Optically controlled grasping-slipping robot moving on tubular surfaces

Stimuli-responsive polymers provide unmatched opportunities for remotely controlled soft robots navigating in complex environments. Many of the responsive-material-based soft robots can walk on open surfaces, with movement directionality dictated by the friction anisotropy at the robot-substrate interface. Translocation in one-dimensional space such as on a tubular surface is much more challenging due to the lack of efficient friction control strategies. Such strategies could in long term provide novel application prospects in, e.g. overhaul at high altitudes and robotic operation within confined environments. In this work, we realize a liquid-crystal-elastomer-based soft robot that can move on a tubular surface through optical control over the grasping force exerted on the surface. Photoactuation allows for remotely switched gripping and friction control which, together with cyclic body deformation, enables light-fueled climbing on tubular surfaces of glass, wood, metal, and plastic with various cross-sections. We demonstrate vertical climbing, moving obstacles along the path, and load-carrying ability (at least 3 × body weight). We believe our design offer new prospects for wirelessly driven soft micro-robotics in confined spacing.publishedVersionPeer reviewe

미세돌기 표면용 그리퍼를 위한 미세 핀 배열의 내구성 향상

학위논문 (석사)-- 서울대학교 대학원 : 기계항공공학부 우주항공공학전공, 2016. 2. 주종남.In this study, durability of micro-pin array fabricated using nanosecond pulsed laser beam machining is improved for wall attachment mechanism of a climbing robot. Fabrication of micro-pin array using nanosecond pulsed laser beam machining was previously studied for simply clinging on the wall. However, due to low durability of pins, tips of pins were broken after multiple uses so the broken pins were not able to get interlocked. This study suggests a new method to increase durability of pin array for continuous use while increasing the maximum interlocking force of pins. Electrochemical etching process was used for durability improvement and interlocking force increment of pin array was gained through controlling line spacing and tip radius. Maximum interlocking force of pin has increased from 176.48 mN/mm2 to 205.32 mN/mm2, and 205.32 mN/mm2 of constant and steady interlocking force could be achieved after multiple uses without damaging tip of micro-pin array.Chapter 1. Introduction 1 1.1. Study Background 1 1.2. Purpose of Research 4 Chapter 2. Methods 6 2.1. Fabrication of micro-pin array 6 2.2. Electrochemical etching 8 2.3. Interlocking force measurement system 10 Chapter 3. Results 16 3.1. Fabrication of micro-pin array 16 3.2. Electrochemical etching and Energy Dispersive Spectro scopy 19 3.3. Interlocking force test 25 Chapter 4. Discussions 27 4.1. Analysis on tip break of micro-pin array 27 4.2. Feasibility of micro-pin array on gripper 29 Chapter 5. Conclusions 33 5.1. Conclusions 33 References 35 국문초록 38Maste

Analysis of biomimetics in the application of robotic locomotion with a focus on structures, materials and dynamics

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.Cataloged from PDF version of thesis.Includes bibliographical references (p. 61-62).Biomimetics is the study and analysis of natural systems to inform engineering design and technology development. Through interdisciplinary research and analysis of natural phenomena, engineers are able to gain valuable insight to drive efficient and robust innovation. A critical understanding of nature's design constraints is necessary to effectively create an optimized bio-inspired design. A literature review of bio-inspired design is conducted with a focus on structures, dynamics and materials in the context of robotic locomotion. The biomimetic process in the read literature is analyzed for procedure and accomplishment. A generalized method of biomimetics is presented, based on the studied work. It is concluded that successful biomimetics requires four key elements: (1) a clear understanding of the natural system, gained through depth of biological study, (2) the development of a simplified model that encompasses the core elements of the natural system, (3) the design of a synthetic system that meets the model's specifications, and (4) engineering optimization to improve the final design.by Ari Parsons Miller.S.B

Advanced Mobile Robotics: Volume 3

Mobile robotics is a challenging field with great potential. It covers disciplines including electrical engineering, mechanical engineering, computer science, cognitive science, and social science. It is essential to the design of automated robots, in combination with artificial intelligence, vision, and sensor technologies. Mobile robots are widely used for surveillance, guidance, transportation and entertainment tasks, as well as medical applications. This Special Issue intends to concentrate on recent developments concerning mobile robots and the research surrounding them to enhance studies on the fundamental problems observed in the robots. Various multidisciplinary approaches and integrative contributions including navigation, learning and adaptation, networked system, biologically inspired robots and cognitive methods are welcome contributions to this Special Issue, both from a research and an application perspective

Bio-Inspired Robotics

Modern robotic technologies have enabled robots to operate in a variety of unstructured and dynamically-changing environments, in addition to traditional structured environments. Robots have, thus, become an important element in our everyday lives. One key approach to develop such intelligent and autonomous robots is to draw inspiration from biological systems. Biological structure, mechanisms, and underlying principles have the potential to provide new ideas to support the improvement of conventional robotic designs and control. Such biological principles usually originate from animal or even plant models, for robots, which can sense, think, walk, swim, crawl, jump or even fly. Thus, it is believed that these bio-inspired methods are becoming increasingly important in the face of complex applications. Bio-inspired robotics is leading to the study of innovative structures and computing with sensory–motor coordination and learning to achieve intelligence, flexibility, stability, and adaptation for emergent robotic applications, such as manipulation, learning, and control. This Special Issue invites original papers of innovative ideas and concepts, new discoveries and improvements, and novel applications and business models relevant to the selected topics of ``Bio-Inspired Robotics''. Bio-Inspired Robotics is a broad topic and an ongoing expanding field. This Special Issue collates 30 papers that address some of the important challenges and opportunities in this broad and expanding field

Space-Capable Long and Thin Continuum Robotic Cable

Design of continuum robots, i.e. robots with continuous backbones, has been an active area of research in robotics for minimally invasive surgery, search and rescue, object manipulation, etc. Along the same lines, NASA developed Tendril , the first long and thin continuum robot of its kind, intended for in-space inspection applications. The thesis starts with describing and discussing the key disadvantages of the current state of the art mechanical design of Tendril\u27\u27 producing undesirable effects during operation. It then includes the design specifics of a novel concept for construction of a next generation long and thin, space-cable, multi-section, continuum cable-like robot, with a modified mechanical design for better performance. The new design possesses key features including controllable bending along its entire length, local compression and a compact actuation package. This new design is detailed in two versions. The first is a planar variant (suited for a 2D workspace), explaining the principle which allows the cable robot to achieve the above mentioned features. It is followed by a refined spatial version (suited for 3D workspace), where the functional characteristics are achieved within the desired aspect ratio of thin (less than 1 cm diameter) and relatively longer length (more than 100 cm) of the robotic cable. A new forward kinematic model is then developed extending the established models for constant-curvature continuum robots, to account for the new design feature of controllable compression (in the hardware) and is validated by performing experiments with the robot in (2D) planar and (3D) spatial scenarios. This new model is found to be effective as a baseline to predict the performance of such a long and thin continuum cable\u27\u27 robot

Climbing and Walking Robots

With the advancement of technology, new exciting approaches enable us to render mobile robotic systems more versatile, robust and cost-efficient. Some researchers combine climbing and walking techniques with a modular approach, a reconfigurable approach, or a swarm approach to realize novel prototypes as flexible mobile robotic platforms featuring all necessary locomotion capabilities. The purpose of this book is to provide an overview of the latest wide-range achievements in climbing and walking robotic technology to researchers, scientists, and engineers throughout the world. Different aspects including control simulation, locomotion realization, methodology, and system integration are presented from the scientific and from the technical point of view. This book consists of two main parts, one dealing with walking robots, the second with climbing robots. The content is also grouped by theoretical research and applicative realization. Every chapter offers a considerable amount of interesting and useful information

Improving Scalability of Evolutionary Robotics with Reformulation

Creating systems that can operate autonomously in complex environments is a challenge for contemporary engineering techniques. Automatic design methods offer a promising alternative, but so far they have not been able to produce agents that outperform manual designs. One such method is evolutionary robotics. It has been shown to be a robust and versatile tool for designing robots to perform simple tasks, but more challenging tasks at present remain out of reach of the method. In this thesis I discuss and attack some problems underlying the scalability issues associated with the method. I present a new technique for evolving modular networks. I show that the performance of modularity-biased evolution depends heavily on the morphology of the robot’s body and present a new method for co-evolving morphology and modular control. To be able to reason about the new technique I develop reformulation framework: a general way to describe and reason about metaoptimization approaches. Within this framework I describe a new heuristic for developing metaoptimization approaches that is based on the technique for co-evolving morphology and modularity. I validate the framework by applying it to a practical task of zero-g autonomous assembly of structures with a fleet of small robots. Although this work focuses on the evolutionary robotics, methods and approaches developed within it can be applied to optimization problems in any domain

Snake and Snake Robot Locomotion in Complex, 3-D Terrain

Snakes are able to traverse almost all types of environments by bending their elongate bodies in three dimensions to interact with the terrain. Similarly, a snake robot is a promising platform to perform critical tasks in various environments. Understanding how 3-D body bending effectively interacts with the terrain for propulsion and stability can not only inform how snakes move through natural environments, but also inspire snake robots to achieve similar performance to facilitate humans. How snakes and snake robots move on flat surfaces has been understood relatively well in previous studies. However, such ideal terrain is rare in natural environments and little was understood about how to generate propulsion and maintain stability when large height variations occur, except for some qualitative descriptions of arboreal snake locomotion and a few robots using geometric planning. To bridge this knowledge gap, in this dissertation research we integrated animal experiments and robotic studies in three representative environments: a large smooth step, an uneven arena of blocks of large height variation, and large bumps. We discovered that vertical body bending induces stability challenges but can generate large propulsion. When traversing a large smooth step, a snake robot is challenged by roll instability that increases with larger vertical body bending because of a higher center of mass. The instability can be reduced by body compliance that statistically increases surface contact. Despite the stability challenge, vertical body bending can potentially allow snakes to push against terrain for propulsion similar to lateral body bending, as demonstrated by corn snakes traversing an uneven arena. This ability to generate large propulsion was confirmed on a robot if body-terrain contact is well maintained. Contact feedback control can help the strategy accommodate perturbations such as novel terrain geometry or excessive external forces by helping the body regain lost contact. Our findings provide insights into how snakes and snake robots can use vertical body bending for efficient and versatile traversal of the three-dimensional world while maintaining stability

Micropillars for Friction Modulation at Tissue-Device Interfaces

Micropillars, microscale surface textures, can substantially influence friction properties of material interfaces. Soft micropillars have utility in compliant applications like medical devices, wearables, or robotic locomotion. However, little is known about the friction properties of or mechanisms behind soft micropillars contacting soft tissue or tissue-like substrates. In this thesis, I focus on this type of soft-on-soft micropillar friction. Chapter 1 reviews micropillars morphologies that modify the contact properties of adhesion and friction, mechanistic studies of contact, and micropillar applications. In Chapters 2-4, I outline three aims, beginning each with a more in-depth introduction. In Chapter 2, I add micropillars to enteroscopy balloons, determining that balloons textured with micropillars have superior anchoring performance on tissue compared to smooth balloons. In Chapter 3, I investigate the underlying friction mechanics behind the balloon’s soft, stretchable micropillars. I experimentally determine coefficients of friction between strained soft micropillars and a soft substrate using a custom traction measurement platform in wet and dry environments. I develop finite element models to describe this behavior, finding that micropillar spacing, shape, and contact area contribute to friction. In Chapter 4, I investigate friction of asymmetric textures. I fabricate slanted micropillars. I experimentally determine texture stiffness and lubrication affects magnitude and direction of differential friction. I develop finite element models that indicate the feature-substrate interface changes as features change stiffness. Overall, in this work I expand the field of micropillar mechanics and translational research on related medical devices. This will provide a framework for additional research into understanding how micropillars achieve their remarkable properties and how to tune interfaces for optimized contact