A Compact Modular Soft Surface With Reconfigurable Shape and Stiffness

A variety of reconfigurable surface devices, utilizing large numbers of actuated physical pixels to produce discretized 3D contours, have been developed for different purposes in research and industry. The difficulty of integrating many actuators in close configuration has limited the DoF and resolution and performance of existing devices. Utilizing vacuum power and soft material actuators, we have developed a soft reconfigurable surface (SRS) with multi-modal control and performance capabilities. The SRS is comprised of a square grid array of linear vacuum-powered soft pneumatic actuators (linear V-SPAs), built into plug-and-play modules which enable the arrangement, consolidation, and control of many DoF. In addition to the practical benefits of system integration, this architecture facilitates the construction of customized assemblies with an overall compact form factor. A series of experiments is performed to illustrate and validate the versatility of the SRS for achieving diverse tasks including force controlled modulation of interface pressure through integrated sensors, lateral manipulation of a variety of objects, static and dynamic shape and pattern generation for haptic interaction, and variable surface stiffness tuning. This SRS concept is scalable, space efficient and features diverse functional potential. This will extend the utility and accessibility of tangible robotic interfaces for future applications from industrial to home and personal use

An Abdominal Phantom with Tunable Stiffness Nodules and Force Sensing Capability for Palpation Training

Robotic phantoms enable advanced physical examination training before using human patients. In this paper, we present an abdominal phantom for palpation training with controllable stiffness liver nodules that can also sense palpation forces. The coupled sensing and actuation approach is achieved by pneumatic control of positive-granular jammed nodules for tunable stiffness. Soft sensing is done using the variation of internal pressure of the nodules under external forces. This paper makes original contributions to extend the linear region of the neo-Hookean characteristic of the mechanical behavior of the nodules by 140% compared to no-jamming conditions and to propose a method using the organ level controllable nodules as sensors to estimate palpation position and force with a root-means-quare error (RMSE) of 4% and 6.5%, respectively. Compared to conventional soft sensors, the method allows the phantom to sense with no interference to the simulated physiological conditions when providing quantified feedback to trainees, and to enable training following current bare-hand examination protocols without the need to wear data gloves to collect data.This work was supported in part by the Engineering and Physical Sciences Research Council (EPSRC) MOTION grant EP/N03211X/2 and EP/N03208X/1, and EPSRC RoboPatient grant EP/T00603X/

Design and Implementation of an Interactive Surface System with Controllable Shape and Softness

「平面的で硬い」という従来のディスプレイの物理的制約は、ユーザが3次元的な形状を有するデータを扱う場合や触覚的な情報を有するデータと対話する場合に様々な制限を与えている. また, 平面的なディスプレイ上で複雑な立体形状を閲覧・モデリングするためには, 頻繁な視点移動や複雑な頂点操作等を伴うGUI操作が必要である. このような問題を解決するため, 砂, 粘土のような非平面的・柔軟な素材をサーフェスに取り入れて, 従来のディスプレイにできない異なるインタラクションを可能にした研究が行われていたが, 一つのデバイスで異なる物理性質を表現できるディスプレイはあまり研究されていない.本研究は細かなパーティクルと気圧操作による硬さ制御技術に着目し, 硬度可変ディスプレイの実装を行った. 硬さ制御によって, 軟らかいときに形状の変形や, 用途に応じて形状を維持することもできる.このディスプレイの可能性を探るため, 硬さ制御を利用したモデリングアプリケーションを開発した. このアプリケーションでは, モデリング操作に応じて, 適切な硬さを選択する事ができ, モデルが完成した時にディスプレイを硬化し形状を維持させることが可能である.また, 深度カメラを用いることで, タッチ入力による彩色が可能になり, 作成したモデルをスキャンし, CADデータとして保存することもできる. さらに, 3Dプリンターで出力することも可能にした.このシステムは、従来のモデリング操作をより直感的する事ができるが, システム単独で形状を生成することができない. そこで, 本研究では粒子運搬技術を用いて, ディスプレイの形状アクチュエーション手法も提案する. この手法では, モデルの大まかな形状を生成することで, ユーザは形状の細部を自由にカスタマイズすることができる. この手法は, 硬さ制御技術と同じくパーティクルと空気アクチュエーションを用いているため, 低コストかつシンプルなシステムで実現することができる.電気通信大学201

A Review of Pneumatic Actuators Used for the Design of Medical Simulators and Medical Tools

International audienc

Designing LMPA-Based Smart Materials for Soft Robotics Applications

This doctoral research, Designing LMPA (Low Melting Point Alloy) Based Smart Materials for Soft Robotics Applications, includes the following topics: (1) Introduction; (2) Robust Bicontinuous Metal-Elastomer Foam Composites with Highly Tunable Mechanical Stiffness; (3) Actively Morphing Drone Wing Design Enabled by Smart Materials for Green Unmanned Aerial Vehicles; (4) Dynamically Tunable Friction via Subsurface Stiffness Modulation; (5) LMPA Wool Sponge Based Smart Materials with Tunable Electrical Conductivity and Tunable Mechanical Stiffness for Soft Robotics; and (6) Contributions and Future Work.Soft robots are developed to interact safely with environments. Smart composites with tunable properties have found use in many soft robotics applications including robotic manipulators, locomotors, and haptics. The purpose of this work is to develop new smart materials with tunable properties (most importantly, mechanical stiffness) upon external stimuli, and integrate these novel smart materials in relevant soft robots. Stiffness tunable composites developed in previous studies have many drawbacks. For example, there is not enough stiffness change, or they are not robust enough. Here, we explore soft robotic mechanisms integrating stiffness tunable materials and innovate smart materials as needed to develop better versions of such soft robotic mechanisms. First, we develop a bicontinuous metal-elastomer foam composites with highly tunable mechanical stiffness. Second, we design and fabricate an actively morphing drone wing enabled by this smart composite, which is used as smart joints in the drone wing. Third, we explore composite pad-like structures with dynamically tunable friction achieved via subsurface stiffness modulation (SSM). We demonstrate that when these composite structures are properly integrated into soft crawling robots, the differences in friction of the two ends of these robots through SSM can be used to generate translational locomotion for untethered crawling robots. Also, we further develop a new class of smart composite based on LMPA wool sponge with tunable electrical conductivity and tunable stiffness for soft robotics applications. The implications of these studies on novel smart materials design are also discussed

Soft actuation and sensing towards robot-assisted facial rehabilitation

Continuing research efforts in robot-assisted rehabilitation demand more adaptable and inherently soft wearable devices. A wearable rehabilitative device is required to follow the motion of the body and to provide assistive or corrective motions to restore natural movements. Providing the required level of fluidity in wearable devices becomes a challenge for rehabilitation of more sensitive and fragile body parts, such as the face. To address this challenge, we propose a soft actuation method based on a tendon-driven robotic origami (robogami) and a soft sensing method based on a strain gauge with customized stretchable mesh design. The proposed actuation and sensing methods are compatible with the requirements in a facial rehabilitative device. The conformity of robogamis originates from their multiple and redundant degrees of freedom and the controllability of the joint stiffness, which is provided by adjusting the elasticity modulus of an embedded shape memory polymer (SMP) layer. The reconfiguration of the robogami and the trajectory and directional compliance of its end-effector are controlled by modulating the temperatures, hence the stiffness, of the SMP layers. Here we demonstrate this correlation using simulation and experimental results. In this paper, we introduce a thin and highly compliant sensing method for measuring facial movements with a minimal effect on the natural motions. The measurements of the sensors on the healthy side can be used to calculate the required tendon displacement for replicating the natural motion on the paralyzed side of the face in patients suffering from facial palsy

Stiffness Control With Shape Memory Polymer in Underactuated Robotic Origamis

Underactuated systems offer compact design with easy actuation and control but at the cost of limited stable con- figurations and reduced dexterity compared to the directly driven and fully actuated systems. Here, we propose a compact origamibased design in which we can modulate the material stiffness of the joints and thereby control the stable configurations and the overall stiffness in an underactuated robot. The robotic origami, robogami, design uses multiple functional layers in nominally twodimensional robots to achieve the desired functionality. To control the stiffness of the structure, we adjust the elastic modulus of a shape memory polymer using an embedded customized stretchable heater. We study the actuation of a robogami finger with three joints and determine its stable configurations and contact forces at different stiffness settings. We monitor the configuration of the finger using feedback from customized curvature sensors embedded in each joint. A scaled down version of the design is used in a two-fingered gripper and different grasp modes are achieved by activating different sets of joints

Modular soft pneumatic actuator system design for compliance matching

The future of robotics is personal. Never before has technology been as pervasive as it is today, with advanced mobile electronics hardware and multi-level network connectivity pushing âsmartâ devices deeper into our daily lives through home automation systems, virtual assistants, and wearable activity monitoring. As the suite of personal technology around us continues to grow in this way, augmenting and offloading the burden of routine activities of daily living, the notion that this trend will extend to robotics seems inevitable. Transitioning robots from their current principal domain of industrial factory settings to domestic, workplace, or public environments is not simply a matter of relocation or reprogramming, however. The key differences between âtraditionalâ types of robots and those which would best serve personal, proximal, human interactive applications demand a new approach to their design. Chief among these are requirements for safety, adaptability, reliability, reconfigurability, and to a more practical extent, usability. These properties frame the context and objectives of my thesis work, which seeks to provide solutions and answers to not only how these features might be achieved in personal robotic systems, but as well what benefits they can afford. I approach the investigation of these questions from a perspective of compliance matching of hardware systems to their applications, by providing methods to achieve mechanical attributes complimentary to their environment and end-use. These features are fundamental to the burgeoning field of Soft Robotics, wherein flexible, compliant materials are used as the basis for the structure, actuation, sensing, and control of complete robotic systems. Combined with pressurized air as a power source, soft pneumatic actuator (SPA) based systems offers new and novel methods of exploiting the intrinsic compliance of soft material components in robotic systems. While this strategy seems to answer many of the needs for human-safe robotic applications, it also brings new questions and challenges: What are the needs and applications personal robots may best serve? Are soft pneumatic actuators capable of these tasks, or âusefulâ work output and performance? How can SPA based systems be applied to provide complex functionality needed for operation in diverse, real-world environments? What are the theoretical and practical challenges in implementing scalable, multiple degrees of freedom systems, and how can they be overcome? I present solutions to these problems in my thesis work, elucidated through scientific design, testing and evaluation of robotic prototypes which leverage and demonstrate three key features: 1) Intrinsic compliance: provided by passive elastic and flexible component material properties, 2) Extrinsic compliance: rendered through high number of independent, controllable degrees of freedom, and 3) Complementary design: exhibited by modular, plug and play architectures which combine both attributes to achieve compliant systems. Through these core projects and others listed below I have been engaged in soft robotic technology, its application, and solutions to the challenges which are critical to providing a path forward within the soft robotics field, as well as for the future of personal robotics as a whole toward creating a better society