Modeling of micro-scale touch sensations for use with haptically augmented reality

Possessing dexterity and sensory perceptions, the human hand is a versatile tool that can grasp, hold, and manipulate objects using various postures and forces interacting with the environment. Many industrial tasks are replacing human hands with anthropomorphic robotic hands. In skillful tasks such as micro surgical operations, a master-slave interface system of robotic hands is required to emulate a human hand\u27s dexterity by using glove controllers with force sensors for telemanipulation. Although these interface techniques are widely applied for large scale robots, little has been accomplished for micro-scale robots due to the constraints and complexity imposed by miniaturization. To provide sensible haptic control and feedback from robots at the micro-level, this work investigates the intricacies associated with the use of micro-scale robotic actuators with the intention of using them with haptic feedback systems. This work also develops a system model to test the ability of computing elements that emulate a microrobotic hand\u27s tactile perception of stiffness. An interface glove was used to collect control data from the user, which was used alongside a Matlab model to simulate the operation and control of two different microhand designs. In order to control the microhand device accurately, feedback from simulated sensors was used to affect the airflow of the pneumatic system driving the displacement of the microhand. Four major components were developed for the overall system. The glove interface gives the operator a method to interact with the system. The microhand modeling took place in two components. The first component was the model of the microhand itself. The other component needed was a pneumatic subsystem to drive the microhand operation. The final major component developed was a graphical user interface to give the operator feedback as to what is happening in the target environment. The integration of all of these components allows for experimentation of the intricacies of operating with these microhand devices. The investigation of this micro-haptic system shows that some parameters make the system perform faster and more accurately than others. Metrics such as percent error and settling time of the displacement of one micro-finger are shown to measure success of each method. Future improvements for this system could include the integration of pneumatically controlled balloon micro-actuators with the operator\u27s glove interface or implementing more accurate contact mechanics into the model

A Review of Smart Materials in Tactile Actuators for Information Delivery

As the largest organ in the human body, the skin provides the important sensory channel for humans to receive external stimulations based on touch. By the information perceived through touch, people can feel and guess the properties of objects, like weight, temperature, textures, and motion, etc. In fact, those properties are nerve stimuli to our brain received by different kinds of receptors in the skin. Mechanical, electrical, and thermal stimuli can stimulate these receptors and cause different information to be conveyed through the nerves. Technologies for actuators to provide mechanical, electrical or thermal stimuli have been developed. These include static or vibrational actuation, electrostatic stimulation, focused ultrasound, and more. Smart materials, such as piezoelectric materials, carbon nanotubes, and shape memory alloys, play important roles in providing actuation for tactile sensation. This paper aims to review the background biological knowledge of human tactile sensing, to give an understanding of how we sense and interact with the world through the sense of touch, as well as the conventional and state-of-the-art technologies of tactile actuators for tactile feedback delivery

A Review of Cooperative Actuator and Sensor Systems Based on Dielectric Elastomer Transducers

This paper presents an overview of cooperative actuator and sensor systems based on dielectric elastomer (DE) transducers. A DE consists of a flexible capacitor made of a thin layer of soft dielectric material (e.g., acrylic, silicone) surrounded with a compliant electrode, which is able to work as an actuator or as a sensor. Features such as large deformation, high compliance, flexibility, energy efficiency, lightweight, self-sensing, and low cost make DE technology particularly attractive for the realization of mechatronic systems that are capable of performance not achievable with alternative technologies. If several DEs are arranged in an array-like configuration, new concepts of cooperative actuator/sensor systems can be enabled, in which novel applications and features are made possible by the synergistic operations among nearby elements. The goal of this paper is to review recent advances in the area of cooperative DE systems technology. After summarizing the basic operating principle of DE transducers, several applications of cooperative DE actuators and sensors from the recent literature are discussed, ranging from haptic interfaces and bio-inspired robots to micro-scale devices and tactile sensors. Finally, challenges and perspectives for the future development of cooperative DE systems are discussed

Mems sensors controlled haptic forefinger robotic aid

The ability to feel the world through the tools we hold is Haptic Touch. The concept of sensory elements transforming information into touch experience by interacting with things remotely is motivating and challenging. This paper deals with the design and implementation of fore finger direction based robot for physically challenged people, which follows the direction of the Forefinger. The path way of the robot may be either point-to-point or continuous. This sensor detects the direction of the forefinger and the output is transmitted via RF transmitter to the receiver unit. In the receiver section RF receiver which receives corresponding signal will command the microcontroller to move the robot in that particular direction. The design of the system includes microcontroller, MEMS sensor and RF technology. The robot system receives the command from the MEMS sensor which is placed on the fore finger at the transmitter section. Therefore the simple control mechanism of the robot is shown. Experimental results for fore finger based directional robot are enumerated

Toward wearable pneumatic haptic devices for microscale force feedback applications

The addition of haptic feedback to systems and devices allows a human user to gain a more complete understanding of the remote environment they are working in. Several applications, such as robotic minimally invasive surgery (MIS) and virtual reality gaming, have drawn interests for integrating haptic or tactile feedback onto remote operating tools. While both research studies and commercial products have clearly demonstrated the benefits of adding haptic feedback, many open questions remain for reaching the full potential of haptic feedback. This research focuses on investigating how light-weight, low-cost pneumatic haptic devices can be deployed on human hands, possibly in multiple locations, to enhance user comprehension of force feedback. The aim is to enhance the understanding of microscale pneumatic devices in their potential and limitations as a wearable haptic feedback system. This work investigates the design, construction, and testing of a binary pneumatic tactile display. Pneumatically actuated devices are chosen because they are light-weight, low-cost, and less-invasive in nature. Arrays of pneumatic balloons of different sizes were designed and constructed by taking into consideration the ease of the fabrication process and the effectiveness of feedback when placed on human hands. Human perception experiments were performed to test the pneumatic balloon arrays to determine the potential of providing binary haptic feedback. The results showed differences in sensitivity due to the location where the balloon array is placed as well as the size of the device. In addition, it appears that the use of multiple balloon arrays placed in different parts of a human hand can improve the overall effectiveness of the feedback, even if they are not placed on the most sensitive areas. Lastly, the experiments demonstrated the potential of using multiple pneumatic balloon arrays to produce identifiable binary patterns

A Model that Predicts the Material Recognition Performance of Thermal Tactile Sensing

Tactile sensing can enable a robot to infer properties of its surroundings, such as the material of an object. Heat transfer based sensing can be used for material recognition due to differences in the thermal properties of materials. While data-driven methods have shown promise for this recognition problem, many factors can influence performance, including sensor noise, the initial temperatures of the sensor and the object, the thermal effusivities of the materials, and the duration of contact. We present a physics-based mathematical model that predicts material recognition performance given these factors. Our model uses semi-infinite solids and a statistical method to calculate an F1 score for the binary material recognition. We evaluated our method using simulated contact with 69 materials and data collected by a real robot with 12 materials. Our model predicted the material recognition performance of support vector machine (SVM) with 96% accuracy for the simulated data, with 92% accuracy for real-world data with constant initial sensor temperatures, and with 91% accuracy for real-world data with varied initial sensor temperatures. Using our model, we also provide insight into the roles of various factors on recognition performance, such as the temperature difference between the sensor and the object. Overall, our results suggest that our model could be used to help design better thermal sensors for robots and enable robots to use them more effectively.Comment: This article is currently under review for possible publicatio

TIMS: A Tactile Internet-Based Micromanipulation System with Haptic Guidance for Surgical Training

Microsurgery involves the dexterous manipulation of delicate tissue or fragile structures such as small blood vessels, nerves, etc., under a microscope. To address the limitation of imprecise manipulation of human hands, robotic systems have been developed to assist surgeons in performing complex microsurgical tasks with greater precision and safety. However, the steep learning curve for robot-assisted microsurgery (RAMS) and the shortage of well-trained surgeons pose significant challenges to the widespread adoption of RAMS. Therefore, the development of a versatile training system for RAMS is necessary, which can bring tangible benefits to both surgeons and patients. In this paper, we present a Tactile Internet-Based Micromanipulation System (TIMS) based on a ROS-Django web-based architecture for microsurgical training. This system can provide tactile feedback to operators via a wearable tactile display (WTD), while real-time data is transmitted through the internet via a ROS-Django framework. In addition, TIMS integrates haptic guidance to `guide' the trainees to follow a desired trajectory provided by expert surgeons. Learning from demonstration based on Gaussian Process Regression (GPR) was used to generate the desired trajectory. User studies were also conducted to verify the effectiveness of our proposed TIMS, comparing users' performance with and without tactile feedback and/or haptic guidance.Comment: 8 pages, 7 figures. For more details of this project, please view our website: https://sites.google.com/view/viewtims/hom

Synthetic and bio-artificial tactile sensing: a review

This paper reviews the state of the art of artificial tactile sensing, with a particular focus on bio-hybrid and fully-biological approaches. To this aim, the study of physiology of the human sense of touch and of the coding mechanisms of tactile information is a significant starting point, which is briefly explored in this review. Then, the progress towards the development of an artificial sense of touch are investigated. Artificial tactile sensing is analysed with respect to the possible approaches to fabricate the outer interface layer: synthetic skin versus bio-artificial skin. With particular respect to the synthetic skin approach, a brief overview is provided on various technologies and transduction principles that can be integrated beneath the skin layer. Then, the main focus moves to approaches characterized by the use of bio-artificial skin as an outer layer of the artificial sensory system. Within this design solution for the skin, bio-hybrid and fully-biological tactile sensing systems are thoroughly presented: while significant results have been reported for the development of tissue engineered skins, the development of mechanotransduction units and their integration is a recent trend that is still lagging behind, therefore requiring research efforts and investments. In the last part of the paper, application domains and perspectives of the reviewed tactile sensing technologies are discussed

A Review of Non-Invasive Haptic Feedback stimulation Techniques for Upper Extremity Prostheses

A sense of touch is essential for amputees to reintegrate into their social and work life. The design of the next generation of the prostheses will have the ability to effectively convey the tactile information between the amputee and the artificial limbs. This work reviews non-invasive haptic feedback stimulation techniques to convey the tactile information from the prosthetic hand to the amputee’s brain. Various types of actuators that been used to stimulate the patient’s residual limb for different types of artificial prostheses in previous studies have been reviewed in terms of functionality, effectiveness, wearability and comfort. The non-invasive hybrid feedback stimulation system was found to be better in terms of the stimulus identification rate of the haptic prostheses’ users. It can be conclude that integrating hybrid haptic feedback stimulation system with the upper limb prostheses leads to improving its acceptance among users