Tactor devices : using tactile interface designs for mobile digital appliances : a practice-based research thesis for the fulfilment of a Master of Design degree, College of Design, Fine Arts, and Music, Massey University, Wellington

This Thesis focuses the potential of communication interfaces that use tactors (tactile actuators) to improve user interactions with mobile digital devices which are currently based on audio and visual technologies. It presents two product concepts, which use tactile signals to enable new ways in tele-operations, such as tactile telecommunication and tactile navigation. Tactor interfaces, although still in its infancy as elements of modern digital communication and technology, have considerable potential for the future as designers attempt to maximise the use of all human senses in people's interaction with technology. Only the military and a few entertainment companies have introduced tactile signals into Human-Computer Interactions (HCI). Human touch perception uses the hands as the main sensing organs. They perceive tactile signals while handling, typing or navigating with digital devices and receive direct confirmation of physical actions. In contrast to other senses, touch perceptions are based on interactions with the sensed objects. The study analyses, experiments and evaluates if these interactions are useful in interface designs and recommends how tactile stimulations can be introduced to interface designs besides images and sounds that dominate the control of current digital appliances. Tactile actuators and sensors enable devices to use tactile signals, such as impulses and vibrations, to communicate with the users. Users and tactor devices will be able to communicate in a physical and direct way. Touch reflective interfaces, could react like living creatures that respond to touch, for example a cat that starts purring when touched. Digital product design is always challenged to create human-computer interactions that meet people's needs. Designing digital devices is difficult because they are not necessarily three-dimensional objects. They are stimulator of the human senses and can be as small as the sensing nerve endings that detect sensations. By miniaturisation, form and function become invisible and Product Design is increasingly incorporating Process Design that explores and enables new interactions between users and products to work interactively and efficiently. The study is divided into four chapters: Chapter 1 gives an introduction to the thesis. Chapter 2 presents a survey on current literature which examines the five human senses to define the limits and possibilities in interface design. It reviews current research on materials and technologies as well as the psychology and physiology of touch as a potential sense in human-computer interactions. It evaluates the technical feasibilty of tactile signal performances and how they could be used as tele-touch codes in navigation and telecommunication. Chapter 3 is focused on primary research undertaken to extend the knowledge in tactile sensing. It includes experiments, questionnaires, and concepts that give examples how tactor interfaces can be used in tele-operations. This section focuses on specific user groups, that may primarily benefit from tactile signal transmissions, such as sight and hearing-impaired people or professionals who have to deal with limited perceptions like fire fighters, for example. These case studies are aimed at exploring and expanding a wider range of possibilities in tactile device innovations in the networked society. Chapter 4 gives a conclusion of the research

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

Prevalence of haptic feedback in robot-mediated surgery : a systematic review of literature

© 2017 Springer-Verlag. This is a post-peer-review, pre-copyedit version of an article published in Journal of Robotic Surgery. The final authenticated version is available online at: https://doi.org/10.1007/s11701-017-0763-4With the successful uptake and inclusion of robotic systems in minimally invasive surgery and with the increasing application of robotic surgery (RS) in numerous surgical specialities worldwide, there is now a need to develop and enhance the technology further. One such improvement is the implementation and amalgamation of haptic feedback technology into RS which will permit the operating surgeon on the console to receive haptic information on the type of tissue being operated on. The main advantage of using this is to allow the operating surgeon to feel and control the amount of force applied to different tissues during surgery thus minimising the risk of tissue damage due to both the direct and indirect effects of excessive tissue force or tension being applied during RS. We performed a two-rater systematic review to identify the latest developments and potential avenues of improving technology in the application and implementation of haptic feedback technology to the operating surgeon on the console during RS. This review provides a summary of technological enhancements in RS, considering different stages of work, from proof of concept to cadaver tissue testing, surgery in animals, and finally real implementation in surgical practice. We identify that at the time of this review, while there is a unanimous agreement regarding need for haptic and tactile feedback, there are no solutions or products available that address this need. There is a scope and need for new developments in haptic augmentation for robot-mediated surgery with the aim of improving patient care and robotic surgical technology further.Peer reviewe

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

Device modelling for bendable piezoelectric FET-based touch sensing system

Flexible electronics is rapidly evolving towards devices and circuits to enable numerous new applications. The high-performance, in terms of response speed, uniformity and reliability, remains a sticking point. The potential solutions for high-performance related challenges bring us back to the timetested silicon based electronics. However, the changes in the response of silicon based devices due to bending related stresses is a concern, especially because there are no suitable models to predict this behavior. This also makes the circuit design a difficult task. This paper reports advances in this direction, through our research on bendable Piezoelectric Oxide Semiconductor Field Effect Transistor (POSFET) based touch sensors. The analytical model of POSFET, complimented with Verilog-A model, is presented to describe the device behavior under normal force in planar and stressed conditions. Further, dynamic readout circuit compensation of POSFET devices have been analyzed and compared with similar arrangement to reduce the piezoresistive effect under tensile and compressive stresses. This approach introduces a first step towards the systematic modeling of stress induced changes in device response. This systematic study will help realize high-performance bendable microsystems with integrated sensors and readout circuitry on ultra-thin chips (UTCs) needed in various applications, in particular, the electronic skin (e-skin)

Tactile sensing chips with POSFET array and integrated interface electronics

This work presents the advanced version of novel POSFET (Piezoelectric Oxide Semiconductor Field Effect Transistor) devices based tactile sensing chip. The new version of the tactile sensing chip presented here comprises of a 4 x 4 array of POSFET touch sensing devices and integrated interface electronics (i.e. multiplexers, high compliance current sinks and voltage output buffers). The chip also includes four temperature diodes for the measurement of contact temperature. Various components on the chip have been characterized systematically and the overall operation of the tactile sensing system has been evaluated. With new design the POSFET devices have improved performance (i.e. linear response in the dynamic contact forces range of 0.01–3N and sensitivity (without amplification) of 102.4 mV/N), which is more than twice the performance of their previous implementations. The integrated interface electronics result in reduced interconnections which otherwise would be needed to connect the POSFET array with off-chip interface electronic circuitry. This research paves the way for CMOS (Complementary Metal Oxide Semiconductor) implementation of full on-chip tactile sensing systems based on POSFETs