Design and Development of a Soft Robotic Gripper for Fabric Material Handling

Fabric and textile materials are widely used in many industrial applications, especially in automotive, aviation and consumer goods. Currently, there is no semi-automatic or automatic solution for rapid, effective, and reconfigurable pick and place activities for limp, air permeable flexible components in industry. The production of these light-weight flexible textile or composite fiber products highly rely on manual operations, which lead to high production costs, workplace safety issues, and process bottlenecks. As a bio-inspired novel technology, soft robotic grippers provide new opportunities for the automation of fabric handling tasks. In this research, the characteristics of fabric pick and place tasks using the clamping grippers are quantitatively investigated. Experiments on a carbon fiber fabric are performed with a collaborative robot to explore the damage, slippage, draping, and wrinkling during basic pick and place operations. Based on the experimental results, multiple soft robotic gripper configurations are developed, including a compliant glove set that can improve the performance of traditional rigid grippers, an elastomer-based soft gripper, and a linkage-based underactuated gripper. The gripper designs are analyzed and refined based on finite element simulation. Prototypes of the grippers are fabricated using a rapid tooling solution for an overmolding strategy to verify their functionality. Through the research, it is proven feasible to reliably perform flexible fabric handling operations using soft grippers with appropriate toolpath planning. Finite element simulation and additive manufacturing have shown to be useful tools during the gripper design and development procedure, and the methodologies developed and applied in this work should be expanded for more flexible material handling challenges

A Dexterous Tip-extending Robot with Variable-length Shape-locking

Soft, tip-extending "vine" robots offer a unique mode of inspection and manipulation in highly constrained environments. For practicality, it is desirable that the distal end of the robot can be manipulated freely, while the body remains stationary. However, in previous vine robots, either the shape of the body was fixed after growth with no ability to manipulate the distal end, or the whole body moved together with the tip. Here, we present a concept for shape-locking that enables a vine robot to move only its distal tip, while the body is locked in place. This is achieved using two inextensible, pressurized, tip-extending, chambers that "grow" along the sides of the robot body, preserving curvature in the section where they have been deployed. The length of the locked and free sections can be varied by controlling the extension and retraction of these chambers. We present models describing this shape-locking mechanism and workspace of the robot in both free and constrained environments. We experimentally validate these models, showing an increased dexterous workspace compared to previous vine robots. Our shape-locking concept allows improved performance for vine robots, advancing the field of soft robotics for inspection and manipulation in highly constrained environments.Comment: 7 pages,10 figures. Accepted to IEEE International Conference on Rootics and Automation (ICRA) 202

Fluidic Fabric Muscle Sheets for Wearable and Soft Robotics

Conformable robotic systems are attractive for applications in which they can be used to actuate structures with large surface areas, to provide forces through wearable garments, or to realize autonomous robotic systems. We present a new family of soft actuators that we refer to as Fluidic Fabric Muscle Sheets (FFMS). They are composite fabric structures that integrate fluidic transmissions based on arrays of elastic tubes. These sheet-like actuators can strain, squeeze, bend, and conform to hard or soft objects of arbitrary shapes or sizes, including the human body. We show how to design and fabricate FFMS actuators via facile apparel engineering methods, including computerized sewing techniques. Together, these determine the distributions of stresses and strains that can be generated by the FFMS. We present a simple mathematical model that proves effective for predicting their performance. FFMS can operate at frequencies of 5 Hertz or more, achieve engineering strains exceeding 100%, and exert forces greater than 115 times their own weight. They can be safely used in intimate contact with the human body even when delivering stresses exceeding 10$^\text{6}$ Pascals. We demonstrate their versatility for actuating a variety of bodies or structures, and in configurations that perform multi-axis actuation, including bending and shape change. As we also show, FFMS can be used to exert forces on body tissues for wearable and biomedical applications. We demonstrate several potential use cases, including a miniature steerable robot, a glove for grasp assistance, garments for applying compression to the extremities, and devices for actuating small body regions or tissues via localized skin stretch.Comment: 32 pages, 10 figure

Mechanical Self-Assembly of a Strain-Engineered Flexible Layer: Wrinkling, Rolling, and Twisting

Self-shaping of curved structures, especially those involving flexible thin layers, has attracted increasing attention because of their broad potential applications in e.g. nanoelectromechanical/micro-electromechanical systems (NEMS/MEMS), sensors, artificial skins, stretchable electronics, robotics, and drug delivery. Here, we provide an overview of recent experimental, theoretical, and computational studies on the mechanical self-assembly of strain-engineered thin layers, with an emphasis on systems in which the competition between bending and stretchingenergy gives rise to a variety ofdeformations,such as wrinkling, rolling, and twisting. We address the principle of mechanical instabilities, which is often manifested in wrinkling or multistability of strain-engineered thin layers. The principles of shape selection and transition in helical ribbons are also systematically examined. We hope that a more comprehensive understanding of the mechanical principles underlying these rich phenomena can foster the development of new techniques for manufacturing functional three- dimensional structures on demand for a broad spectrum of engineering applications.Comment: 91 pages, 35 figures, review articl

Significance of designing the filling of an open rapid sand filter when removing impurities from water

Filtration is a mechanical process of squeezing, during which the passage of liquid occurs, in this paper, specifically water, through a porous layer of material. During that flow, the impurities are retained within that layer, which is called the filter, and the water is desired quality comes out of the filtering device. The goal of this work is to demonstrate the importance of dimensioning the filter itself, so reliably that during the actual filling of the filter, almost all impurities remain in that layer. There are different types of filters, and also different dimensions for each type. Which type will be specifically used depends on several factors such as the desired quality of the water coming out of the filter, the initial state of the water (pollution) coming into the filter, the amount of water reaching the filter, the speed of the filtration process itself, etc. In this paper, the importance of dimensioning sand filters, as well as the selection of the filter filling method, is highlighted

Mechanics and applications of stretchable serpentine structures

Stretchable structures have been developed for various applications, including expandable coronary stents, deployable sensor networks and stretchable bio-mimetic and bio-integrated electronics. High-performance, stretchable electronics have to utilize high-quality and long-lasting inorganic electronic materials such as silicon, oxide dielectrics and metals, which are intrinsically stiff and often brittle. It is therefore an interdisciplinary challenge to make inorganic electronics stretchable while retaining their electronic functionality. Patterning stiff materials into serpentine-shaped wavy ribbons has become a popular strategy for fabricating stretchable inorganic electronics. However due to a lack of mechanics understanding, design of serpentine structures is still largely empirical, whether for freestanding or substrate supported serpentines. This dissertation systematically investigates the mechanics of serpentine structures with emphasis on the effects of serpentine geometry and substrate stiffness, which involves theoretical analysis, numerical simulation, and experimental validation. Our theory has successfully predicted the stretchability and stiffness of various serpentine shapes and has been applied to the optimization of serpentine designs under practical constraints. We are also the first to point out that not all geometric effects are monotonic and serpentines are not always more stretchable than linear ribbons. To manufacture high quality serpentine ribbons with high throughput and low cost, we have invented a “cut-and-paste” method to fabricate both metallic and ceramic serpentines. As a demonstration of our method, a noninvasive, tattoo-like multifunctional epidermal sensor system has been built for the measurement of electrophysiological signals, skin temperature, skin hydration, and respiratory rate. Engineering of epidermal stretchable antenna for wireless communication is also detailed and rationalized.Mechanical Engineerin

Significance of designing the filling of an open rapid sand filter when removing impurities from water

Filtration is a mechanical process of squeezing, during which the passage of liquid occurs, in this paper, specifically water, through a porous layer of material. During that flow, the impurities are retained within that layer, which is called the filter, and the water is desired quality comes out of the filtering device. The goal of this work is to demonstrate the importance of dimensioning the filter itself, so reliably that during the actual filling of the filter, almost all impurities remain in that layer. There are different types of filters, and also different dimensions for each type. Which type will be specifically used depends on several factors such as the desired quality of the water coming out of the filter, the initial state of the water (pollution) coming into the filter, the amount of water reaching the filter, the speed of the filtration process itself, etc. In this paper, the importance of dimensioning sand filters, as well as the selection of the filter filling method, is highlighted

Design of a novel long-range inflatable robotic arm: Manufacturing and numerical evaluation of the joints and actuation

The aim of this paper is to present the design of a new long-range robotic arm based on an inflatable structure. Inflatable robotics has potential for improved large payload-to-weight ratios, safe collision, and inspection in areas inaccessible to human beings as in nuclear plants. The robot presented here is intended to operate inspection or maintenance missions in critical installation taking care to not collide with its environment. It is made with innovative inflatable joints and an original actuation system. Prototypes of this inflatable manipulator were constructed using two different manufacturing procedures. Using LS-DYNA nonlinear dynamic finite element modeling we have numerically analyzed the specific geometry and dynamical behavior of the resulting joints. The simulations have given insight into understanding the joint bending process and have revealed guidance for optimizing the conception