Haptic Feedback System Research Articles

Skin-integrated stretchable actuators toward skin-compatible haptic feedback and closed-loop human-machine interactions

Skin-integrated haptic interfaces that can relay a wealth of information from the machine to the human are of great interest. However, existing haptic devices are not yet able to produce haptic cues that are compatible with the skin. In this work, we present the stretchable soft actuators for haptic feedback, which can match the perception range, spatial resolution, and stretchability of the skin. Pressure-amplification structures are fabricated using a scalable self-assembly process to ensure an output pressure beyond the skin perception threshold. Due to the minimized device size, the actuator array can be fabricated with a sufficiently high spatial resolution, which makes the haptic device applicable for skin locations with the highest spatial acuity. A haptic feedback system is demonstrated by employing the developed soft actuators and highly sensitive pressure sensors. Two proof-of-concept applications are developed to illustrate the capability of transferring information related to surface textures and object shapes acquired at the robot side to the user side.

Modulation of Arm Swing Frequency and Gait Using Rhythmic Tactile Feedback.

Due to the neural coupling between upper and lower limbs and the importance of interlimb coordination in human gait, focusing on appropriate arm swing should be a part of gait rehabilitation in individuals with walking impairments. Despite its vital importance, there is a lack of effective methods to exploit the potential of arm swing inclusion for gait rehabilitation. In this work, we present a lightweight and wireless haptic feedback system that provides highly synchronized vibrotactile cues to the arms to manipulate arm swing and investigate the effects of this manipulation on the subjects' gait in a study with 12 participants (20-44 years). We found the developed system effectively adjusted the subjects' arm swing and stride cycle times by significantly reducing and increasing those parameters by up to 20% and 35%, respectively, compared to their baseline values during normal walking with no feedback. Particularly, the reduction of arms' and legs' cycle times translated into a substantial increase of up to 19.3% (on average) in walking speed. The response of the subjects to the feedback was also quantified in both transient and steady-state walking. The analysis of settling times from the transient responses revealed a fast and similar adaptation of both arms' and legs' movements to the feedback for reducing cycle time (i.e., increasing speed). Conversely, larger settling times and the time differences between arms' and legs' responses were observed due to feedback for increasing cycle times (i.e., reducing speed). The results clearly demonstrate the potential of the developed system to induce different arm-swing patterns as well as the ability of the proposed method to modulate key gait parameters through leveraging the interlimb neural coupling, with implications for gait training.

Preliminary User Evaluation of a New Dental Technology Virtual Simulation System: Development and Validation Study.

BackgroundWith the advancements in the dental health care industry, the demand for dental technicians has increased. Dental technicians should be thoroughly assessed and trained in practical skills and pass professional certification examinations to ensure that they are competent to work closely with dentists. Unfortunately, such training courses and tests are in short supply worldwide. The use of virtual simulation technology can help solve these problems.ObjectiveThis study presents a new strategic framework design for a certified dental technician practical examination called as the certified Objective Manipulative Skill Examination of Dental Technicians (OMEDT), which is based on the Objective Structured Clinical Examination (OSCE). We present the development and validation of the OMEDT system, a new virtual simulated training system, to meet the demands of the OMEDT framework. The combination of OMEDT and the OMEDT system can solve the complex problems encountered in the certified dental technician practical examination with excellent efficiency, high quality, and low cost.MethodsThe OMEDT framework design was constructed according to the OSCE guide and the Chinese vocational skill standards for dental technicians. To develop the OMEDT system, we organized a new framework based on the virtual learning network platform, the haptic feedback system, and the real-time dental training and evaluation system. The effectiveness evaluation of the OMEDT system was divided into 2 phases: in the first phase, 36 students were recruited to use the test module to finish the task and their performance data were collected and analyzed; and in the second phase, a questionnaire was administered to 30 students who used the system for their studies and graduation exams.ResultsThe OMEDT and the corresponding skill training virtual simulation OMEDT system were developed, and preliminary user evaluation was performed to assess their effectiveness and usefulness. The OMEDT system was found to improve students’ practical skills by training with the evaluation results. In addition, several key research topics were explored, including the effects of positive feedback of the knowledge of results on the improvement of the students’ skill level and the common sense transformation of educators in the virtual simulation technology environment.ConclusionsThe development of OMEDT and the OMEDT system has been completed and their effectiveness has been verified.

Haptic feedback system for postural adaptation during robotic rehabilitation of upper limb.

Although trunk compensation during stroke rehabilitation is widely studied, the proposed solutions primarily include a trunk constraint, which has several disadvantages. In this study, we have proposed a haptic feedback-based system for postural training during upper-limb motor rehabilitation. We have tested the proposed system on six healthy people in this preliminary study. Participants performed a simple 1-dimensional reaching task while their posture was being monitored. They received haptic feedback based on their trunk posture. Preliminary results revealed a significant decline in postural error (p<0.05) after the haptic-based training. The reduction in error was maintained even after haptic feedback was turned off. This study shows that haptic feedback could be a viable alternative to the traditional constraint-based methods for postural adaptation. Additional studies need to be conducted to further evaluate the influence of using such feedback strategies.

HapticLink: A Force-based Haptic Feedback System for Single and Double Lower-Limb Amputees.

Lower limb amputation affects an estimated 1.71 million people in the US. The lack of sensory feedback and proprioception often causes loss of balance which heightens the risk of falls and injury. In this presented paper, a haptic feedback system named HapticLink was developed based on the weight distribution of the prosthetic foot to increase the individual's balance and the self-attribution of the prosthesis. The repeatability and linearity of four different force sensors were tested. The FlexiForce A201 sensors were identified as the optimal choice for the parameters and scenarios investigated. HapticLink consists of four A201 sensors, a microcontroller, and four Vibration Motors (VM). The developed system can determine and convey weight distribution on a prosthetic foot to the wearer as haptic feedback. Initial tests with Lower-Limb Prosthetic (LLP) users were conducted with quantitative results (Directional, Frequency, and Manually Applied Directional Perception tests avg. 94.44%, 79.17%, and 100%) and responses from the participants indicating that HapticLink may aid during single or double lower-limb amputee ambulation after establishing haptic feedback intensity comfort. Finally, the successful qualitative tests with a double lower-limb amputee imply the haptic feedback may be sufficient without requiring sensor fusion on the part of the participant from both the VMs and the proprioception of the contralateral leg. Clinical Relevance--- This establishes the utility of a simple, stand-alone 4:4 force sensor and haptic motor feedback system to aid during single or double lower-limb amputee ambulation.

Review on Haptic Assistive Driving Systems Based on Drivers’ Steering-Wheel Operating Behaviour

With the availability of modern assistive techniques, ambient intelligence, and the Internet of Things (IoT), various innovative assistive environments have been developed, such as driving assistance systems (DAS), where the human driver can be provided with physical and emotional assistance. In this human–machine collaboration system, haptic interaction interfaces are commonly employed because they provide drivers with a more manageable way to interact with other components. From the view of control system theory, this is a typical closed-loop feedback control system with a human in the loop. To make such a system work effectively, both the driving behaviour factors, and the electrical–mechanical components should be considered. However, the main challenge is how to deal with the high degree of uncertainties in human behaviour. This paper aims to provide an insightful overview of the relevant work. The impact of various types of haptic assistive driving systems (haptic guidance and warning systems) on driving behaviour performance is discussed and evaluated. In addition, various driving behaviour modelling systems are extensively investigated. Furthermore, the state-of-the-art driving behaviour controllers are analysed and discussed in driver–vehicle–road systems, with potential improvements and drawbacks addressed. Finally, a prospective approach is recommended to design a robust model-free controller that accounts for uncertainties and individual differences in driving styles in a haptic assistive driving system. The outcome indicated that the haptic feedback system applied to the drivers enhanced their driving performance, lowered their response time, and reduced their mental workload compared to a system with auditory or visual signals or without any haptic system, despite some annoyances and system conflicts. The driving behaviour modelling techniques and the driving behaviour control with a haptic feedback system have shown good matching and improved the steering wheel’s base operation performance. However, mathematical principles, a statistical approach, and the lack of consideration of the individual differences in the driver–vehicle–road system make the modelling and the controller less robust and inefficient for different driving styles.

Development of an Integrated Haptic Sensor System for Multimodal Human–Computer Interaction Using Ultrasonic Array and Cable Robot

This paper presents the design and development of a novel haptic sensor system. It integrates cable-driven force and ultrasonic tactile feedback, which can produce multimodal haptic stimuli. The sensing element includes a Leapmotion, an ultrasonic transducer array, tension sensors, and rotary encoders, which are used to capture hand posture, project tactile points, measure cable force and length, respectively. Firstly, a 6-DOF cable-driven force feedback apparatus based on parallel mechanism is designed and ultrasonic phased array is combined to form a multimodal haptic feedback system. Secondly, a multimodal haptic fusion method for cable-driven force and ultrasonic tactile is firstly proposed to invoke realistic compound haptic sensations. To enhance the rendering effects of each subsystem, admittance control is developed for a cable robot, and a new perceived magnitude model is established for ultrasound tactile rendering. A psychophysical experiment is conducted to study the perceived characteristics of multimodal haptic stimuli. To verify the proposed system, a series of experiments were carried out, whose results indicated that the system performs well at multi-property haptic rendering and confirm the accuracy and sensitive advantage of our system in virtual reality applications. The results of our study indicate that this device has great application potential in human-computer interaction.

Modelling the compression of a soft ellipsoid fingertip.

A purely mechanical-driven haptic feedback system was developed for amputees by [G. Shi et al., IEEE Trans. Haptics, 2020, 13, 204-210]. The fingertip ellipsoid modulates the compression force and transmits it to the feedback actuator when the finger interacts with an object. In this paper, the haptic feedback system has been modelled using finite deformation theory. For the ellipsoid fingertip, the compression behaviour between two rigid, flat surfaces has been studied and can predict the force-indentation trend and deformed shape of the membrane with the contact area. For the feedback actuator, the model for the flat membrane is developed with elastic theory, in which the deformation resulting in contact area increase has been studied. The model has been validated with experimental results, which consists of the fingertip ellipsoid membrane being compressed by a rigid surface and the feedback actuator being pressurised. The results of force-indentation, pressure-indentation and the deformation of the membrane from ellipsoid modelling lay within the experimental data and fit the non-linear trend well. The results from modelling the feedback actuator have the same trend as the experimental data in the force-pressure relationship. The haptic feedback system is consistent as a functional tactile sensor after validation. We present the modelling and validation of the proposed model for the mechanical driven haptic feedback system.

DeviceD: Audience-dancer interaction via social media posts and wearable for haptic feedback.

The performative installation DeviceD utilizes a network of systems toward facilitating interaction between dancer, digital media, and audience. Central to the work is a wearable haptic feedback system able to wirelessly deliver vibrotactile stimuli, with the latter initiated by the audience through posting on Twitter social media platform; the system in use searches for specific mentions, hashtags, and keywords, with positive results causing the system to trigger patterns of haptic biofeedback across the wearable's four actuator motors. The system acts as the intermediator between the audience's online actions and the dancer receiving physical stimuli; the dancer interprets these biofeedback signals according to Laban's Effort movement qualities, with the interpretation informing different states of habitual and conscious choreographic performance. In this article, the authors reflect on their collaborative process while developing DeviceD alongside a multidisciplinary team of technologists, detailing their experience of refining the technology and methodology behind the work while presenting it in three different settings. A literature review is used to situate the work among contemporary research on interaction over internet and haptics in performance practice; haptic feedback devices have been widely used within artistic work for the past 25years, with more recent practice and research outputs suggesting an increased interest for haptics in the field of dance research. The authors detail both technological and performative elements making up the work, and provide a transparent evaluation of the system, as means of providing a foundation for further research on wearable haptic devices.

Design and Validation of a Smartphone-based Haptic Feedback System for Gait Training

This letter presents a novel vibrotactile haptic system controlled by a smartphone that can be used for gait training of older adults. Compared to previous works, the system's modularity as well as its smartphone-based controller and user interface can enhance its usability and promote regular gait training of users during their daily living. Given the prevalence of reduced stride length and speed in older adults, we developed a biomechanical data-driven approach to enable improving those outcomes via modifying their underlying surrogates. A subject study was performed by recruiting 12 young participants (19-39 years) to assess the efficacy of the haptic system and our approach based on biomechanical surrogates. It was found that the participants could significantly increase their thigh and shank extensions (i.e., the surrogates) via the feedback provided by our system, and those increases resulted in higher values of their stride length and walking speed. The results provide a clear proof-of-concept for the developed biomechanics-driven haptic system for gait training of older adults to potentially improve their mobility and living independence.

Magnetostriction-based force feedback for robot-assisted cardiovascular surgery using smart magnetorheological elastomers

Magnetorheological elastomer composites are a class of smart materials with controllable deformation by an external magnetic field. Recent studies have shown the feasibility of using magnetorheological composites for tactile feedback applications. In this study, a new haptic feedback system for regulating torque through contact friction was proposed, constitutively modeled, and experimentally validated. To this end, an analytical constitutive model for the composite was proposed and solved and was used to find the contact stress between the composite and a ferromagnetic shaft. Afterward, the proposed device was prototyped and a series of validation studies with three types of magnetorheological composites was performed. The validation studies showed that the analytical predictions for resistant torque were in fair agreement with the experimental results. Also, the proposed device was capable of generating and controlling a resistant torque of up to 115.5±0.7 mNm and haptic force of up to 5.77 N. The system showed favorable performance for haptic feedback applications in robot-assisted cardiovascular interventions.

Effectiveness of Smartwatch Guidance for High-Quality Infant Cardiopulmonary Resuscitation: A Simulation Study.

Background and objectives: As in adults, the survival rates and neurological outcomes after infant Cardiopulmonary resuscitation (CPR) are closely related to the quality of resuscitation. This study aimed to demonstrate that using a smartwatch as a haptic feedback device increases the quality of infant CPR performed by medical professionals. Materials and methods: We designed a prospective, randomized, case-crossover simulation study. The participants (n = 36) were randomly allocated to two groups: control first group and smartwatch first group. Each CPR session consisted of 2 min of chest compressions (CCs) using the two-finger technique (TFT), 2 min of rest, and 2 min of CCs using the two-thumb encircling hands technique (TTHT). Results: The primary outcome was the variation in the “proportion of optimal chest compression duration” and “compression rate” between the smartwatch-assisted and non-smartwatch-assisted groups. The secondary outcome was the variation in the “compression depth” between two groups. The proportion of optimal CC duration was significantly higher in the smartwatch-assisted group than in the non-smartwatch-assisted group. The absolute difference from 220 was much smaller in the smartwatch-assisted group (218.02) than in the non-smartwatch-assisted group (226.59) (p-Value = 0.018). Conclusion: This study demonstrated the haptic feedback system using a smartwatch improves the quality of infant CPR by maintaining proper speed and depth regardless of the compression method used.

A Haptic Feedback Actuator Suitable for the Soft Wearable Device

Gaining direct tactile sensation is becoming increasingly important for humans in human–computer interaction fields such as space robot teleoperation and augmented reality (AR). In this study, a novel electro-hydraulic soft actuator was designed and manufactured. The proposed actuator is composed of polydimethylsiloxane (PDMS) films, flexible electrodes, and an insulating liquid dielectric. The influence of two different voltage loading methods on the output characteristics of the actuator was studied. The special voltage loading method (AC voltage) enables the actuator to respond rapidly (within 0.15 s), output a stable displacement in 3 s, and remain unchanged in the subsequent time. By adjusting the voltages and frequencies, a maximum output displacement of 1.1 mm and an output force of 1 N/cm2 can be rapidly achieved at a voltage of 12 kV (20 Hz). Finally, a haptic feedback system was built to control the robotic hand to perform gripping tasks in real time, and a more realistic tactile sensation could be realized, similar to that obtained when a human directly grabs objects. Therefore, the actuator has excellent portability, robustness, rapid response, and good compatibility with the human body for human–computer interaction.

A Haptic feedback system based on leap motion controller for prosthetic hand application

Leap Motion Controller (LMC) is a gesture sensor consists of three infrared light emitters and two infrared stereo cameras as tracking sensors. LMC translates hand movements into graphical data that are used in a variety of applications such as virtual/augmented reality and object movements control. In this work, we intend to control the movements of a prosthetic hand via (LMC) in which fingers are flexed or extended in response to hand movements. This will be carried out by passing in the data from the Leap Motion to a processing unit that processes the raw data by an open-source package (Processing i3) in order to control five servo motors using a micro-controller board. In addition, haptic setup is proposed using force sensors (FSR) and vibro-motors in which the speed of these motors is proportional to the amount of the grasp force exerted by the prosthetic hand. Investigation for optimal placement of the FSRs on a prosthetic hand to obtain convenient haptic feedback has been carried out. The results show the effect of object shape and weight on the obtained response of the FSR and how they influence the locations of the sensors.

Assessment of Intuitiveness and Comfort of Wearable Haptic Feedback Strategies for Assisting Level and Stair Walking

Nowadays, lower-limb prostheses are reaching real-world usability especially on ground-level walking. However, some key tasks such as stair walking are still quite demanding. Providing haptic feedback about the foot placement on the steps might reduce the cognitive load of the task, compensating for increased dependency on vision and lessen the risk of falling. Experiments on intact subjects can be useful to define the feedback strategies prior to clinical trials, but effective methods to assess the efficacy of the strategies are few and usually rely on the emulation of the disability condition. The present study reports on the design and testing of a wearable haptic feedback system in a protocol involving intact subjects to assess candidate strategies to be adopted in clinical trials. The system integrated a sensorized insole wirelessly connected to a textile waist belt equipped with three vibrating motors. Three stimulation strategies for mapping the insole pressure data to vibrotactile feedback were implemented and compared in terms of intuitiveness and comfort perceived during level and stair walking. The strategies were ranked using a relative rating approach, which highlighted the differences between them and suggested guidelines for their improvement. The feedback evaluation procedure proposed could facilitate the selection and improvement of haptic feedback strategies prior to clinical testing.

A pilot study on locomotion training via biomechanical models and a wearable haptic feedback system

Locomotion is a fundamental human skill. Real-time sensing and feedback is a promising strategy for motion training to reconstruct healthy locomotion patterns lost due to aging or disease, and to prevent injuries. In this paper, we present a pilot study on locomotion training via biomechanical modeling and a wearable haptic feedback system. In addition, a novel simulation framework for motion tracking and analysis is introduced. This unified framework, implemented within the Unity environment, is used to analyze subject’s baseline and performance characteristics, and to provide real-time haptic feedback during locomotion. The framework incorporates accurate musculoskeletal models derived from OpenSim, closed-form calculations of muscle routing kinematics and kinematic Jacobian matrices, dynamic performance metrics (i.e., muscular effort), human motion reconstruction via inertial measurement unit (IMU) sensors, and real-time visualization of the motion and its dynamics. A pilot study was conducted in which 6 healthy subjects learned to alter running patterns to lower the knee flexion moment (KFM) through haptic feedback. We targeted three gait parameters (trunk lean, cadence, and foot strike) that previous studies had identified as having an influence on reducing the knee flexion moment and associated with increased risk of running injuries. All subjects were able to adopt altered running patterns requiring simultaneous changes to these kinematic parameters and reduced their KFM to 30–85% of their baseline values. The muscular effort during motion training stayed comparable to subjects’ baseline. This study shows that biomechanical modeling, together with real-time sensing and wearable haptic feedback can greatly increase the efficiency of motion training.

PD23-09 INITIAL EXPERIENCE OF NEW SENHANCE ROBOTIC SYSTEM IN UROLOGIC SURGERY

You have accessJournal of UrologySurgical Technology & Simulation: Instrumentation & Technology II (PD23)1 Apr 2020PD23-09 INITIAL EXPERIENCE OF NEW SENHANCE ROBOTIC SYSTEM IN UROLOGIC SURGERY LunHsiang Yuan*, ShiWei Huang, and YuWen Huang LunHsiang Yuan*LunHsiang Yuan* More articles by this author , ShiWei HuangShiWei Huang More articles by this author , and YuWen HuangYuWen Huang More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000873.09AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The use of robotic surgeries is increasing in urologic field. Recently, the Senhance robotic system, a novel robotic platform was introduced on the market. It is based on standard laparoscopic surgery, equipped with haptic feedback and eye tracking system. Currently, the surgical platform is only used in general surgery, colo-rectal surgery and gynecological surgery. This study describes the initial, single center experience, evaluating the feasibility and safety of the new robotic system in performing urologic surgeries. METHODS: From July 2019 to October 2019, total 34 patients undergoing urologic surgery with Senhance robotic system were collected. Their peri-operative data were analyzed. Indications for surgery include inguinal hernia, stone disease, ureteral stricture, renal cell carcinoma, urothelial carcinoma and prostate cancer. RESULTS: The median age was 69 years-old (42-85). Surgical procedures include 15 cases (44.1%) hernioplasty, 6 cases (17.6%) radical prostatectomy, 5 cases (14.7%) ureterolithotomy and ureteral reconstruction, 2 cases (5.8%) partial nephrectomy, 2 cases (5.8) adrenalectomy, 2 cases (5.8%) renal cysts unroofing, 1 case (2.4%) abdominal exploration for cryptorchidism, 1 case (2.4%) nephroureterectomy and bladder cuff excision. Nine cases (26.4%) were operated for malignant diseases (6 adenocarcinoma of prostate, 2 renal cell carcinoma, and 1 urothelial carcinoma) The median docking time was 10 min (8-30). The median operative time was 125 min (93-325). The median time to discharge was 7 days (3-10). The incidence of post-operative complications was 20.5% (Clavien-Dindo I/II- 7 patients) . There's no Clavien-Dindo III/IV complications. No patient was re-admitted and no patient require re-operation. CONCLUSIONS: The results showed Senhance surgical robotic system could be adopted in urologic surgery. It is safe and feasible, and could performed most urologic procedures. The learning curve is quick and its special advantage offer urologist more choices of robotic surgery. More clinical data are needed to determine whether it could provide any other benefits. Source of Funding: nil © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e467-e467 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information LunHsiang Yuan* More articles by this author ShiWei Huang More articles by this author YuWen Huang More articles by this author Expand All Advertisement PDF downloadLoading ...

Design of a Haptic Feedback System for Flight Envelope Protection

Several modern aircraft use a passive control manipulator: a spring–damper system that generates command signals to the flight control computers in combination with a flight envelope protection system that limits pilot inputs when approaching the aircraft limits. This research project aims to increase pilot awareness of this protection system through the use of force feedback on the control device, that is, haptics. This paper describes in detail how the haptic feedback works and when it triggers; another paper will discuss the results of an experimental evaluation. With the current haptic design, pilots can get five cues: first, a discrete force cue when approaching the limits; second, an increased spring coefficient for control deflections that bring the aircraft closer to its limits; third, a stick shaker for low velocities; fourth, if a low-velocity condition requires an input, the stick is moved forward to the desired control input; and finally, the stick follows the automatic Airbus “pitch-up” command during an overspeed condition. This novel system is expected to help pilots correctly assess the situation and decide upon the right control action. It will be evaluated in two scenarios close to the flight envelope limits: a windshear and an icing event.

Application of piezoelectric actuator to simplified haptic feedback system

The lack of haptic feedback in minimally invasive surgery results in the dependence on high-resolution images. This study used a simplified working abstraction of a haptic feedback system, including a master manipulator, a console table, a slave indenter, and a control algorithm to construct a scalable platform for a palpation device. A piezoelectric actuator was designed using finite element simulation, and was added to the master manipulator to produce thrust force against the user’s finger pressing. Button motion on the master manipulator was synchronized with the slave indenter's linear movement. If the indenter contacted an object, the loading was used to adjust the thrust force of the piezoelectric actuator in the console table. This function can be developed into a model of haptic perception, like palpating an object. Instead of a human operator, this study used a reciprocating mechanism to simulate finger pressing and tested the haptic feedback system under different contact conditions: two indentation speeds (0.84 mm/s, 4.2 mm/s) and two springs of different stiffness (214.6 N/m, 474.3 N/m). The results showed that our haptic feedback system allows estimating the stiffness of objects. Lower indentation speeds disclosed a clearer contact information. The piezoelectric actuator yielded better efficiency at the resonant frequency and smaller preload. A smaller friction force could increase the response speed. The response time of whole system was 0.36 s and the variation of the thrust force of one piezoelectric actuator was in a quite small range of 0.3 N. To improve the haptic feedback system, to integrate more actuators and to develop the embedded controller module were the potential solution.

Fluidic Haptic Interface for Mechano-Tactile Feedback.

Notable advancements have been achieved in providing amputees with sensation through invasive and non-invasive haptic feedback systems such as mechano-, vibro-, electro-tactile and hybrid systems. Purely mechanical-driven feedback approaches, however, have been little explored. In this paper, we now created a haptic feedback system that does not require any external power source (such as batteries) or other electronic components (see Fig.1 ). The system is low-cost, lightweight, adaptable and robust against external impact (such as water). Hence, it will be sustainable in many aspects. We have made use of latest multi-material 3D printing technology (Stratasys Objet500 Connex3) being able to fabricate a soft sensor and a mechano-tactile feedback actuator made of a rubber (TangoBlack Plus) and plastic (VeroClear) material. When forces are applied to the fingertip sensor, fluidic pressure inside the system acts on the membrane of the feedback actuator resulting in mechano-tactile sensation. Our [Formula: see text] feedback actuator is able to transmit a force range between 0.2 N (the median touch threshold) and 2.1 N (the maximum force transmitted by the feedback actuator at a 3 mm indentation) corresponding to force range exerted to the fingertip sensor of 1.2-18.49 N.