Haptic Edge Detection Through Shear

Most tactile sensors are based on the assumption that touch depends on measuring pressure. However, the pressure distribution at the surface of a tactile sensor cannot be acquired directly and must be inferred from the deformation field induced by the touched object in the sensor medium. Currently, there is no consensus as to which components of strain are most informative for tactile sensing. Here, we propose that shape-related tactile information is more suitably recovered from shear strain than normal strain. Based on a contact mechanics analysis, we demonstrate that the elastic behavior of a haptic probe provides a robust edge detection mechanism when shear strain is sensed. We used a jamming-based robot gripper as a tactile sensor to empirically validate that shear strain processing gives accurate edge information that is invariant to changes in pressure, as predicted by the contact mechanics study. This result has implications for the design of effective tactile sensors as well as for the understanding of the early somatosensory processing in mammals

触覚フィードバックを用いた体性感覚の操作

人間が自らの肉体に対して持つ興味は大きい．多くの人間は体力的・知能的・美的な面で他の人間よりも優れた肉体を欲すると考えられ，また様々な特殊な体を持つ空想上のキャラクターに憧れ人間とは異なる構造の身体に興味を持つ物も多いであろう．だが身体機能の向上のためには通常長期間の継続した訓練を必要とし，人間とは異なる身体への変身は不可能であるといえる．科学技術の発展に伴い肉体形状および運動機能への物理的な介入方法が広まりつつあるが，未だに身体的リスクと金銭的コストが高く，複雑な装置を必要とするため誰もが気軽に利用できるものではない．このような背景から本研究では，人間の肉体そのものに介入するのではなく，肉体が生成する感覚である体性感覚を肉体外部から操作することで肉体の主観的特性を操作することを目標とする．主に身体表面の感覚を刺激するアクチュエータとして広く使われているボイスコイル型振動子は，様々な触感の呈示を簡便なセットアップで実現できる．したがってこれを身体運動に同期させて駆動する振動フィードバックシステムを開発し，運動に伴って発生する身体内部の感覚を操作することを試みる．体性感覚の操作に関する本研究は2 つの戦略によって構成される．一つは体性感覚の「増強」である．これは自己身体運動を把握する能力を高め，より鮮明に，あるいは詳細に運動状態を知覚させる量的な操作である．一方で，もう一つの戦略は体性感覚の質的な操作である「変調」である．これは身体自体の硬さや重さといった特性を変化させることであり，結果として身体を構成する材質・構造を主観的に変調することになる．これら2 つの戦略に沿った具体的な手法を，体性感覚の増強に関して2 件，変調に関しても2件設計した．体性感覚の増強に関しては，第一にロータリスイッチの回転に伴うカチカチとした触覚・力覚フィードバック「カチカチ感」に着目した．これを肘関節に付与して運動時の体性感覚を鮮明化し，腕立て伏せ姿勢の教示を試みた（第3 章）．第二に，自動車運転におけるアクセルペダルの操作を補助するため，ペダルの角度が一定値変化する度に瞬間的なクリック振動を呈示することで，ペダル角度の把握能力向上および操作性向上を試みた（第4 章）．体性感覚の変調に関しては，第一に様々な材質の衝突振動を再現する減衰正弦波モデルに着目し，これを身体運動に同期させて呈示することで身体材質感の変調を試みた（第5 章）．これによりロボットやゴム人間といった特殊なキャラクターの体性感覚の再現を目指した．第二に，ロボットキャラクターのみに着目し，実際のロボットに生じる振動加速度を記録・モデリング・再生する手法によりロボットの内部構造に起因する体性感覚まで再現することを試みた（第6 章）．またロボット感体験の総合的なリアリティ向上のため高品質な視覚・聴覚刺激を組み合わせたバーチャルリアリティゲームを開発した．また体性感覚の操作をより広範囲で行うため，既存の触覚ディスプレイの問題点を考察し，身体広範囲に均等な触覚刺激を呈示する触覚ディスプレイを開発した（第7 章）．最後に本研究全体のまとめと結論を述べ，今後の展望を示す（第8 章）．電気通信大学201

Snake Robots for Surgical Applications: A Review

Although substantial advancements have been achieved in robot-assisted surgery, the blueprint to existing snake robotics predominantly focuses on the preliminary structural design, control, and human–robot interfaces, with features which have not been particularly explored in the literature. This paper aims to conduct a review of planning and operation concepts of hyper-redundant serpentine robots for surgical use, as well as any future challenges and solutions for better manipulation. Current researchers in the field of the manufacture and navigation of snake robots have faced issues, such as a low dexterity of the end-effectors around delicate organs, state estimation and the lack of depth perception on two-dimensional screens. A wide range of robots have been analysed, such as the i2Snake robot, inspiring the use of force and position feedback, visual servoing and augmented reality (AR). We present the types of actuation methods, robot kinematics, dynamics, sensing, and prospects of AR integration in snake robots, whilst addressing their shortcomings to facilitate the surgeon’s task. For a smoother gait control, validation and optimization algorithms such as deep learning databases are examined to mitigate redundancy in module linkage backlash and accidental self-collision. In essence, we aim to provide an outlook on robot configurations during motion by enhancing their material compositions within anatomical biocompatibility standards

Layered Approaches - Woven eTextile Explorations Through Applied Textile Thinking

Woven structures form the most common type of textile in our everyday life. Their potential for eTextile development, ranging from component integration to entirely woven user interfaces, has invited researchers from various fields to explore how weaving can expand the interactive capabilities of textile surfaces around us. However, eTextile literature typically considers weaving as a method of constructing, and rarely acknowledges the reflective nature of weaving, and the insights related to thinking associated with textile design practices, that is, textile thinking, are often sparingly described. The overarching research question in this thesis is how can weaving be used to explore new concepts and design opportunities for eTextiles, and it is examined through five academic publications. The exploration of textile thinking was carried out through a practice-based design research approach on technical woven eTextile development. The primary methods for data collection were the woven textile design practices and semi-structured interviews, complemented by reviewing grey and academic literature related to woven eTextiles. The first study investigated how the orthogonal yarn architecture of woven structures enables the integration of electrical circuitry. The second study examined how electrically functional structures and sensorial properties of a textile surface can be designed in parallel to form a user interface for an interactive textile object through a case of an interactive hand puppet. The third study included an exploratory weaving process to map the possibilities of multi-layer weaves for woven eTextile development through accumulative design experimentation. The fourth study reviewed eTextile literature through the lens of woven textile design to understand how weaving has been used in eTextile research across different disciplines. The review identified woven structures whose potential for eTextile development has remained uncharted. The fifth study examined the role of weaving within an interdisciplinary eTextile material development process by focusing on the experiences of the researchers working on a project developing yarn-like actuators for shape-changing interactive textiles. The practice-based approach grounded on textile thinking was found to be well-suited for mapping the design space of woven eTextiles to discover new research opportunities. The approach enables accessing methods based on textile design and construction skills and conducting the investigation through the possibilities of weaving. As a core contribution, this thesis proposes a model for approaching woven eTextiles as electrically functional material systems, in which woven textiles' structural hierarchy collides with circuit design principles

Role of Bearings in New Generation Automotive Vehicles: Powertrain

Modern Automobile powertrain’s technology is transforming to enable “connected, autonomous, shared and electric” (CASE). Modern automobiles are targeting to achieve the maximum vehicle uptime, utilization, and better total cost of ownership (TCO). Bearing is a vital component (sub-system) to achieve modern automobile’s performance targets. Bearings plays important role of performance enhancement of all the rotating parts in systems by carrying the load and facilitating transfer of torque. Bearings achieve its performance via correct selection of materials, manufacturing technologies, design optimized geometries, sealing, lubrication in addition to application specific features. In modern automobile passenger comfort is key consideration and role of bearing is critical to achieve lower system noise. This chapter focuses on building awareness of the bearing technical requirements for different aggregates and means to achieve the requirements for modern automobiles. Summary of 11,300 patent’s titles and customer voice analysis suggest the bearing development focus areas direction which are covered in this chapter. This chapter also introduces bearing technology research focus areas like reliability improvement, power-dense solutions, integrated functions, friction optimization, sealing/lubrication solutions, adoption of sensors, and also special application-specific eMotors bearings. Modern electronic technologies integrated with bearings are performing the critical role of powertrain health monitoring in the vehicle. However, bearings are having furthermore potential to contribute and enhance the performance of modern automobiles in near future

New generation of interactive platforms based on novel printed smart materials

Programa doutoral em Engenharia Eletrónica e de Computadores (área de Instrumentação e Microssistemas Eletrónicos)The last decade was marked by the computer-paradigm changing with other digital devices suddenly becoming available to the general public, such as tablets and smartphones. A shift in perspective from computer to materials as the centerpiece of digital interaction is leading to a diversification of interaction contexts, objects and applications, recurring to intuitive commands and dynamic content that can proportionate more interesting and satisfying experiences. In parallel, polymer-based sensors and actuators, and their integration in different substrates or devices is an area of increasing scientific and technological interest, which current state of the art starts to permit the use of smart sensors and actuators embodied within the objects seamlessly. Electronics is no longer a rigid board with plenty of chips. New technological advances and perspectives now turned into printed electronics in polymers, textiles or paper. We are assisting to the actual scaling down of computational power into everyday use objects, a fusion of the computer with the material. Interactivity is being transposed to objects erstwhile inanimate. In this work, strain and deformation sensors and actuators were developed recurring to functional polymer composites with metallic and carbonaceous nanoparticles (NPs) inks, leading to capacitive, piezoresistive and piezoelectric effects, envisioning the creation of tangible user interfaces (TUIs). Based on smart polymer substrates such as polyvinylidene fluoride (PVDF) or polyethylene terephthalate (PET), among others, prototypes were prepared using piezoelectric and dielectric technologies. Piezoresistive prototypes were prepared with resistive inks and restive functional polymers. Materials were printed by screen printing, inkjet printing and doctor blade coating. Finally, a case study of the integration of the different materials and technologies developed is presented in a book-form factor.A última década foi marcada por uma alteração do paradigma de computador pelo súbito aparecimento dos tablets e smartphones para o público geral. A alteração de perspetiva do computador para os materiais como parte central de interação digital levou a uma diversificação dos contextos de interação, objetos e aplicações, recorrendo a comandos intuitivos e conteúdos dinâmicos capazes de tornarem a experiência mais interessante e satisfatória. Em simultâneo, sensores e atuadores de base polimérica, e a sua integração em diferentes substratos ou dispositivos é uma área de crescente interesse científico e tecnológico, e o atual estado da arte começa a permitir o uso de sensores e atuadores inteligentes perfeitamente integrados nos objetos. Eletrónica já não é sinónimo de placas rígidas cheias de componentes. Novas perspetivas e avanços tecnológicos transformaram-se em eletrónica impressa em polímeros, têxteis ou papel. Neste momento estamos a assistir à redução da computação a objetos do dia a dia, uma fusão do computador com a matéria. A interatividade está a ser transposta para objetos outrora inanimados. Neste trabalho foram desenvolvidos atuadores e sensores e de pressão e de deformação com recurso a compostos poliméricos funcionais com tintas com nanopartículas (NPs) metálicas ou de base carbónica, recorrendo aos efeitos capacitivo, piezoresistivo e piezoelétrico, com vista à criação de interfaces de usuário tangíveis (TUIs). Usando substratos poliméricos inteligentes tais como fluoreto de polivinilideno (PVDF) ou politereftalato de etileno (PET), entre outos, foi possível a preparação de protótipos de tecnologia piezoelétrica ou dielétrica. Os protótipos de tecnologia piezoresistiva foram feitos com tintas resistivas e polímeros funcionais resistivos. Os materiais foram impressos por serigrafia, jato de tinta, impressão por aerossol e revestimento de lâmina doctor blade. Para terminar, é apresentado um caso de estudo da integração dos diferentes materiais e tecnologias desenvolvidos sob o formato de um livro.This project was supported by FCT – Fundação para a Ciência e a Tecnologia, within the doctorate grant with reference SFRH/BD/110622/2015, by POCH – Programa Operacional Capital Humano, and by EU – European Union

Tactile displays, design and evaluation

Fritschi M. Tactile displays, design and evaluation. Bielefeld: Universität Bielefeld; 2016.This thesis presents the design and development of several tactile displays, as well as their eventual integration into a framework of tactile and kinesthetic stimulation. As a basis for the design of novel devices, an extensive survey of existing actuator principles and existing realizations of tactile displays is complemented by neurobiological and psychophysical findings. The work is structured along three main goals: First, novel actuator concepts are explored whose performance can match the challenging capabilities of human tactile perception. Second, novel kinematic concepts for experimental platforms are investigated that target an almost unknown sub-modality of tactile perception: The perception of shear force. Third, a setup for integrated tactile-kinesthetic displays is realized, and a first study on the psychophysical correlation between the tactile and the kinesthetic portion of haptic information is conducted. The developed devices proved to exceed human tactile capabilities and have already been used to learn more about the human tactile sense

Micro/nanoscale magnetic robots for biomedical applications

Magnetic small-scale robots are devices of great potential for the biomedical field because of the several benefits of this method of actuation. Recent work on the development of these devices has seen tremendous innovation and refinement toward ​improved performance for potential clinical applications. This review briefly details recent advancements in small-scale robots used for biomedical applications, covering their design, fabrication, applications, and demonstration of ability, and identifies the gap in studies and the difficulties that have persisted in the optimization of the use of these devices. In addition, alternative biomedical applications are also suggested for some of the technologies that show potential for other functions. This study concludes that although the field of small-scale robot research is highly innovative ​there is need for more concerted efforts to improve functionality and reliability of these devices particularly in clinical applications. Finally, further suggestions are made toward ​the achievement of commercialization for these devices

Biology and bioinspiration of soft robotics : actuation, sensing, and system integration

Organisms in nature grow with senses, nervous, and actuation systems coordinated in ingenious ways to sustain metabolism and other essential life activities. The understanding of biological structures and functions guide the construction of soft robotics with unprecedented performances. However, despite the progress in soft robotics, there still remains a big gap between man-made soft robotics and natural lives in terms of autonomy, adaptability, self-repair, durability, energy efficiency, etc. Here, the actuation and sensing strategies in the natural biological world are summarized along with their man-made counterparts applied in soft robotics. The development trends of bioinspired soft robotics toward closed loop and embodiment are proposed. Challenges for obtaining autonomous soft robotics similar to natural organisms are outlined to provide a perspective in this field. [Abstract copyright: © 2021.