A 3D Printed Soft Robotic Monolithic Unit for Haptic Feedback Devices

Interaction with computers and virtual environments is almost totally based on visual displays, along with auditory feedback. Somesthetic feedback, a necessary feature in all other skilled activity, is usually absent. Haptic interfaces attempt to solve this problem by coupling the human sense of touch with a computer-generated world. Haptics is the science of applying tactile sensation and kinesthesis to interaction with computer applications. By using special input/output devices (joysticks, data gloves, or other devices), users can receive feedback from computer applications in the form of sensations felt in the hand or other parts of the body. These sensations include forces, vibrations and/or motions. The aim of this tutorial is to provide participants with an overview of the technical aspects of haptic feedback and provide information about different haptic feedback devices and applications of these devices using virtual reality and computer simulations for motor rehabilitation, learning and teleoperation. The tutorial will include opportunities for hands-on practice with haptic devices and different environments. The haptic devices available for hands-on practice will include the Novint Falcon, and the SensAble OMNI devices.

The haptic interface or force feedback device improves the quality of human computer interaction by accommodating the sense of touch in a computer simulation. A haptic device enables a two way communication between the user and the host computer. The applications of force feedback device cover a wide area such as in medical training, systems for the visually impaired, engineering research, and creative art-work. The role of haptic feedback varies depending on the applications in question and the devices used. This includes haptic as a teaching tool, and a communication aid. Despite the benefits of haptic feedback, its deployment to support interactions in a virtual environment is still slow. This is due to the high cost of the haptic devices in the market. We address this issue by presenting a conceptual framework in designing and implementing a cost-effective haptic device; building on similar concepts obtained from existing technologies. The device is developed using those gadgets that are mainly available in-house. It is projected that haptic feedback generated from the device could benefit teaching abstract concepts to students.

Haptic feedback is important to improve the operability of virtual objects. However, AR systems with haptic feedback are still not many. Moreover, users cannot perform tasks that need large workspaces in those systems because of physical constraints from haptic feedback devices. In this paper, we combined a wearable haptic device and a marker-less AR technology to develop an AR system in which users can perform activities that need large workspaces. Differences of the operability of virtual objects in an assembly task of large machines are examined to evaluate effects of the haptic feedback in this system. The result indicates that haptic feedback is effective and users can perform activities that need large space in this system.

In a collaborative scenario, the communication between humans and robots is a fundamental aspect to achieve good efficiency and ergonomics in the task execution. A lot of research has been made related to enabling a robot system to understand and predict human behaviour, allowing the robot to adapt its motion to avoid collisions with human workers. Assuming the production task has a high degree of variability, the robot’s movements can be difficult to predict, leading to a feeling of anxiety in the worker when the robot changes its trajectory and approaches since the worker has no information about the planned movement of the robot. Additionally, without information about the robot’s movement, the human worker cannot effectively plan own activity without forcing the robot to constantly replan its movement. We propose a novel approach to communicating the robot’s intentions to a human worker. The improvement to the collaboration is presented by introducing haptic feedback devices, whose task is to notify the human worker about the currently planned robot’s trajectory and changes in its status. In order to verify the effectiveness of the developed human-machine interface in the conditions of a shared collaborative workspace, a user study was designed and conducted among 16 participants, whose objective was to accurately recognise the goal position of the robot during its movement. Data collected during the experiment included both objective and subjective parameters. Statistically significant results of the experiment indicated that all the participants could improve their task completion time by over 45% and generally were more subjectively satisfied when completing the task with equipped haptic feedback devices. The results also suggest the usefulness of the developed notification system since it improved users’ awareness about the motion plan of the robot.

Visual representations are used in various digitization processes to display objects in immersive environments. In industrial environments, the self-representation can be very helpful when reviewing 3D models to conform realistic proportions, particularly in combi-nation with haptic feedback that goes beyond vibrating controllers. For instance, haptic feedback in combination with a virtual representation supports working on use cases where collision is an important part to maintain data quality. To understand the dependency of both, we conducted a pilot study with 15 users from the automotive sector to examine the influence of upper limb representations on haptic feedback in Virtual Reality. Each participant was assigned with one of three upper limb representations which was used in different scenarios using haptic feedback devices. Overall, we found that the realistic arm representation was rated highest in terms of perceived realism and achieved the best task performance.

Soft robotics and pneumatic actuation present opportunities for lightweight wearable haptic devices that provide distributed touch feedback to the skin. Ideally, such devices would be easily donned and doffed, since permanent coverage of a large area of the skin is undesirable. Here we present the design and evaluation of a concept device called HapWRAP: a growing haptic device constructed from flexible low density polyethylene. Controlled air flow through tubes and pouches allows HapWRAP to grow out of a compact housing unit and provide a combination of directional and force feedback to a user. When activated, HapWRAP grows up and around the forearm; its loops form a temporary sleeve. After growth, pneumatic actuators inflate and deflate to stimulate mechanoreceptors in the skin at distinguishable locations. This paper describes the design and manufacturing of HapWRAP, reports its performance metrics, and tests its suitability as a haptic feedback device. Participants were able to interpret force and direction cues from HapWRAP with 92.5% accuracy. These findings suggest that HapWRAP can be successfully used for applications where both force and direction cues are necessary.

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.

Peg-in-hole is a task of product assembly. Robots insert the component (called “peg”) into the hole. In this paper, we tackle peg-in-hole with an uncertainty of hole position. Previous works search hole positions to insert pegs into uncertain holes. However, these methods have problems: annotation cost, positional accuracy, and long search time. Therefore, we use imitation learning (IL) which teaches robots through human teleoperation. IL provides the following benefits: lower annotation costs, rough visual servo, and an ability to find accurate hole positions by trial and error of insertion. However, current image-based IL cannot teach force perception to robots without a haptic feedback device. To solve this problem, we focused on pseudo-haptics. Pseudo-haptics is a force presentation method that does not require a mechanical feedback device. We propose a “Pseudo-haptics Module (PHM)” to feel the robot's pseudo-haptics. The module is designed from the process by which humans perceive pseudo-haptics. Our method with PHM is 7.7% higher peg-in-hole success than simple CNN.

The American Board of Orthopaedic Surgery has mandated dedicated skills training for first-year orthopedic surgical residents.1 Most residency programs address this requirement with training exercises with cadavers and plastic foam bones. Some programs incorporate one or more simulators in their skills training, including several sophisticated virtual reality simulators and a variety of low-tech simulators. Simulators are helpful because they can provide repeatable educational experiences and quantitative performance assessment. Unfortunately, few simulators have been developed for orthopedic trauma skills training. Even fewer simulators have been developed and validated with more advanced students, such as residents in their 3rd or 4th year of training, and for more complex surgeries. In contrast to the completely virtual surgical simulation using haptic feedback devices and sophisticated renderings of soft tissue deformation, our group has chosen to use physical models, real surgical instruments and position tracking in conjunction with virtual reality.2–4 The physical models provide experience with the surgical tools, and enable more realistic hand movements and haptic cue feedback.

The tactile sensation is the human interact with machines in the form of felt sensations in the hand or other parts of body skin. This paper presents a film type actuator for haptic feedback devices, based on electrostatic actuation of plasticized cellulose acetate stacked membranes actuator, which is fabricated and evaluated for suitability of haptic feedback devices. The stacked membranes actuator shows many promising properties such as high transparency, lightweight, wide range of actuation frequency and high vibration acceleration for instance. The actuator structure shows intense vibration acceleration due to several layers of stacked membranes associated with the intensified electrostatic attraction force between chargeable cellulose acetate membranes. Experiment for measuring vibrational acceleration was conducted over a wide frequency range and actuation voltage to prove actuator’s great potential application as tactile actuator of haptic feedback devices. In addition, the operating principle, fabrication method and performance measurements are explained in details.

A key factor for reliable object manipulation is the tactile information provided by the skin of our hands. As this sensory information is so essential in our daily life it should also be provided during teleoperation of robotic devices or in the control of myoelectric prostheses. It is well-known that feeding back the tactile information to the user can lead to a more natural and intuitive control of robotic devices. However, in some applications it is difficult to use the hands as natural feedback channels since they may already be overloaded with other tasks or, e.g., in case of hand prostheses not accessible at all. Many alternatives for tactile feedback to the human hand have already been investigated. In particular, one approach shows that humans can integrate uni-directional (normal) force feedback at the toe into their sensorimotor-control loop. Extending this work, we investigate the human's capability to discriminate spatial forces at the bare front side of their toe. A state-of-the-art haptic feedback device was used to apply forces with three different amplitudes—2 N, 5 N, and 8 N—to subjects' right big toes. During the experiments, different force stimuli were presented, i.e., direction of the applied force was changed, such that tangential components occured. In total the four directions up (distal), down (proximal), left (medial), and right (lateral) were tested. The proportion of the tangential force was varied corresponding to a directional change of 5° to 25° with respect to the normal force. Given these force stimuli, the subjects' task was to identify the direction of the force change. We found the amplitude of the force as well as the proportion of tangential forces to have a significant influence on the success rate. Furthermore, the direction right showed a significantly different successrate from all other directions. The stimuli with a force amplitude of 8 N achieved success rates over 89% in all directions. The results of the user study provide evidence that the subjects were able to discriminate spatial forces at their toe within defined force amplitudes and tangential proportion.

Research in the field of 3D printing and water industry, in particular, on the fabrication and evaluation of feed spacers produced via 3D printing, rapid prototyping or additive manufacturing (AM) techniques is presented in this thesis. Feed spacer is a mesh-like structure placed between membrane sheets to create channels for fluid flow in a spiral wound membrane module (SWM). It has an important role in the hydrodynamic conditions of a SWM, which serves to facilitate mass transfer in the feed channel by generating vortex and promoting mixing. The mass transfer is critical in reducing the concentration polarisation phenomenon in membrane processes, which is often associated with membrane fouling. However, the challenges of commercial feed spacers include the trade-off between mass transfer and pressure drop along the channel that leads to the rise in energy demand as well as their impact on membrane fouling. Many studies via computational fluid dynamics (CFD) simulations have shown that spacers with complex structures have great potential in enhancing the mass transfer. However, conventional method of spacer manufacturing by extrusion could not realise the complicated designs of spacers. In this work, the 3D printing technology is employed as a tool to fabricate novel feed spacers with structures that maximise the mass transfer while minimise the channel pressure drop. It is nevertheless important to note that there are limitations in current AM technology. A link between the design and fabrication i.e. printability and surface finish properties of spacers was established. The printability of polypropylene (PP) which is the representative material of spacers was also investigated. The fabricated spacers were evaluated in terms of flux and pressure drop. Direct observation through the membrane (DOTM) technique was also used to study the impact of different 3D printed spacers on the critical flux of particles. Among the 3 broad classes of solid, liquid, powder based 3D printing techniques, the liquid based Polyjet technique was found to give the most accurate representation of the intended design while the solid based FDM (Fused Deposition Modeling) technique produced spacers that showed the greatest deviation from the specifications. On the other hand, the improvement in mass transfer by the FDM printed spacer was unexpectedly the greatest among the three 3D printed spacers, due to the ‘randomness’ in the strand of spacer. In addition, the surface finish of the spacers was found to have an effect on the critical flux, specifically, the anisotropic surface finish of FDM and semi-anisotropic surface finish of Polyjet. Biofouling potential was discovered to be correlated to the surface roughness of samples. Among which, Polyjet and SLS printed samples have greater bacteria attachment due to their higher microscale roughness. Eventually, three design considerations for developing 3D printed novel spacers were recommended. A series of existing (i.e., taken from the literatures), modified and innovative spacer structures, compared with commercial feed spacer, were examined to identify the basis form of spacer structure with the greatest potential. Further optimization of the selected structure was conducted to improve the spacer performance. With the primary structure made up of sinusoidal curves and secondary structures consisting cylindrical protrusions along the curve, the novel spacer S12 showed an improvement of 18% at power number, Pn=106, and 25% at Pn= 105 in mass transfer compared to commercial spacer. With this optimal design, a smart multi-material spacer was developed by designing the primary structure with a rigid material and the secondary structures with flexible materials. The multi-material responsive spacer with Tangoblackplus as the flexible material was able to lower the flux decline due to bentonite fouling by 7.6% as compared to the commercial spacer and 5.2% when compared to the single rigid material spacer. This indicates that a spacer with flexible filaments has a beneficial effect on fouling reduction. The flexible properties of the selected section on the spacer allow dynamic movement under varying flow rate, which creates a “sweeping” effect that disrupts the boundary layers and prevents foulants from accumulating near spacer filaments and on the membrane surface, thereby mitigating fouling. These favourable findings have contributed as one of the pioneering work in this interdisciplinary field.

The rapid proliferation of novel interaction paradigms—including Extended Reality (XR), tangible and natural user interfaces, and haptic systems—together with evolving user experience attributes such as emotional, social, and collaborative interactions, has fundamentally transformed human–computer interaction. These interaction modalities, increasingly integrated with artificial intelligence, expose the limitations of traditional usability and UX evaluation methods developed for conventional graphical user interfaces. Human–AI interaction introduces distinct design challenges related to transparency, explainability, user trust, and shared control, requiring evaluation approaches that shift from technology-centered assessment toward genuinely human-centered analysis.This research proposes a metric-based, AI-powered evaluation platform designed to systematically test and benchmark contemporary user interfaces and interaction modalities. The platform employs enhanced event logging and behavioral coding mechanisms to capture comprehensive multimodal interaction data, including task performance metrics, behavioral patterns, temporal action sequences, gaze trajectories, gesture dynamics, and physiological responses. Machine learning models analyze this multidimensional data to predict standard usability attributes—efficiency, effectiveness, and satisfaction as defined by ISO 9241-11—alongside emerging UX dimensions such as cognitive load, emotional engagement, and social presence.The platform architecture integrates high-performance XR-capable computing hardware with professional-grade graphics processing, multi-monitor visualization, eye-tracking sensors, haptic feedback devices, motion-capture systems, and biometric sensing infrastructure. Data collection is supported by curated training datasets derived from prior usability studies, expert heuristic evaluations, standardized task baselines, and cross-cultural UX assessment data. A custom-engineered, shock-resistant, transportable case with integrated power management and modular connectivity enables rapid deployment across laboratory, field, and organizational contexts, addressing ecological validity limitations inherent in traditional lab-based usability testing.Automated usability evaluation is driven by a hybrid AI framework combining three complementary models. Random Forest ensemble classifiers provide robust prediction across heterogeneous interaction data while offering interpretable feature importance measures to identify key usability determinants. Long Short-Term Memory (LSTM) networks model temporally ordered interaction sequences, enabling detection of behavioral signatures associated with confusion, flow states, hesitation, and error recovery. Support Vector Machines with radial basis function kernels capture complex non-linear relationships in high-dimensional usability data and perform effectively under limited expert-labeled training conditions.The central hypothesis posits that AI-driven automated usability evaluation can achieve accuracy and reliability comparable to expert-conducted heuristic evaluations and cognitive walkthroughs, validated through controlled A/B experiments comparing automated predictions with expert assessments across diverse interface types and user populations.By democratizing access to rigorous UX evaluation through automation, multimodal sensing, and portable deployment, the proposed platform aims to accelerate iterative design cycles for emerging interactive and human–AI systems while maintaining methodological rigor comparable to expert evaluation.

For pt. 1 see ibid., p.526-9 (1996). This paper describes the initial performance evaluation of a tactile feedback actuator introduced in pt. 1. An adaptive PI algorithm using continuously variable gain scheduling helps to compensate for nonlinearities in the solenoid actuator. The closed-loop behavior meets performance specifications, but the mass added to the force-reflecting haptic interface degrades its performance. Improvements in future prototypes may reduce the mass added by the tactile feedback hardware by over 30%. The work concludes with recommendations for psychophysical research that will increase understanding of human performance in tasks using haptic feedback devices.

Wearable haptic feedback devices for virtual reality, human-robot interaction, and motion guidance require lightweight actuators that display clearly discernible cues to the user. These goals motivate the design of WRAP, a wearable, pneumatically actuated haptic feedback device. WRAP displays a variety of tactile sensations to the user by inflating a thermoplastic pneumatic actuator in direct contact with the skin. This paper describes the design and construction of WRAP, shows its effectiveness in indicating direction cues to users, and demonstrates two other appUcations for WRAP in image-guided medical interventions and human-computer interaction. Users were able to identify translation and rotation cues from WRAP with 99.4% accuracy. Our results suggest that WRAP is suitable for a variety of wearable and portable applications in which direction cues are beneficial.