Abstract:
A mechanically programmed actuator includes at least one soft actuator body configured to bend, linearly extend, contract, twist, or combinations thereof when actuated without constraint; an activation mechanism (e.g., a fluid pump) configured to actuate the soft actuator body; and at least one sleeve wrapped around part of the soft actuator body and configured to constrain the soft actuator body inside the sleeve when actuated and to cause the soft actuator body to deform where not covered by the sleeve.

Description:
GOVERNMENT SUPPORT 
       [0001]    This invention was made with government support under Grant No. W911NF-11-1-0094 awarded by the Defense Advanced Research Projects Agency. The United States Government has certain rights in the invention. 
     
    
     BACKGROUND 
       [0002]    Soft actuators offer several desirable features not found in rigid mechanical systems including the ability to embed complex motions into a monolithic structure, and inherent compliance due to the elastomeric materials and pressurized fluids. Computer-aided drafting (CAD) programs and three-dimensional (3D) printers allow relatively fast iteration of mold designs for actuator fabrication (on the order of days); these approaches, however, may not allow for “on-the-fly” modification of a soft actuator&#39;s output motions, connection interfaces, and surface properties. This capacity is advantageous where immediate customization is needed, such as on the production floor for robotic manipulation or rehabilitation, where patient needs vary. 
       SUMMARY 
       [0003]    Mechanically programmed soft actuators and methods for their fabrication and use are described herein. Various embodiments of the apparatus and methods may include some or all of the elements, features and steps described below. 
         [0004]    A mechanically programmed soft actuator includes at least one soft actuator body where a least a portion of it is configured to bend, linearly extend, contract, twist or combinations thereof when actuated without constraint; an activation mechanism (e.g., a fluid pump) configured to actuate the soft actuator body; and at least one conforming sleeve wrapped around part of the soft actuator body and configured to constrain the soft actuator body inside the sleeve when actuated and to cause the soft actuator body to bend where it is not covered by the sleeve. 
         [0005]    In a method for mechanical actuation, fluid (e.g., air or liquid) is pumped into a chamber defined by the soft actuator body, causing the soft actuator body to bend where the soft actuator body is not covered by the sleeve, while the sleeve constrains bending of the soft actuator body where the sleeve covers the soft actuator body. 
         [0006]    Embodiments of these actuators can provide for safe human-robot interaction, where soft tissues (e.g., skin) can interact with soft and compliant robotic actuators to increase comfort and to reduce the risk of injury to the user. These soft actuators are suitable for a variety of uses including use as robotic actuators to assist human movement, use as a conformable gripper for manipulating objects and use in toys (e.g., as an interface for video games). 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a photographic image of a curling soft actuator body  14  without a sleeve. 
           [0008]      FIG. 2  is a photographic image of the curling soft actuator body  14  of  FIG. 1  after a change in pressure in the actuator body  14 . 
           [0009]      FIG. 3  is a photographic image of the soft actuator body  14  of  FIG. 1  surrounded by sleeves  16  respectively at its base and at its remote end. 
           [0010]      FIG. 4  is a photographic image of the actuator  12  of  FIG. 3  after a change in pressure in the actuator body  14 . 
           [0011]      FIG. 5  is an illustration of a soft actuator body  14  with a strain-limiting layer  54  on its right side; an initial position of the actuator body  14  is shown at left, while the curl in the actuator body  14  due to the strain-limiting layer  54  after a change in pressure in the actuator body  14  is shown at right. 
           [0012]      FIG. 6  is an illustration of a soft actuator body  14  surrounded by a sleeve  16  at its base and with a strain-limiting layer  54  on its right side; an initial position of the actuator body  14  is shown at left, while the curl in the actuator body  14  due to the strain-limiting layer  54  above the sleeve  16  after a change in pressure in the actuator body  14  is shown at right. 
           [0013]      FIG. 7  is an illustration of a soft actuator body  14  surrounded by sleeves  16  respectively at its base and at its remote end and with a strain-limiting layer  54  on its right side; an initial position of the actuator body  14  is shown at left, while the bend in the actuator body  14  due to the strain-limiting layer  54  between the sleeves  16  after a change in pressure in the actuator body  14  is shown at right. 
           [0014]      FIG. 8  shows a sleeve  16  thermoformed to a soft actuator body  14  via the application of heat. 
           [0015]      FIG. 9  shows the soft actuator body  14  with the sleeve  16  thermoformed thereon. 
           [0016]      FIG. 10  shows a sleeve  16  attached to a soft actuator body  14  via pinch clamps  24 ′ secured about the sleeve  16 . 
           [0017]      FIG. 11  shows a sleeve  16  attached to a soft actuator body  14  via zip ties  24 ″ secured about the sleeve  16 . 
           [0018]      FIG. 12  shows a sleeve  16  secured to a soft actuator body  14  via respective surfaces of hooks and loops  24 ′″ on the top side of one end of the sleeve  16  and on the bottom side of the opposite end of the sleeve  16 . 
           [0019]      FIG. 13  shows a sleeve  16  secured to a soft actuator body  14  via a lace  24 ″″ threaded through apertures along each of the opposite ends of the sleeve  16 . 
           [0020]      FIG. 14  shows a sleeve  16  secured to a soft actuator body  14  via glue  24 ′″″ inserted between the sleeve  16  and the soft actuator body  14 . 
           [0021]      FIG. 15  shows an actuator  12  with a plurality of joints formed between more than two sleeves  16  spaced along the length of the actuator  12 . 
           [0022]      FIG. 16  shows the actuator  12  of  FIG. 15  after a pressure change in the soft actuator body  14 , where the soft actuator body  14  bends between the sleeves  16 . 
           [0023]      FIG. 17  shows a variety of embodiments of actuators wherein the soft actuator body  14  is covered by one, two or three sleeve sections  16  and with the sleeves  16  extending different distances across the soft actuator body  14 . 
           [0024]      FIG. 18  shows a sleeve  16  that can act as a mounting substrate for electronics (e.g., a contact sensor  26  and a circuit board  28 ). 
           [0025]      FIGS. 19 and 20  show a sleeve  16  that can act as an anchor point for a soft sensor, such as a strain gauge  30  (e.g., connecting via hooks and loops, sewn, glued, etc.). 
           [0026]      FIGS. 21-24  show a sleeve  16  that can act as an interface to connect rigid devices to a soft connector (e.g., a scoop, lever, spring or any mechanism to be actuated); in this embodiment, the sleeve  16  includes threaded posts  32  to serve as the interface. 
           [0027]      FIGS. 25-27  show the integration or embedding of magnets  38  (e.g., to facilitate alignment during grasping, for attaching tools, or for use in rapid collection of ferrous metal objects). 
           [0028]      FIGS. 28 and 29  show the use of a sleeve  16  as a coupler to connect actuator bodies  14  in series. 
           [0029]      FIGS. 30 and 31  show the use of sleeves  16  connected in parallel to couple soft actuator bodies  14  together in parallel. 
           [0030]      FIG. 32  shows the use of a sleeve  16  to join four soft actuator bodies  14  into an “X-joint”. 
           [0031]      FIG. 33  shows the use of a sleeve  16  to join three soft actuator bodies  14  into an “T-joint”. 
           [0032]      FIG. 34  shows the use of a sleeve  16  to join two soft actuator bodies  14  end-to-end. 
           [0033]      FIG. 35  shows brushes  44  extending from a surface of a sleeve  16 . 
           [0034]      FIG. 36  shows bumps  46  protruding on a surface of a sleeve  16 . 
           [0035]      FIG. 37  shows loops  48  (alternatively, or in addition, hooks can be provided) on a surface of a sleeve  16 . 
           [0036]      FIG. 38  shows a sleeve  16  with perimeter channels  50  for routing tubes and wires to minimize snagging and tangling. 
           [0037]      FIG. 39  shows the sleeve  16  of  FIG. 38  with tubes and wires  52  fed through the perimeter channels  50  and with the sleeve  16  mounted on a soft actuator body  14 . 
           [0038]      FIGS. 40 and 41  show sleeve rings  16  that are narrow in width and spaced along a connecting rigid strip to provide multiple bending positions for the underlying soft actuator body  14 . 
           [0039]      FIGS. 42-44  show the bending of a soft actuator body  14  at sleeve spacings of 0, 15, and 30 mm, respectively; the shadow images show the actuators bending at different pressures. 
           [0040]      FIG. 45  shows a sleeve  16  with an aperture  22  to allow for bending of an underlying soft actuator body at the aperture  22 . 
           [0041]      FIGS. 46-48  show a sleeve  16  with a plurality of apertures  22  positioned at different length-wise and azimuthal locations on the sleeve  16  to provide for bending at different locations and about axes along differing orientations. 
           [0042]      FIG. 49  shows a sleeve  16  with embedded electrical circuits and wiring  62 . 
           [0043]      FIG. 50  shows a sleeve  16  that can connect a soft actuator  12  to a body part  63  (here, a finger). 
           [0044]      FIG. 51  shows an attempt to grasp a square object  66  with a manipulator including curling soft actuators  12  without sleeves. 
           [0045]      FIG. 52  shows a manipulator with curling soft actuators  12  covered with sleeves  16  having a length matching that of a side of an object  66  to be grasped. 
           [0046]      FIG. 53  shows the sleeved soft actuators  12  of the manipulator of  FIG. 52  grasping an object  66 . 
           [0047]      FIG. 54  shows soft actuator bodies  14  without sleeves supporting an object  66  under load. 
           [0048]      FIG. 55  shows soft actuators with sleeves  16  supporting an object  66  under a greater load. 
           [0049]      FIG. 56  shows soft actuators with sleeves  16  that have a fiber-reinforced laminate structure supporting an object  66  with a still greater load. 
           [0050]      FIGS. 57 and 58  show additional embodiments of soft actuator bodies  14  grasping an object  66 , respectively, with and without sleeves  16 . 
           [0051]      FIGS. 59 and 60  show a shape-matched manipulator with a sleeve  16  on a curling soft actuator body  14  and a second curling actuator without a sleeve. 
           [0052]      FIGS. 61-64  show a sleeve  16  that can be unrolled to provide an adjustable length of bending constraint on an underlying soft actuator body  14 . 
           [0053]      FIGS. 65-67  show a sleeve  16  that includes a segment that can be extended to provide an adjustable length of bending constraint on an underlying soft actuator body  14 . 
           [0054]      FIGS. 68 and 69  show a soft actuator body  14  with the adjustable-length sleeves  16  of  FIGS. 61 and 64  at both ends of the soft actuator body  14 , showing that the bend radius of the soft actuator body  14  decreases as the sleeves  16  are lengthened by further unrolling. 
           [0055]    Illustrations (a)-(d) of  FIG. 70  show a cross-sectional comparison of a fiber-reinforced actuator body  14 , with (c and d) and without (a and b) an inelastic (strain-limiting) fiber-reinforced laminate structure  54 , where (a) shows an illustrated cross section and actual side view of an unpressurized fiber-reinforced actuator body  14 ; (b) shows expansion of the walls of the actuator body  14  due to fluid pressurization; (c) demonstrates placement of an inelastic fiber-reinforced laminate  54  on a fiber-reinforced actuator body  14 ; and (d) shows an illustrated cross-section view of the actuator when a sleeve  16  is added. 
           [0056]    Illustrations (a)-(c) of  FIG. 71  show the range of motion of soft bending actuators with inelastic fiber-reinforced laminates on their flat surface with respective sleeve  16  spacings of (a) 0 mm, (b) 15 mm, and (c) 30 mm. 
           [0057]      FIG. 72  shows an unactuated linearly extending soft actuator  12  with an inner and outer sleeve  16 ′ and  16 ″ with apertures  22  through both sleeves  16  that serve as bending joints and a gap in the outer sleeve  16 ″ that serves as an extension segment  70  where the inner sleeve  16 ′ can longitudinally extend. The sleeves enable multi-segment motion 
           [0058]      FIG. 73  shows the soft actuator  12  of  FIG. 72  in an actuated state. 
           [0059]      FIG. 74  is a photographic image of a linearly extending soft actuator body  14  contained in a sleeve  16  with an aperture in the form of a slit to generate bending of the actuator. 
           [0060]      FIG. 75  is a photographic image of the linearly extending soft actuator of  FIG. 74  when actuated by fluid pumped into the soft actuator body  14 . 
           [0061]      FIG. 76  is a photographic image of a linearly extending soft actuator body  14  contained in a sleeve  16  with two apertures to generate bending of the actuator at each aperture in opposite directions due to the orientation of the apertures. 
           [0062]      FIG. 77  is a photographic image of a linearly extending soft actuator contained in a sleeve  16  with a plurality of apertures and uncut portions  69  of the sleeve  16  configured to generate bending of the actuator about a plurality of axes with different orientations. 
           [0063]      FIG. 78  is a photographic image of a linearly extending soft actuator converted into a bending actuator by a sleeve  16  with uncut portions  69  and a plurality of apertures that share a common orientation and consistent spacing there between. 
           [0064]      FIGS. 79 and 80  are photographic images of a power grip glove including a curling soft actuator for each finger, wherein each actuator includes a linearly extending soft actuator contained in a sleeve  16  having a plurality of apertures to convert the linear actuation of the soft actuator to a bending/curling motion. 
           [0065]      FIG. 81  shows a soft actuator body  14  dispensed from a reel and severable to produce the desired length. 
           [0066]      FIG. 82  shows a cut segment of the soft actuator body  14  of  FIG. 81  with caps  68  inserted at each end and with a pneumatic or hydraulic connection  60  in one of the end caps to enable the introduction of fluid into the soft actuator body  14 . 
           [0067]      FIGS. 83-85  provide perspective views of a soft actuator body  14  with a sleeve  16  at its distal end that includes gripping features  49 . 
           [0068]      FIGS. 86-88  illustrate embodiments of an actuator  12  with segments that can stiffen, which can therefore control deformation, via activation of vacuum jamming pouches  80  mounted on the sleeve  16 . 
           [0069]      FIG. 89  illustrates an actuator  12  that includes a vacuum jamming gripper  82  mounted on the sleeve  16 . 
       
    
    
       [0070]    In the accompanying drawings, like reference characters refer to the same or similar parts throughout the different views; and apostrophes are used to differentiate multiple instances of the same or similar items sharing the same reference numeral. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating particular principles, discussed below. 
       DETAILED DESCRIPTION 
       [0071]    The foregoing and other features and advantages of various aspects of the invention(s) will be apparent from the following, more-particular description of various concepts and specific embodiments within the broader bounds of the invention(s). Various aspects of the subject matter introduced above and discussed in greater detail below may be implemented in any of numerous ways, as the subject matter is not limited to any particular manner of implementation. Examples of specific implementations and applications are provided primarily for illustrative purposes. 
         [0072]    Unless otherwise defined, used or characterized herein, terms that are used herein (including technical and scientific terms) are to be interpreted as having a meaning that is consistent with their accepted meaning in the context of the relevant art and are not to be interpreted in an idealized or overly formal sense unless expressly so defined herein. For example, if a particular composition is referenced, the composition may be substantially, though not perfectly pure, as practical and imperfect realities may apply; e.g., the potential presence of at least trace impurities (e.g., at less than 1 or 2%) can be understood as being within the scope of the description; likewise, if a particular shape is referenced, the shape is intended to include imperfect variations from ideal shapes, e.g., due to manufacturing tolerances. Percentages or concentrations expressed herein can represent either by weight or by volume. 
         [0073]    Although the terms, first, second, third, etc., may be used herein to describe various elements, these elements are not to be limited by these terms. These terms are simply used to distinguish one element from another. Thus, a first element, discussed below, could be termed a second element without departing from the teachings of the exemplary embodiments. 
         [0074]    Spatially relative terms, such as “above,” “below,” “left,” “right,” “in front,” “behind,” and the like, may be used herein for ease of description to describe the relationship of one element to another element, as illustrated in the figures. It will be understood that the spatially relative terms, as well as the illustrated configurations, are intended to encompass different orientations of the apparatus in use or operation in addition to the orientations described herein and depicted in the figures. For example, if the apparatus in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the exemplary term, “above,” may encompass both an orientation of above and below. The apparatus may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
         [0075]    Further still, in this disclosure, when an element is referred to as being “on,” “connected to,” “coupled to,” “in contact with,” etc., another element, it may be directly on, connected to, coupled to, or in contact with the other element or intervening elements may be present unless otherwise specified. 
         [0076]    The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting of exemplary embodiments. As used herein, singular forms, such as “a” and “an,” are intended to include the plural forms as well, unless the context indicates otherwise. Additionally, the terms, “includes,” “including,” “comprises” and “comprising,” specify the presence of the stated elements or steps but do not preclude the presence or addition of one or more other elements or steps. 
         [0077]    The methods and actuator designs disclosed, herein, can put the power of soft actuator customization into the user&#39;s hands and can eliminate the need to mold a new soft actuator to fit a particular application. As described herein, sleeves  16  can be used to mechanically program soft actuators  12 , which allows rapid modification (e.g., on the order of minutes) of a soft actuator&#39;s motion and capabilities. As an example,  FIGS. 1 and 2  show the motion of a curling soft actuator  12  when actuated by an activation mechanism  18  (e.g., as a pump fills the soft actuator body  14  with fluid). One means for generating the curling motion is to adhere a strain-limiting layer  54  that resists elastic or plastic deformation along its length (relative to unrestrained portions of the soft actuator body  14 ), thereby causing curling of the actuator  12 , as shown in  FIG. 5 , when under stress (e.g., an increase in internal pressure). This motion can be adjusted by applying sleeves  16 , such as shrink tubing, to the soft actuator body  14  and leaving a full or partial opening where bending motion is desired, as shown in  FIGS. 3 and 4 . Wrapping the soft actuator body  14  with such a sleeve  16  can convert the soft curling actuator body  14  to a more-acutely bending actuator (or can convert a linear actuator into a bending actuator, as discussed below and as shown in  FIGS. 72-80 ) and can produce a distinctly different motion (e.g., joint-like bending). The use of sleeves  16  also enables new opportunities to add a variety of features and capabilities to the soft actuator body  14 , such as interfacing with sensors  26 , electronics, mechanical tools, and other soft actuators and inclusion of printed circuit boards  28  mounted thereon (see,  FIGS. 18-24, 35-39 and 49 ). As shown in  FIGS. 21 and 22 , the sleeve can also include mounts  32  (in the form of threaded posts in this embodiment) for mounting other objects  33  to the sleeve  16  or for mounting the sleeve  16  to other structures. As shown in  FIGS. 23 and 24 , the actuator  12  can be mounted to rigid links  34 , which are joined at a pivot  36  to form an actuating pivoting structure. 
         [0078]    Soft actuator bodies  14  of this disclosure include walls that define a chamber  20  that can be formed of, e.g., hyper-elastic silicone, thermo plastic elastomer, thermo plastic urethane, rubber, elastic polyurethane, or polyethylene. Accordingly, the soft actuator body  14  can be designed to expand its dimensions, e.g., to 200% of its original dimensions before failure, while the sleeve  16  in which the soft actuator body  14  is contained can be formed of a flexible, rigid, and/or elastomeric material (e.g., in the form of a non-expanding fabric with, for example, no more than 1/10th the elasticity of the soft actuator body  14 ), such that the sleeve  16  constrains the soft actuator body  14  and such that the soft actuator body  14  presses against the sleeve  16  when the soft actuator body  14  is expanded (e.g., by an increase in internal pressure). 
         [0079]    The combination of the soft actuator body  14  and constraining sleeve  16  can include any or all of the following features. First, the sleeves  16  can alter the motion of a soft actuator body  14 . A single sleeve  16  can be used to move the bending position anywhere along the length of the soft actuator body  14  by limiting any part of the soft actuator body  14  that is enclosed in the sleeve  16  from deforming, as shown in  FIG. 6 , and by promoting deformation at an aperture  22  (in the form, e.g. of a slit or a cut-out, as shown in  FIG. 45 ) in the sleeve  16 . In additional embodiments, two sleeves  16  can be positioned and spaced apart to move the bending position and to alter the actuator&#39;s radius of curvature to create joint-like bending, as shown in  FIGS. 3, 4, and 7 . Additionally, the sleeves  16  can be thermoformed; or secured with a securing mechanism  24 , such as pinch clamps  24 ′, laces  24 ″ (e.g., with cable ties), rubber bands  24 ′″, zip ties  24 ″″, inter-locking hook-and-loop structures  24 ″″′ (e.g., VELCRO adhesive), or sewn thread; or rolled on thermally welded on or glued to the soft actuator body  14 , as shown in  FIGS. 8-14 . In particular embodiments where the soft actuator  12  is used for medical applications, both the soft actuator body  14  and the sleeve  16  can be formed of or coated with a biocompatible material, such as silicone or parylene polymer. .In additional embodiments, sleeves  16  can be cut to different lengths to change the location and bending radius of “joints” created in the soft actuator  12 . Additionally, the sleeves  16  can be designed to be removable from the soft actuator body  14  to free the soft actuator body  14  for re-use [e.g., the sleeves  16  can be cut off, slid off, untied, pulled apart (particularly when hook and loop structures are used), removed via the application of heat, etc.] 
         [0080]    In still more embodiments, sleeves  16  can be used to create multiple joints with different radii of curvature around multiple axes on a single soft actuator body  14 , as shown in  FIGS. 15-17 and 46-48 . The soft actuator body  14  does not necessarily have to contain a strain-limiting layer. Alternatively, the soft actuator body can be a linear extending soft actuator or any elastomeric bladder; and the uncut band of sleeve material behind the aperture  22  can perform the function of the strain-limiting layer  54 , as shown in  FIGS. 73-80 . 
         [0081]    The sleeves  16  can also act as a medium to interface with a whole suite of applications including the following: acting as an anchor point for electronics (e.g., an inertial measurement unit and mechanical contact switches); acting as an anchor point for soft sensors  26  and  30  (e.g., may be secured via interlocking hook and loop structures, sewn together, glued together, etc.); acting as an interface to connect rigid devices to a soft actuator body  14  (e.g., coupling to the actuator  12 , via a mount  32 , a scoop, lever, spring, or any mechanism that needs to be actuated); integrating or embedding magnets  38  (e.g., to facilitate alignment during grasping, attaching tools  39 , or to use for rapid collection of ferrous metal objects  40 ), as shown in  FIGS. 25-27 ; connecting multiple soft actuator bodies  14  in parallel, as shown in  FIGS. 30 and 31 , or in series (e.g., serving as X-, T-, and L-joints or end-to-end joints, as shown in  FIGS. 28, 29, and 32-34 ), wherein the sleeves  16  can be used to create 3D structures; providing any of a variety of textures for gripping, twisting, sliding, or rolling objects (e.g., via brushes  44 , a sticky surface, a bumpy surface  46 , or via attachment mechanisms, such as hooks and/or loops  48 , as shown in  FIGS. 35-37 ); and routing tubing or wiring  52  through perimeter channels  50  to minimize snagging and tangling of the tubes and wires  52 , as shown in  FIGS. 38 and 39 . 
         [0082]    In  FIGS. 83-85 , a sleeve  16  that includes gripping features  49  for interfacing with objects is shown; the sleeve  16  can also extend further across the soft actuator body  14  and include apertures  22  or other features for bending or other forms of actuation, as shown in other embodiments. 
         [0083]    In other embodiments, as shown in  FIGS. 40 and 41 , connected ring-shaped sleeve  16  sections that are narrow in width and spaced appropriately along a strain-limiting layer  54  can still achieve many of the interface applications, described above, without significantly changing the curling motion of the actuator  12 . 
         [0084]    The sleeves  16  can be formed of a single piece of material with cut-outs or slits  22  at different longitudinal and radial positions along and about the sleeve  16 , as shown in  FIGS. 46-48, 76 and 77 , defining multiple bending positions along multiple axes and that can be used to join a plurality of soft actuator bodies  14 , as shown in  FIGS. 32-34  (e.g., with multiple interconnected sleeve ends). 
         [0085]    Shown in  FIGS. 42-44 , at one end of the sleeve  16  is a fixture  58  attached to the soft actuator body  14  and including the pneumatic connection  60  which provides for fluid communication between a pump  18  and the chamber  20  defined by the walls of the soft actuator body  14 . The range of motions of a 28A durometer sleeved soft bending actuator  12  at sleeve spacings of (a) 0 mm, (b) 15 mm, and (c) 30 mm are respectively shown for comparison in  FIGS. 42-44 . The shadow images  56  show the actuators  12  bending at different pressures. 
         [0086]    The sleeves  16  can be anchored to the surface of the soft actuator body  14  through mechanical features on the surface of the soft actuator body  14  (e.g., bumps, bellows, Kevlar ribs, other geometric locking features, etc.); and the sleeves  16  can be formed with fiber reinforcement. The sleeves  16  can also have integrated electrical wiring  62  (as shown in  FIG. 49 ), a circuit board  28 , heating elements, cooling elements, temperature sensors, routing channels  50 , capacitive sensors, force sensors  26 , strain sensors  30  and so forth. 
         [0087]    In particular applications, the sleeves  16  can connect a soft actuator body  14  to a human (or other animal) body part  63 , such as a finger, as shown in  FIG. 50  (wherein the actuator  12  may be, e.g., 3-15 cm in length with a thickness of, e.g., 0.5 to 2 cm), or to any other jointed body part. In other embodiments, the sleeves  16  can connect soft actuator bodies  14  to clothing. 
         [0088]    In additional embodiments, as shown in  FIGS. 52, 53, 55, 55, and 58-60 , soft actuators  12  can be assembled into a manipulator body  64 , where sleeves  16  can be cut to different lengths to match (e.g., within 5%) the shape/dimensions of an object  66  to be grasped. For comparison, manipulators with sleeve-less curling soft actuator bodies  14  are shown in  FIGS. 51, 54, and 57 , where the curled soft actuators  12  can be seen to not conform closely to the surfaces of the object  66  to be manipulated. In the embodiments of  FIGS. 54-56 , an additional downward force is applied to the object  66  via a hook  67  extending from the object  66 . Use of the proposed sleeve  16  enables improved shape matching to angular objects  66  and improved holding strength. In these embodiments, sleeve length can be tuned/adjusted (e.g., by rolling, sliding, screwing/unscrewing, etc.), as shown in  FIGS. 61-69 , to match the lengths of sides of the object  66  to be manipulated; and the sleeves  16  can be constructed from or combined with materials with rigid, flexible, and elastomeric properties. For example, a sleeve  16  can join two rigid components  54  to make a compliant joint, as shown in  FIGS. 70 and 71 . 
         [0089]      FIG. 70  provides a cross-sectional comparison of a fiber-reinforced actuator  12  with and without a fiber-reinforced laminate, where (a) shows an illustrated cross section and actual side view of an unpressurized fiber-reinforced actuator  12 ; (b) shows expansion of the actuator walls due to fluid pressurization (note the outward bowing of the flat face  15 ); (c) demonstrates placement of the fiber-reinforced laminate on a fiber-reinforced actuator  12 ; and (d) shows an illustrated cross-sectional view of the actuator  12  when a sleeve  16  is added. The combination of the sleeve  16  and fiber-reinforced laminate stiffens the flat face  15  and eliminates or reduces visual indications of bowing. 
         [0090]      FIG. 86  presents an alternative to the design of embodiment (c) in  FIG. 70 , where instead of integrating rigid elements  54  with the sleeve  16  to stiffen portions of the actuator, vacuum jamming pouches  80  are integrated into the sleeve  16 . In this embodiment, the fluid line  60  connects to a vacuum source. Contained in the vacuum jamming pouches  80  are loose particles or laminate layers initially at atmospheric pressure. However, when these sections are exposed to a vacuum, the pouch walls close in on the contents, restricting their movement, and causing a phase transition (i.e., jamming) of pouches  80  to a more rigid state. Advantageous features of this configuration include the ability to adjust the stiffness of a pouch  80  by adjusting the vacuum pressure, and reversibility, where the initial flexible state of the pouch  80  can be returned by releasing the vacuum. 
         [0091]      FIG. 87  presents a configuration of a sleeve  16 , where vacuum jamming pouches  80  are placed opposite apertures  22  to actively control deformation of the actuator  12  at the apertures  22 .  FIG. 88  presents an illustration of this concept where the soft actuator body  14  is pressurized; however, a portion of the soft actuator body  14  at one aperture  22  (the furthest right) is restricted because the vacuum jamming pouch  80 ′ is under a vacuum making it stiffer than the other pouch  80 , which is at atmospheric pressure. 
         [0092]    Vacuum jamming has also proven to provide effective means for gripping an object, as has been demonstrated by Cornell University and Empire Robotics, Inc. (see, e.g. US published patent application No. 20130106127 A1). To pick up an object, a vacuum jamming gripper  82 , as shown in  FIG. 89 , with an internal pressure at atmosphere, is placed on top of the object and conforms to it. Vacuum is applied to harden the gripper  82 , which generates gripping forces through friction from pinching, entrapment, and vacuum suction. Furthermore, the object can be released by injecting air into the gripper  82  to release the vacuum.  FIG. 89  presents a concept where a vacuum jamming gripper  82  can be integrated with a sleeve  16  such that, depending on the task at hand, this gripping capability can be arbitrarily added to or removed from an actuator  12 . 
         [0093]      FIG. 71  illustrates the range of motion of a 28A durometer soft bending actuator  12  with 0.8-mm-thick fiber-reinforced laminates on the flat surface  15  of the soft actuator body  14  and with (a) 0 mm, (b) 15 mm, and (c) 30 mm spacing across the apertures  22  in the sleeves  16 . A soft actuator  12  with an extension segment  70  that permits localized extension is shown in  FIGS. 72 and 73 . In this embodiment, the extension is facilitated by a gap between sections of a substantially inelastic outer sleeve  16 ″ and an expandable inner sleeve  16 ′ over a soft actuator body  14 . Where the outer sleeve  16 ″ is removed (producing a gap), the exposed inner sleeve  16 ′ can radially expand and contract with fluid flow into and out of the soft actuator  12 . At the bending joints, apertures  22  can be made in both sleeves  16 ′ and  16 ″ without completely severing the sleeves  16 ′ and  16 ″ to facilitate bending of the soft actuator  12  at these locations. Furthermore, for actuators  12  that produce more than one type of motion (such as bending, extending, contracting, extending-twisting, and bending-twisting to name a few), the sleeve  16  can be used as a means to lock or unlock these motions. 
         [0094]    As shown in  FIGS. 74-76 , the sleeve  16  includes an uncut portion  69  behind the aperture  22  to provide a continuous length of sleeve material at each of the bending/pivot locations. A linearly extending soft actuator body  14  contained in a sleeve  16  with a plurality of apertures (slits)  22  configured to generate bending of the actuator about a plurality of axes with different orientations is shown in  FIG. 77 ; and a linearly extending soft actuator body  14  converted into a bending actuator by a sleeve  16  with a plurality of apertures  22  that share a common orientation and consistent spacing there between is shown in  FIG. 78 . 
         [0095]    A power grip glove  72  including a curling soft actuator  12  for each finger is shown in  FIGS. 79 and 80 , wherein each actuator  12  includes a linearly extending soft actuator body  14  contained in a sleeve  16  having a plurality of apertures  22  to convert the linear actuation of the soft actuator body  14  to a bending/curling motion. The position of the apertures  22  can be customized to align with the location of the wearer&#39;s joints. The elasticity of the soft actuator body  14  allows the actuator  12  to extend at joints to, e.g., maintain contact (without slipping) with a bending finger with which the actuator  12  is in contact. In other embodiments, the actuators  12  can be incorporated into another type of wearable apparel, wherein the actuators  12  can be configured along other joints and designed to generate greater or lesser force, as needed. Control electronics can also be incorporated into the apparel for controlling the pump  18  and thereby controlling actuation of the actuators  12 . 
         [0096]    In some applications, the actuator  12  can be disposable (e.g., discarded after a specified period of use, such as after one month of use) and replaced, while retaining the pump  18  for long-term reuse. 
         [0097]    In other embodiments, the soft actuators  12  can be used independently (e.g., to create robotic hand) without joining the soft actuators  12  to a body part of a human or other organism. For example, a plurality of actuators  12  can extend from a hub to form a grasper that can pick up and manipulate objects in an environment that may be inhospitable to humans (e.g., at great depths, such as 200 meters deep or more, undersea). 
         [0098]    In particular embodiments, the soft actuator body  14  can be provided on a reel, as shown in  FIG. 81 , and cut to a desired length. Using this embodiment, soft actuators  12  can be rapidly assembled by cutting the desired length of soft actuator body  14  from a reel and then capping the ends of the resulting soft actuator bodies  14 , as shown in  FIG. 82 . At least one of the end caps  68  illustrated in  FIG. 82  includes an embedded pneumatic or hydraulic connection passing there through (and to which a pneumatic or hydraulic pump  18  coupled with a fluid source is connected) to allow fluid to be pumped into the soft actuator body  14  to power its actuation; and a sleeve  16  can be fitted over the soft actuator body  14  with apertures  22  to allow for bending or curving of the actuator,  12  as desired. 
         [0099]    In additional embodiments, the sleeve  16  can be formed of a material that is anisotropic to provide the actuator  12  with different properties (e.g., different strain characteristics) along different axes. Additionally, the sleeve  16  can be formed of a woven material that can then be made rigid by coating it with an epoxy or polyurethane. Further still, sleeves  16  can be applied to monolithic soft actuator bodies  14  that contain a plurality of air chambers. In still more embodiments, the sleeve  16  can include an electronic sensor [e.g., electromyography (EMG)] configured to detect signals (e.g., electrical signals, muscle activity) that accompany a human&#39;s effort to activate muscles to generate movement, which can then be mechanically assisted by the soft actuator  12  of this disclosure. 
         [0100]    In describing embodiments of the invention, specific terminology is used for the sake of clarity. For the purpose of description, specific terms are intended to at least include technical and functional equivalents that operate in a similar manner to accomplish a similar result. Additionally, in some instances where a particular embodiment of the invention includes a plurality of system elements or method steps, those elements or steps may be replaced with a single element or step; likewise, a single element or step may be replaced with a plurality of elements or steps that serve the same purpose. Further, where parameters for various properties or other values are specified herein for embodiments of the invention, those parameters or values can be adjusted up or down by 1/100 th , 1/50 th , 1/20 th , 1/10 th , 1/5 th , 1/3 rd , 1/2, 2/3 rd , 3/4 th , 4/5 th , 9/10 th , 19/20 th , 49/50 th , 99/100 th , etc. (or up by a factor of 1, 2, 3, 4, 5, 6, 8, 10, 20, 50, 100, etc.), or by rounded-off approximations thereof, unless otherwise specified. Moreover, while this invention has been shown and described with references to particular embodiments thereof, those skilled in the art will understand that various substitutions and alterations in form and details may be made therein without departing from the scope of the invention. Further still, other aspects, functions and advantages are also within the scope of the invention; and all embodiments of the invention need not necessarily achieve all of the advantages or possess all of the characteristics described above. Additionally, steps, elements and features discussed herein in connection with one embodiment can likewise be used in conjunction with other embodiments. The contents of references, including reference texts, journal articles, patents, patent applications, etc., cited throughout the text are hereby incorporated by reference in their entirety; and appropriate components, steps, and characterizations from these references may or may not be included in embodiments of this invention. Still further, the components and steps identified in the Background section are integral to this disclosure and can be used in conjunction with or substituted for components and steps described elsewhere in the disclosure within the scope of the invention. In method claims, where stages are recited in a particular order—with or without sequenced prefacing characters added for ease of reference—the stages are not to be interpreted as being temporally limited to the order in which they are recited unless otherwise specified or implied by the terms and phrasing.