as a mediator between the two. It first defines the role of pedagogical tact, underlining its significance as a vital skill for professionals. It also explores the qualities of teachers who embrace diversity and foster intercultural understanding, which is essential and crucial in our increasingly globalized world. Moreover, it underscores the unique role of pedagogical tact in haptic research, a field of growing significance in the digital age. Haptic research involving the sense of touch is pivotal in advancing digital technologies such as artificial intelligence. The paper concludes that modernizing pedagogical tact can forge a comprehensive learning environment that addresses the needs of the times.

Real human touch: performer-facilitated touch enhances presence and embodiment in immersive performance

Despite being an embodied medium, virtual reality (VR) prioritizes vision and sound over the other senses. While touch has been demonstrated to foster a sense of presence and embodiment, most haptic research in VR focuses on uncanny vibration motors or limited experiences of touch with simple props. Meanwhile, immersive performances such as Eve 3.0 incorporate performer-facilitated touch in novel ways to evoke a complete and social experience of human touch in VR. In response, we conducted a mixed-methods study to investigate the experience of performer-facilitated touch in a 360° video segment from the immersive performance Eve 3.0. Using a 3 × 2 factorial design, we compared touch from a diary prop and performer in festival and laboratory settings. We found that performer-facilitated touch increased realistic behaviours and questionnaire measures of social presence, embodiment, and tactile realism. The setting also had a significant effect with festival participants demonstrating significantly more behaviours indicating presence, particularly in the no-touch condition. Participant descriptions reveal that in addition to touch, a rich narrative and vivid visuals of social interaction were just as important in immersing participants in the experience and making them feel present. We find that participant experiences are a co-creation situated at the intersection of artefact and context that require a willing suspension of disbelief. The authentic setting and performance artefact afforded a deep understanding of the rich and complex experience of human touch in immersive performance.

Haptic device and interface to reproduce force and tactile feedback of biological tissues

Haptic information of biological tissues is important in applications and research in medical fields, including force and tactile feedback. Due to resource limitation, various biological tissues may not be easily accessible, so as to hinder their haptic research and development. Therefore, in this paper, force and tactile feedback of five pig tissue samples are respectively reproduced by using a combination of haptic device and interface. Specifically, the haptic device is used to reproduce the force-displacement relationship, while the haptic interface is used to provide various and controllable touch sensations to human fingers. First, the force-displacement relationships of five pig tissue samples are derived via compression tests. Second, the haptic device with two springs and a customized raceway is designed, modeled, and fabricated. Third, compression tests are performed on the haptic device to verify its reproduction accuracy. Later, the pneumatic haptic interface is designed and fabricated. Last, the haptic device and interface are combined and tested. The proposed haptic device and interface can provide accurate force feedback as well as various and controllable tactile feedback to human fingers.

On the Correlation Between Tactile Stimulation and Pleasantness.

Several studies in the affective haptics research field showed the potential of using haptic technology to convey emotions in remote communications. In this context, it is of interest to simplify the haptic feedback without altering the informative content of the stimulus, with a two-fold advantage. On one side, it would allow the development of affective haptic devices whose technological complexity is limited, hence more compatible with wearability and portability requirements. On the other side, having a simplified set of stimuli would decrease the amount of data to be transmitted, thus improving the overall quality of remote haptic interactions. In this work, we investigated the correlation between the parameters regulating a caress-like stimulation and the perceived pleasantness. This was done by means of two experiments, in which we asked subjects to adjust the temperature and the motion velocity of a set of stimuli in order to find the most pleasant combination. Results indicated that subjects preferred different values of temperature and velocity of the stimulus depending on the proposed tactile stimulation. A small difference in the pleasantness ratings was observed between caresses provided with linear movements and those given as discrete sequences of taps. In particular, participants preferred linear movements set at 34.5 °C and 3.4 cms-1. As regards caress-like stimuli provided with discrete sequences of taps, the preferred temperature and velocity were 33.2 °C and 2.9 cms-1, respectively. The presence of vibration had a little effect on the perceived pleasantness.

Cognitive and Physical Activities Impair Perception of Smartphone Vibrations.

Vibration feedback is common in everyday devices, from virtual reality systems to smartphones. However, cognitive and physical activities may impede our ability to sense vibrations from devices. In this study, we develop and characterize a smartphone platform to investigate how a shape-memory task (cognitive activity) and walking (physical activity) impair human perception of smartphone vibrations. We measured how Apple's Core Haptics Framework parameters can be used for haptics research, namely how hapticIntensity modulates amplitudes of 230 Hz vibrations. A 23-person user study found that physical ( ) and cognitive ( p=0.012) activity increase vibration perception thresholds. Cognitive activity also increases vibration response time ( ). This work also introduces a smartphone platform that can be used for out-of-lab vibration perception testing. Researchers can use our smartphone platform and results to design better haptic devices for diverse, unique populations.

Perceptual Space of Algorithms for Three-to-One Dimensional Reduction of Realistic Vibrations.

Haptics researchers often endeavor to deliver realistic vibrotactile feedback through broad-bandwidth actuators; however, these actuators typically generate only single-axis vibrations, not 3D vibrations like those that occur in natural tool-mediated interactions. Several three-to-one (321) dimensional reduction algorithms have thus been developed to combine 3D vibrations into 1D vibrations. Surprisingly, the perceptual quality of 321-converted vibrations has never been comprehensively compared to rendering of the original 3D signals. In this study, we develop a multi-dimensional vibration rendering system using a magnetic levitation haptic interface. We verify the system's ability to generate realistic 3D vibrations recorded in both tapping and dragging interactions with four surfaces. We then conduct a study with 15 participants to measure the perceived dissimilarities between five 321 algorithms (SAZ, SUM, VM, DFT, PCA) and the original recordings. The resulting perceptual space is investigated with multiple regression and Procrustes analysis to unveil the relationship between the physical and perceptual properties of 321-converted vibrations. Surprisingly, we found that participants perceptually discriminated the original 3D vibrations from all tested 1D versions. Overall, our results indicate that spectral, temporal, and directional attributes may all contribute to the perceived similarities of vibration signals.

Task and Material Properties Interactively Affect Softness Explorations Along Different Dimensions.

Haptic research has frequently equated softness with the compliance of elastic objects. However, in a recent study we have suggested that compliance is not the only perceived material dimension underlying what is commonly called softness [1 ]. Here, we investigate, whether the different perceptual dimensions of softness affect how materials are haptically explored. Specifically, we tested whether also the task, i.e., the attribute that a material is being judged on, might affect how a material is explored. To this end we selected 15 adjectives and 19 materials that each associate with different softness dimensions for the study. In the experiment, while participants freely explored and rated the materials, we recorded their hand movements. These movements were subsequently categorized into distinct exploratory procedures (EPs) and analyzed in a multivariate analysis of variance (MANOVA). The results of this analysis suggest that the pattern of EPs depended not only on the material's softness dimension and the task (i.e., what attributes were rated), but also on an interaction between the two factors. Taken together, our findings support the notion of multiple perceptual dimensions of softness and suggest that participants actively adapt their EPs in a nuanced way when judging a particular softness dimensions for a given material.

Stability Analysis and User Perception of Haptic Rendering Combining Virtual Elastic, Viscous and Inertial Effects

Virtual Reality environments are being used on a mass scale in fields, such as Industry and Medicine. These virtual scenarios serve very different purposes such as prototyping, gaming and exercising. Interaction with the virtual environment is mainly achieved by senses of sight and hearing through devices, such as a mouse or VR glasses. To this end, haptic research started a few decades ago with the aim of improving this interaction through a sense of touch. A key element, hitherto not researched, is the effective combination of virtual elastic, viscous, and inertial effects in haptic feedback restored to the user and the safety implications of these feedback effects. It is of particular importance in neurological rehabilitation exercising, as interaction realism and safety are of great importance in therapy and for the patient. Therefore, this work addresses the stability analysis of the combination of three haptic effects—elastic, viscous, and inertial—and the subjective feeling on the part of users regarding different combinations of these effects. A theoretical analysis is presented with a view to establishing stable control principles, and a user-study was carried out in order to help understand the perception of users to different combinations of haptic effects.

Influence of Sparse Contact Point and Finger Penetration in Object on Shape Recognition.

Making a virtual object shape recognizable using a haptic display is one of the major themes of haptic research. In previous works, multipoint haptic displays have been developed that had a high contact point density between the users' finger skin and the virtual object. However, the ideal contact point density that enables intuitive shape recognition has not been determined yet. Meanwhile, there is also a fundamental problem; that is, real fingers and virtual objects do penetrate, which cannot be solved with such wearable displays. This article investigated the influence of both contact point density and penetration on the shape recognition performance. We prepared a real testing environment where the user touched the real object, and where we could simulate both the sparse contact point and the penetration. Specifically, users' fingers wore thin film coated with glass particles and they touched the urethane foams that deformed flexibly. The result of experiments showed a broad trend where the sparseness of the contact and the softness of the object influenced the exploration time required to achieve recognition. In addition, the result suggested that the larger contact density could make up for the problem of penetration. We confirmed it by conducting two different tasks: (1) exploring the object surface with the index finger and (2) grasping the object surface with the thumb and the index finger.

Pneumatic Actuation in Haptic-Enabled Medical Simulators: A Review

Haptic feedback is essential for achieving virtual and augmented reality (VR/AR) systems with high fidelity and realism. Haptic-enabled VR/AR systems offer a proficient environment in which to enhance the skills of medical practitioners. While pneumatic actuation is traditionally used in heavy automation industries, haptics researchers have utilized pneumatic techniques to produce various haptic effects, i.e., stiffness feedback and contour control, and these techniques have shown promising results in the medical domain. In this paper, we focus on the use of pneumatic-actuated haptic systems in VR/AR-based medical simulators. We begin with the taxonomy of the physical-virtual continuum and discuss the role of pneumatics in medical haptic systems. Furthermore, we propose the conceptual design architecture of a pneumatic haptic system. In addition, the systematic state-of-the-art role of pneumatic haptics in medical systems is presented for different categories. In this paper, we provide a systematic review and discuss the study of pneumatics to provide guidelines for the design and development of pneumatic haptic medical systems.

Experimental evaluation of a miniature MR device for a wide range of human perceivable haptic sensations

Humans can experience a realistic and vivid haptic sensations by the sense of touch. In order to have a fully immersive haptic experience, both kinaesthetic and vibrotactile information must be presented to human users. Currently, little haptic research has been performed on small haptic actuators that can covey both vibrotactile feedback based on the frequency of vibrations up to the human-perceivable limit and multiple levels of kinaesthetic feedback rapidly. Therefore, this study intends to design a miniature haptic device based on MR fluid and experimentally evaluate its ability to convey vibrotactile feedback up to 300 Hz along with kinaesthetic feedback. After constructing a prototype device, a series of testing was performed to evaluate its performance of the prototype using an experimental setup, consisting of a precision dynamic mechanical analyzer and an accelerometer. The kinaesthetic testing results show that the prototype device can provide the force rate up to 89% at 5 V (360 mA), which can be discretized into multiple levels of ‘just noticeable difference’ force rate, indicating that the device can convey a wide range of kinaesthetic sensations. To evaluate the high frequency vibrotactile feedback performance of the device, its acceleration responses were measured and processed using the FFT analysis. The results indicate that the device can convey high frequency vibrotactile sensations up to 300 Hz with the sufficiently large intensity of accelerations that human can feel.

Determining the bias and variance of a deterministic finger-tracking algorithm.

Finger tracking has the potential to expand haptic research and applications, as eye tracking has done in vision research. In research applications, it is desirable to know the bias and variance associated with a finger-tracking method. However, assessing the bias and variance of a deterministic method is not straightforward. Multiple measurements of the same finger position data will not produce different results, implying zero variance. Here, we present a method of assessing deterministic finger-tracking variance and bias through comparison to a non-deterministic measure. A proof-of-concept is presented using a video-based finger-tracking algorithm developed for the specific purpose of tracking participant fingers during a psychological research study. The algorithm uses ridge detection on videos of the participant's hand, and estimates the location of the right index fingertip. The algorithm was evaluated using data from four participants, who explored tactile maps using only their right index finger and all right-hand fingers. The algorithm identified the index fingertip in 99.78 % of one-finger video frames and 97.55 % of five-finger video frames. Although the algorithm produced slightly biased and more dispersed estimates relative to a human coder, these differences (x=0.08 cm, y=0.04 cm) and standard deviations (σ x =0.16 cm, σ y =0.21 cm) were small compared to the size of a fingertip (1.5-2.0 cm). Some example finger-tracking results are provided where corrections are made using the bias and variance estimates.

An Applicable Platform for Web Interactive Content Hapticization

Haptic technology again receives extensive attentions recently by virtue of improvement on Internet Technology. This paper presents an applicable platform for Haptics by employing physical features of sense-of-touch through electromechanical devices and the latest attractive HTML standard specified by W3C, aims at offering new attributes and reliable communications with the ease of use for web content. In addition, the proposed platform demonstrates its significance on wrapping up fundamental rendering methodologies including Haptics and web graphical content, is a step forward in supporting study of all fields related to web-based interactive content (e.g., Haptics researchers, physicists, software engineers, and web designers). Finally, we provide a conceptual example of proposed platform and prove its proficiency on haptic data communication. The results of the experimental evaluations highlight the effectiveness, stableness, affordance and extensibility for future research.

News from the Field: Courses in Haptics

A number of haptics researchers offer courses devoted to haptics or have haptics as a major component of a course. The increasing number of these offerings is perhaps best exemplified by the tutorial held at the 2012 Haptics Symposium in Vancouver that was devoted to “Best Practices for Teaching Haptics”. This paper feature some of these courses that cover a variety of content, haptic development platforms, and target different audiences.

Mediating intimacy in long-distance relationships using kiss messaging

Intimate interactions between remotely located individuals are not well supported by conventional communication tools, mainly due to the lack of physical contact. Also, haptic research has not focused on the use of a kiss as a mode of interaction that maintains intimacy in long distance relationships. In this study, we designed and developed a haptic device called Kissenger (Kiss-Messenger) for this issue. Kissenger is an interactive device that provides a physical interface for transmitting a kiss between two remotely connected people. Each device is paired with another and the amount of force and shape of the kiss by the user is sensed and transmitted to another device that is replicated using actuators. Kissenger is designed to augment already existing remote communication technologies. Challenges in the design and development of the system are addressed through an iterative design process involving constant evaluation by users after each stage. The devices are evaluated through a short- and a long-term user study with remotely located couples. The results point to an initial acceptance of the device with feedback from the users on directions to improve the overall experience. This study discusses potential issues that designers should be aware of when prototyping for remote intimate interactions.

Design and development of a user centric affective haptic jacket

Affective haptic research is a rapidly growing field. This article intends to improve the existing literature and contribute by involving consumers directly in the design of a smart haptic jacket by adding heat, vibration actuators, and by enhancing portability. The proposed system is designed for six basic emotions: love, joy, surprise, anger, sadness, and fear. Also, it can support several interacts such as a hug, poke, tickle or touch. An online survey was designed, based on literature, and conducted on 92 respondents, who gave their opinion about the physiological impact of emotions and interactions on the human body. The results of this survey assisted in the general design and implementation of the system. 86 % of the volunteers who participated in the final experiment expressed their interest in the system and said that the quality of their multimedia experience was improved through use of the jacket. Detailed design architecture is provided, along with the details of the hardware and software used for the implementation.

Human Detection and Discrimination of Tactile Repeatability, Mechanical Backlash, and Temporal Delay in a Combined Tactile-Kinesthetic Haptic Display System

Many of the devices used in haptics research are over-engineered for the task and are designed with capabilities that go far beyond human perception levels. Designing devices that more closely match the limits of human perception will make them smaller, less expensive, and more useful. However, many device-centric perception thresholds have yet to be evaluated. To this end, three experiments were conducted, using one degree-of-freedom contact location feedback device in combination with a kinesthetic display, to provide a more explicit set of specifications for similar tactile-kinesthetic haptic devices. The first of these experiments evaluated the ability of humans to repeatedly localize tactile cues across the fingerpad. Subjects could localize cues to within 1.3 mm and showed bias toward the center of the fingerpad. The second experiment evaluated the minimum perceptible difference of backlash at the tactile element. Subjects were able to discriminate device backlash in excess of 0.46 mm on low-curvature models and 0.93 mm on high-curvature models. The last experiment evaluated the minimum perceptible difference of system delay between user action and device reaction. Subjects were able to discriminate delays in excess of 61 ms. The results from these studies can serve as the maximum (i.e., most demanding) device specifications for most tactile-kinesthetic haptic systems.

A Model for Haptic Aesthetic Processing and Its Implications for Design

Research in aesthetics typically focuses on static stimuli or stimulus properties from the visual domain leaving unanswered a great many questions on haptic aesthetics. This paper aims to give a short impression of the relevance of aesthetics for design and everyday-life decisions, then focuses on phenomena concerning haptic aesthetics in particular, for instance, top-down processes and mere exposure effects. Based on empirical findings and theoretical considerations with regard to haptic research, the paper develops a functional model of haptic aesthetics, which is explained step by step. This model assumes a continuous increase of elaborative processing through three subsequent processing stages beginning with low-level perceptual analyses that encompass an initial, unspecific exploration of the haptic material. After a subsequent, more elaborate, and specific perceptual assessment of global haptic aspects, the described process enters into deeper cognitive and emotional evaluations involving individual knowledge on the now specified haptic material. The paper closes with an applied view on design issues to explicate the importance of integrating haptic aesthetics into corresponding approaches.

Application of Psychophysical Techniques to Haptic Research

Various psychophysical methods have been used to study human haptic perception, although the selection of a particular method is often based on convention, rather than an analysis of which technique is optimal for the question being addressed. In this review, classical psychophysical techniques used to measure sensory thresholds are described as well as more modern methods such as adaptive procedures and those associated with signal detection theory. Details are provided as to how these techniques should be implemented to measure absolute and difference thresholds and factors that influence subjects' responses are noted. In addition to the methods used to measure sensory thresholds, the techniques available for measuring the perception of suprathreshold stimuli are presented. These scaling methods are reviewed in the context of the various stimulus and response biases that influence how subjects respond to stimuli. The importance of understanding the factors that influence perceptual processing is highlighted throughout the review with reference to experimental studies of haptic perception.

A new desk-top encounter-type haptic device with an actively driven pen-tablet LCD panel

In conventional haptic devices for virtual reality (VR) systems, a user interacts with a scene by handling a tool (such as a pen) using a mechanical device (i.e. an end-effector-type haptic device). In the case that the device can ‘mimic’ a VR object, the user can interact directly with the VR object without the mechanical constraint of a device (i.e. an encounter-type haptic device). A new challenge of an encounter-type haptic device is displaying the visuals and haptic information simultaneously on a single device. We are proposing a new desk-top encounter-type haptic device with an actively driven pen-tablet LCD panel. The proposed device is capable of providing pseudo-3D visuals and haptic information on a single device. As the result, the system provides to the user a sense of interaction with a real object. To develop a proof-of-concept prototype, a compact parallel mechanism was developed and implemented. The aim of this research is to propose a new concept in haptic research. In this paper, the concept, the prototype, and some preliminary evaluation tests with the proposed system are presented.