Variable Friction Finger Assembly

Abstract

The present disclosure relates to a finger assembly for a manipulation device. The finger assembly comprises a rigid body having a surface configured to engage an object. The surface has a first coefficient of friction and comprises one or more apertures. The finger assembly further comprises an expandable element received within the rigid body having a coefficient of friction higher than the first coefficient of friction. When the expandable element is expanded, a region of the expandable element protrudes through the one or more apertures to form one or more protrusions.

Description

[Technical field]

[0001] The present invention relates generally to the field of finger assemblies for handling devices, and more particularly to finger assemblies that can have a variable coefficient of friction. [Background technology]

[0002] An automated picking system requires a robotic picking station that can select an item from a first container, such as a tote or other storage unit, grasp the item, and then move the item into a second container, such as a bag. When manipulating an item, it is beneficial for the finger assemblies of the manipulating device to have low friction when they are brought into contact so as to grasp the item. However, when an item is to be grasped, for example for lifting, it is beneficial for the finger assemblies to have high friction.

[0003] Spiers et al., "Variable-Friction End effector Surfaces to Enable Within-Hand Manipulation via Gripping and Sliding," pp. 4116-4123, IEEE Robotics and Automation Letters, vol. 3, no. 4, October 2018, discloses an end effector in which a low-friction surface can be moved against a high-friction surface. In operation, the low-friction surface slides over the surface of an object to be gripped, and then the high-friction surface is used to grip the object.

[0004] The present invention has been devised against this background. Summary of the Invention

[0005] Thus, the present invention provides a finger assembly for a manipulation device having a low friction surface in a passive state and a high friction surface in an active state. In general, the present invention introduces a finger assembly comprising a rigid body in which an expandable element is received. The rigid body has a low friction gripping surface and one or more apertures formed in the low friction gripping surface. In the active state, pressure on the finger element can be increased such that a region of the expandable element protrudes through the one or more apertures. The protrusions have high friction and allow an object to be gripped by the two opposing finger assemblies.

[0006] Accordingly, the present invention provides in a first aspect a finger assembly for a manipulation device, the finger assembly comprising: a rigid body, wherein the rigid body has a surface having a first coefficient of friction and configured to engage an object, the surface comprising one or more apertures; and an expandable element received within the rigid body, the expandable element having a coefficient of friction higher than the first coefficient of friction; and wherein, when the expandable element is expanded, a region of the expandable element protrudes through the one or more apertures to form one or more protrusions.

[0007] A mesh is formed on the surface of the expandable element. The mesh may be formed on the surface of the expandable element forming one or more protrusions. The application of the mesh may increase the stability of the protrusions when the expandable element is expanded and may increase the physical durability and resiliency of the expandable element.

[0008] The rigid body may comprise a back surface opposite the surface configured to engage the object and one or more stiffening elements connecting the back surface to the surface configured to engage the object. The stiffening elements increase the stiffness of the finger assembly and reduce the risk that expansion of the expandable element distorts the finger assembly, for example by bending the gripping surface.

[0009] At least one of the one or more apertures is substantially circular. Alternatively, at least one of the one or more apertures may be substantially elongated. Alternatively, in embodiments comprising multiple apertures, one of the multiple apertures may be substantially circular and another of the multiple apertures may be substantially elongated. That is, the finger assembly may comprise apertures of different shapes and / or sizes. The finger assembly may comprise an actuator that, in use, may be actuated to move the finger assembly. The actuator may move the finger assembly in multiple axes of movement and may be used to rotate the actuator in multiple axes of rotation.

[0010] According to a second aspect of the present invention there is provided a manipulation device comprising a first finger assembly according to the first aspect opposing a second finger assembly according to the first aspect, wherein a controller is configured to move the first finger assembly relative to the second finger assembly to engage an object and to inflate expandable elements of the first and second finger assemblies during engagement of the object by the first and second finger assemblies.

[0011] The controller may be configured to inflate the expandable element of the first finger assembly and the expandable element of the second finger assembly depending on the position of the first finger assembly and the second finger assembly relative to the object. The controller may be configured to inflate the expandable element of the first finger assembly and the expandable element of the second finger assembly when the first and second finger assemblies are moved into proximity with the object. The controller may be configured to inflate the expandable element of the first finger assembly and the expandable element of the second finger assembly when the first and second finger assemblies are moved into contact with the object.

[0012] A degree of expansion applied to the expandable element of the first finger assembly and the expandable element of the second finger assembly can be varied and the degree of expansion applied can be controlled to vary the height of the protrusion relative to a surface configured to engage an object.

[0013] According to a third aspect of the present invention, there is provided a method of manipulating an object, the method comprising the steps of: a) moving a first finger assembly according to the first aspect relative to a second finger assembly according to the first aspect to engage the object, b) expanding an expandable element of the first finger assembly and an expandable element of the second finger assembly, c) engaging the object with the first and second finger assemblies, and d) manipulating the object. The method may further comprise the steps of e) deflating the expandable element of the first finger assembly and the expandable element of the second finger assembly, and f) disengaging at least one of the first finger assembly or the second finger assembly from the object.

[0014] These and other aspects of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0015] [Figure 1] 1 is a schematic diagram of a control device according to an embodiment of the present invention. [Diagram 2] 2 is a schematic diagram of a finger assembly for use with the manipulation device of FIG. 1; [Diagram 3] 3 is a schematic diagram of a gripping surface of the finger assembly of FIG. 2; [Figure 4] 3 is a schematic diagram of an expandable element of the finger assembly of FIG. 2; [Diagram 5] 3 is a schematic diagram of a cross section of the finger assembly of FIG. 2 parallel to the gripping plane; [Figure 6] 3 is a schematic diagram of a cross section of the finger assembly of FIG. 2 perpendicular to the gripping plane. [Figure 7] 3 is a schematic diagram of a cross section of the finger assembly of FIG. 2 perpendicular to the gripping plane. [Figure 8] 3 is a schematic diagram of a cross section of the finger assembly of FIG. 2 perpendicular to the gripping plane. [Figure 9] FIG. 3 is a schematic side view of the finger assembly of FIG. 2; [Figure 10] FIG. 3 is a schematic side view of the finger assembly of FIG. 2; [Figure 11] 11 is a schematic cross-sectional view parallel to the gripping plane of an alternative embodiment of a finger assembly according to the present invention; [Figure 12] 12 is a schematic diagram of an expandable element of the finger assembly of FIG. 11 . [Figure 13] 12 is a schematic diagram of a gripping surface of the finger assembly of FIG. 11; [Figure 14] FIG. 12 is a schematic side view of the finger assembly of FIG. 11 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] In the drawings, like features are appropriately designated by like reference numerals.

[0017] In the following description, some specific details are included to provide a thorough understanding of the disclosed examples. However, one of ordinary skill in the art will recognize that other examples may be implemented without one or more of these specific details, or with other components, materials, etc., and structural changes may be made without departing from the scope of the present invention as defined in the appended claims. Furthermore, references to terms with implied orientation in the following description are not intended to be limiting, but merely to refer to the orientation of the features as shown in the accompanying drawings. In some examples, well-known features or systems, such as processors, sensors, storage devices, network interfaces, fasteners, electrical connectors, etc., have not been shown or described in detail to avoid unnecessarily obscuring the description of the disclosed embodiments.

[0018] Unless the context requires otherwise, throughout this specification and the appended claims, the word "comprise" and variations thereof, such as "comprises" and "comprising," are to be interpreted in their open, inclusive sense, such as "including, but not limited to."

[0019] Throughout this specification, references to "one," "an," or "another" applied to an "embodiment," "example," or "implementation" mean that a particular referenced feature, structure, or characteristic that is described in connection with an embodiment, example, or implementation is included in at least one embodiment, example, or implementation. Thus, the appearances of phrases such as "in one embodiment" in various places throughout this specification do not necessarily all refer to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments, examples, or implementations.

[0020] Please note that as used in this specification and the appended claims, the user forms "a," "an," and "the" include plural referents unless the content clearly dictates otherwise. Please also note that the term "or" is generally used in its sense to include "and / or" unless the content clearly dictates otherwise.

[0021] Fig. 1 shows a schematic diagram of a manipulation device 10 according to an embodiment of the invention, comprising a first finger assembly 12a facing a second finger assembly 12b, and a controller 14. Each of the first and second finger assemblies 12a, 12b includes an inflatable element (not shown in Fig. 1), the outer surface of which comprises a gripping surface arranged to grip an object 16 to be manipulated. The manipulation device 10 further comprises a first actuator 18a and a first pressure regulation means 20a, both associated with the first finger assembly 12a, and a second actuator 18b and a second pressure regulation means 20b, both associated with the second finger assembly 12b. The first and second pressure regulation means 20a, 20b are connected to their associated finger assemblies 12a, 12b by respective pressure lines 27a, 27b and other suitable connectors. The controller 14 comprises an electronic processor 21 having one or more electrical inputs for receiving an input signal, for example a visual data input signal 23 from an optical sensor 26 forming part of the manipulation device 10, and one or more electrical outputs for outputting one or more control signals 22a, 22b, 24a, 24b to the first and second actuators and the pressure regulating means 18a, 18b, 20a, 20b in response to the visual data input signal 23a, 23b. For example, the controller 14 is configured to output a first actuation control signal 22a for moving the first finger assembly 12a based on the visual data input signal 23. The first actuator 18a is configured to receive the first actuation control signal 22a and to move the first finger assembly 12a relative to the second finger assembly 12b in response to the first actuation control signal 22a. Similarly, the controller 14 can also output a second actuation control signal 22b for moving the second finger assembly 12b in response to the visual data input signal 23. The second actuator 18b is configured to receive a second actuation control signal 22b and to move the second finger assembly 12b relative to the first finger assembly 12a in response to the second actuation control signal 22b.These movements may include rotation of one of the first or second finger assemblies 12a, 12b relative to the other of the first or second finger assemblies 12a, 12b about multiple axes of movement. Such movements may allow an object 16 to be grasped between the first and second finger assemblies 12a, 12b. The first and second finger assemblies 12a, 12b may be movable together such that an object 16 grasped therebetween may be moved from a first position to a second position. The controller 14 is configured to output inflation control signals 24a, 24b in response to the visual data input signal 23 to control the first or second pressure regulating means 20a, 20b to vary the pressure inside the first or second finger element 12a, 12b to change the compliance of the respective inflatable element. Specifically, the controller 14 is arranged to output a first inflation control signal 24a based on the visual data input signal 23, and the first pressure regulating means 20a is configured to receive the first inflation control signal 24a and pressurize the first finger assembly 12a in response to the first inflation control signal 24a. Similarly, the controller 14 is arranged to output a second inflation control signal 24b based on the visual data input signal 23, and the second pressure regulating means 20b is configured to receive the second inflation control signal 24b and pressurize the second finger assembly 12b in response to the second inflation control signal 24b to vary the compliance of its inflatable element. To generate the control signals 22a, 22b, 24a, 24b, the controller 14 further comprises a memory device 28 electrically coupled to the electronic processor 21 and having instructions stored therein. The electronic processor 21 is configured to access the memory device 28 and execute the instructions stored therein to carry out the above-mentioned process.

[0022] 2-10 show schematic diagrams of a finger assembly 12' according to an embodiment of the invention suitable for use in the manipulation device 10. The finger assembly 12' comprises a rigid body 30 that receives an expandable element.

[0023] Referring to Figure 2, which illustrates a schematic perspective view of the finger assembly 12', the rigid body 30 is substantially cuboidal and includes a back surface 34 in which the actuator 18' is received. The rigid body 30 further includes a gripping surface 36 (not shown in Figure 2) opposite the back surface 34. The gripping surface 36 is configured to engage the object 16 to be manipulated and is connected to the back surface 34 by two side surfaces 38 and two end surfaces 40. Figure 3 shows a diagram of the gripping surface 36 including one or more apertures 42. In this embodiment, the gripping surface 36 includes a plurality of apertures 42.

[0024] 4 and 5 show schematic views of a cross section of the rigid body 30. FIG. 4 shows a cross section of the rigid body 30 in a plane parallel to and between the back and gripping surfaces 34, 36. From this view, it can be seen that the rigid body 30 comprises a number of reinforcing elements 44, which in this embodiment comprise a number of posts 44. The posts 44 extend between the back surface 34 and the gripping surface 36 and connect them to increase the rigidity of the rigid body 30. FIG. 4 shows the position of the number of apertures 42 formed in the gripping surface 36 relative to the position of the posts 44, the apertures 42 being shown in dotted lines. It can be seen that the posts 44 are arranged so as not to be located under one of the apertures 42. FIG. 5 shows a cross section of the finger assembly 12' in a plane perpendicular to the gripping surface 36 (and also to the back surface 34), showing the connection of the back surface 34 and the gripping surface 36 by the posts 44.

[0025] 6 shows a schematic diagram of the expandable element 32 comprising a plurality of apertures 46 arranged to align with a plurality of posts 44 formed in the rigid body 30 when the expandable element 32 is received within the rigid body 30. The material comprising the rigid body 30 has a first coefficient of friction and the material comprising the expandable element 32 has a second coefficient of friction, the second coefficient of friction being higher than the first coefficient of friction.

[0026] FIG. 7 illustrates a schematic of the cross-sectional view of FIG. 5 in which the expandable element 32 is received within the rigid body 30 such that each of the posts 44 is received within a respective one of the openings 46 formed in the expandable element 32. The size or diameter of the openings 46 is greater than the size of the posts 44 to allow the expandable element 32 to move relative to the posts 44. In other embodiments, the sizes of the openings and posts 46, 44 are substantially equal to minimize the relative movement therebetween and thus reduce wear and tear introduced. FIG. 7 illustrates the expandable element 32 when in an unexpanded or inactive state, and FIG. 8 illustrates an exterior side view of the finger assembly 12' when the expandable element 32 is in an unexpanded state. In an alternative embodiment, the expandable element 32 may include a plurality of extrusions that substantially occupy the entire volume of the rigid body 30 in an unexpanded state and are positioned to coincide with the positions of the plurality of openings 46. The extrusions are positioned such that their end faces are substantially flush with the gripping surface 36 of the rigid body 30 when the expandable element 32 is unexpanded. This arrangement allows the extrusions to engage the object 16 with little deformation of the expandable element 32, meaning that less compression of the expandable element 32 can be applied compared to current embodiments.

[0027] In use, the expandable element 32 is expanded by the pressure regulating means 20' in accordance with the expansion control signal 24', such that the expandable element 32 expands such that a portion of the expandable element 32 extends through the plurality of apertures 42 formed in the gripping surface 36. FIG. 9 shows a cross-sectional view of the finger assembly 12' when the expandable element 32 is in an expanded (or active) state within the rigid body 30. When the expandable element 32 is in this state, a plurality of protrusions 48 are formed, the diameter and position of which are limited by the size and position of the apertures 42 formed in the gripping surface 36. FIG. 10 shows an exterior side view of the finger assembly 12' when the expandable element 32 is in an expanded state, showing the plurality of protrusions 48 of the expandable element 32 on the gripping surface 36.

[0028] 11 to 14 show schematic diagrams of an alternative example of a finger assembly 12' suitable for use in the manipulation device 10. The finger assembly 12' is as described above with reference to FIGS. 2 to 10, except that the gripping surface 36 of the rigid body 30 comprises three elongated apertures 42 and the reinforcing element 44 comprises two elongated supports. As a result, the expandable element 32 comprises two elongated apertures 46 having a size and position within the expandable element 32 to allow the expandable element 32 to be received within the rigid body 30. As described above, when the expandable element 32 is in an unexpanded state, the expandable element 32 is fully received within the rigid body 30. When the expandable element 32 is expanded, a portion of the expandable element 32 may protrude through the elongated apertures 42 of the gripping surface 36 to form a plurality of protrusions 48. In this example, the protrusions 48 comprise three linear protrusions extending along a portion of the length of the gripping surface 36.

[0029] The rigid body 30 may be formed by additive manufacturing, injection molding, or other conventional machining techniques. As mentioned above, the reinforcing element 44 connects the underside and gripping surfaces 34, 36 to increase the rigidity of the rigid body 30 and reduce deformation of the gripping surface 36 when the expandable element 32 is expanded. The reinforcing element 44 also acts to limit the movement of the expandable element 32 upon expansion. The rigid body 30 may be formed in two halves that may be connected together to surround the expandable element 32. The expandable element 32 preferably comprises a single inlet that provides a fluid connection between the interior of the expandable element 32 and the corresponding pressure line 27' through which it may be expanded. The expandable element 32 may be formed from a flexible silicone material. The expandable element 32 may be formed from two layers or flexible silicone material that may be firmly connected together, for example by the use of an adhesive. The inlet may be formed from a hard silicone material that can receive a pressurized air supply. The pressure regulating means 20' may be configured to contract the expandable element 32 such that a partial vacuum exists within the expandable element 32 in an uninflated state to ensure that all of the expandable element 32 is stored within the rigid body 30. A mesh may be applied to the face of the expandable element 32 that forms the protrusions 48 when expanded. The mesh reinforces the expandable element 32 and makes it more elastic. Also, the patterning of the mesh may further increase the coefficient of friction of the protrusions 48 that form when the expandable element 32 is expanded. The mesh also reduces the amount by which the expandable element 32 can be expanded, allowing a higher pressure to be applied, thus allowing a greater gripping force, and less compliance. In an alternative embodiment, the mesh may be embedded in the expandable element 32.

[0030] When the finger assemblies 12a, 12b are manipulated to contact the object 16 to be grasped, the finger assemblies 12a, 12b preferably have low friction while they are positioned relative to the object 16. Thereafter, the finger assemblies 12a, 12b preferably have high friction so that the object 16 can be effectively grasped and manipulated, for example by picking up the object 16 and moving it from a first position to a second position. It can be seen that the finger assembly 12' addresses this issue since the frictional surface on the underside of the finger assembly 12' can be used to engage the object 16 when the expandable element 32 is in an unexpanded state. Once contact is made, the expandable element 32 is expanded and thus the expanded protrusions 48, which have a higher friction, can grasp the object 16 so that it can be manipulated. The higher friction of the expanded protrusions 48 allows a greater frictional force to be applied to the object 16. When the protrusions 48 are expanded, they have a degree of flexibility that may prevent the object 16 from being damaged by being grasped too tightly. Once the object 16 is manipulated, for example, the object 16 may be moved from a first position to a second position, and then the expandable element 32 may be uninflated and the finger assembly 12' may be disengaged from the object 16.

[0031] The manipulation device 10 may include a contact sensor (not shown in FIG. 1) instead of or in addition to the optical sensor 26. The contact sensor detects when the gripping surfaces 36 of the first and second finger assemblies 12a, 12b are in contact with the object 16 and outputs one or more signals that are received as input signals by the electronic processor 21 of the controller 14. The electronic processor 21 then outputs one or more inflation control signals 24' to the pressure regulating means 20' in response to the input signals to inflate the inflatable element 32 when both the first finger assembly 12a and the second finger assembly 12b are in contact with the object 16. Alternatively or additionally, the manipulation device 10 may include a proximity sensor (not shown in FIG. 1) that detects when the gripping surfaces 36 of the first and second finger assemblies 12' are within a specified distance from the object 16. The output signal of the proximity sensor is then received as an input signal by the electronic processor 21 of the controller 14, which outputs one or more inflation control signals 24' based on the input signal to the pressure regulating means 20' to inflate the expandable element 32 when the first and second finger assemblies 12a, 12b are sufficiently close to the object 16 to be grasped. The outputs from both the proximity sensor and the contact sensor may be used to determine the expansion of the expandable element 32.

[0032] Many modifications and variations may be made to the above-described embodiments without departing from the scope of the present invention. Multiple levels of expansion of the expandable element 32 may be provided so that the height of the projections 48 relative to the gripping surface 36 may be varied. This allows different levels of gripping force to be applied, the gripping force being determined by the degree of expansion applied to the expandable element 32. It should be understood that the number, size, and shape of the apertures 42 formed in the gripping surface 36 may be varied. For example, some embodiments of the finger assembly 12' may include a single aperture 42 in the gripping surface 36 that is relatively larger than that used in finger assemblies 12' that include multiple apertures 42. In some applications, it may be preferable for the projections 48 to be actuated in different areas of the gripping surface 36. In such cases, the finger assembly 12' may include multiple expandable elements 32, each of which may be independently expanded or unexpanded in a controllable manner.

[0033] In one aspect, the present invention relates to a finger assembly 12' for use with a manipulation device 10. In one state, the finger assembly 12' has a low coefficient of friction, and in a second state, the finger assembly 12' has a relatively high coefficient of friction. This is accomplished by disposing an expandable element 32 within a rigid body 30, which includes one or more apertures 42. Expanding the expandable element 32 causes a portion of the expandable element to protrude through one or more of the apertures 42, increasing the coefficient of friction of the finger assembly 12'.

[0034] The above description has been presented for purposes of illustration only and is not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. It will be understood that modifications and variations can be made to the described embodiments without departing from the scope of the invention as defined in the appended claims. The following is a summary of the claims as originally filed: [1] A finger assembly for a manipulation device, the finger assembly comprising: a rigid body; and an expandable element received within the rigid body; the rigid body has a first coefficient of friction and comprises a surface configured to engage an object, the surface comprising one or more apertures; the expandable element has a coefficient of friction greater than the first coefficient of friction; A finger assembly, wherein when the expandable element is expanded, regions of the expandable element protrude through the one or more apertures to form one or more protrusions. [2] The finger assembly described in [1], wherein a mesh is formed on a surface of the expandable element. [3] The finger assembly described in [2], wherein the mesh is formed on a surface of the expandable element forming the one or more protrusions. [4] A finger assembly described in any one of [1] to [3], wherein the rigid body has a back surface opposite the front surface configured to engage an object, and one or more reinforcing elements connecting the back surface to the front surface configured to engage an object. [5] A finger assembly described in any one of [1] to [4], wherein at least one of the one or more apertures is substantially circular. [6] A finger assembly described in any one of [1] to [4], wherein at least one of the one or more apertures is substantially elongated. [7] A manipulation device comprising a first finger assembly described in any one of [1] to [6] facing a second finger assembly described in any one of [1] to [6], and a controller, wherein the controller is configured to move the first finger assembly relative to the second finger assembly to engage an object, and to expand the expandable elements of the first and second finger assemblies during engagement of the object by the first and second finger assemblies. [8] The device described in [7], wherein the controller is configured to expand the expandable element of the first finger assembly and the expandable element of the second finger assembly depending on the positions of the first finger assembly and the second finger assembly relative to the object. [9] The device described in [8], wherein the controller is configured to expand the expandable element of the first finger assembly and the expandable element of the second finger assembly when the first and second finger assemblies are moved into proximity with the object.

[10] The device described in [8], wherein the controller is configured to expand the expandable element of the first finger assembly and the expandable element of the second finger assembly when the first and second finger assemblies are moved into contact with the object.

[11] The device described in any one of [7] to

[10] , wherein the degree of expansion applied to the expandable element of the first finger assembly and the expandable element of the second finger assembly is varied.

[12] The device of

[11] , wherein a height of the protrusions relative to the surface configured to engage an object varies depending on the degree of expansion applied.

[13] A method of manipulating an object, comprising: a) moving a first finger assembly according to any one of claims [1] to [6] relative to a second finger assembly according to any one of claims [1] to [6] to engage an object; b) expanding the expandable element of the first finger assembly and the expandable element of the second finger assembly; c) engaging the object with the first and second finger assemblies; d) manipulating the object; A method for providing the above.

[14] e) deflating the expandable element of the first finger assembly and the expandable element of the second finger assembly; and f) disengaging at least one of the first finger assembly or the second finger assembly from the object. The method of claim 13, further comprising:

Claims

1. A finger assembly for a manipulation device, the finger assembly comprising: a rigid body; and an expandable element received within the rigid body; the rigid body having a first coefficient of friction and comprising a surface configured to engage an object, the surface comprising one or more apertures; the expandable element has a coefficient of friction greater than the first coefficient of friction; when the expandable element is expanded, a region of the expandable element protrudes through the one or more apertures to form one or more protrusions; the rigid body comprising a back surface opposite the front surface configured to engage the object, and one or more stiffening elements connecting the back surface to the front surface configured to engage the object; The expandable element includes an opening that aligns with the stiffening element.

2. The finger assembly of claim 1 , wherein a mesh is formed on a surface of the expandable element.

3. The finger assembly of claim 2 , wherein the mesh is formed on a surface of the expandable element that forms the one or more protrusions.

4. The finger assembly of claim 1 , wherein at least one of the one or more apertures is substantially circular.

5. The finger assembly of claim 1 , wherein at least one of the one or more apertures is substantially elongated.

6. 6. A manipulation device comprising: a first finger assembly as described in any one of claims 1 to 5 facing a second finger assembly as described in any one of claims 1 to 5; and a controller, wherein the controller is configured to move the first finger assembly relative to the second finger assembly to engage an object, and to expand the expandable elements of the first and second finger assemblies during engagement of the object by the first and second finger assemblies.

7. 7. The apparatus of claim 6, wherein the controller is configured to expand the expandable element of the first finger assembly and the expandable element of the second finger assembly depending on positions of the first finger assembly and the second finger assembly relative to the object.

8. 8. The apparatus of claim 7, wherein the controller is configured to expand the expandable element of the first finger assembly and the expandable element of the second finger assembly when the first and second finger assemblies are moved into proximity with the object.

9. 8. The apparatus of claim 7, wherein the controller is configured to expand the expandable element of the first finger assembly and the expandable element of the second finger assembly when the first and second finger assemblies are moved into contact with the object.

10. 10. The apparatus of claim 6, wherein the degree of expansion applied to the expandable element of the first finger assembly and the expandable element of the second finger assembly is varied.

11. The device of claim 10 , wherein a height of the protrusions relative to the surface configured to engage an object varies depending on the degree of expansion applied.

12. 1. A method of manipulating an object, comprising: a) moving a first finger assembly according to any one of claims 1 to 5 relative to a second finger assembly according to any one of claims 1 to 5 to engage an object; b) expanding the expandable element of the first finger assembly and the expandable element of the second finger assembly; c) engaging the object with the first and second finger assemblies; d) manipulating the object; A method for providing the above.

13. e) deflating the expandable element of the first finger assembly and the expandable element of the second finger assembly; f) disengaging at least one of the first finger assembly or the second finger assembly from the object; The method of claim 12 further comprising:

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