Fluidic Fabric Muscle Sheets for Wearable and Soft Robotics

Abstract

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 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.forces upon, or generate shape changes in complex or compliant structures. 1-3 Wearable soft robotic devices interfaced with the human body may prove valuable for rehabilitation, movement assistance, or virtual reality. [4][5][6] Soft actuators are also of interest for controlling motion in distributed or deformable structures. They can be used for tasks such as grasping, terrestrial locomotion, surgery, or underwater operation. 7-9 Such applications span systems of greatly varying length scales, ranging from millimeter-scale biomedical robots to large, deployable structures. 10,11 Biological systems provide a rich source of information to guide the design of soft robots. 12 The motile capabilities of animals are enabled by composite systems of muscle, connective, and other tissues. The forces and motions they can produce depend on the properties of individual muscle fibers, the arrangement of fibers, and the muscle morphology and attachments. Muscle morphologies vary widely. There are fusiform shapes like the human biceps brachii, that produce large-amplitude motion. There are also fan shapes, such as the pectoralis major, that yield larger forces, sphincter morphologies that contract, and layered muscle sheets, like the transverse abdominis (Fig. 1A), that compress or transfer forces around the torso. 13 The great variety of biologica...

Design, Modeling, Control, and Application of Everting Vine Robots

“…Inverse pneumatic artificial muscles (IPAMs), first demonstrated in Hawkes et al (2016) and used in Zhu et al (2020) to create fabric muscle sheets, are constructed using a cylindrical rubber bladder enclosed by a strain limiting layer. This layer forces the bladder to expand lengthwise, not radially, when pressurized.…”

Bio‐Inspired Conformable and Helical Soft Fabric Gripper with Variable Stiffness and Touch Sensing

“…There are a wide variety of options in the combination of fabrics and stitches to create the fabric sleeve for the helical gripper. [57] To induce bending, the fabric sleeve should be stretched on one side while the other side is strain limited. Non-stretchable fabrics, such as cotton weaves, are suitable material for this purpose while the extending side can be made of either non-stretchable fabrics with wrinkles or stretchable fabrics.…”

Advanced Intelligent Systems for Surgical Robotics

“…Flexible fluidic actuation is also used for medical applications. [182,183] This type of actuation converts the pressure from an external fluid source (hydraulic or pneumatic source) into elongation or bending motion based on the deformation of elastic materials, which subsequently actuates the robotic joint or flexible bending part. [184] Fluidic actuation can bend, stretch, Figure 10.…”