阅读说明：本技术 包括电极结构的承载可变强化装置 (Load bearing variable reinforcement device comprising electrode structure ) 是由 M·P·罗威 S·S·潘瓦尔 于 2021-06-03 设计创作，主要内容包括：本公开涉及一种可变强化装置,包括第一电极结构和第二电极结构的。第一电极结构包括电极延伸部,所述电极延伸部延伸到第一电极结构的电极和第二电极结构的相对电极之间限定的空腔。通过对第一电极结构和第二电极结构施加电压将电极静电地吸引到相对电极以将电极延伸部按压在空腔内,第一电极结构和第二电极结构可以布置在承载状态。电极延伸部和限定空腔的接合表面之间的摩擦防止电极延伸部在空腔内滑动,从而响应于施加负载到可变强化装置而维持第一电极结构和第二电极结构的部件之间的结构关系。(The present disclosure relates to a variable reinforcement device including a first electrode structure and a second electrode structure. The first electrode structure includes an electrode extension that extends to a cavity defined between an electrode of the first electrode structure and an opposing electrode of the second electrode structure. The first and second electrode structures may be arranged in a loaded state by applying a voltage to the first and second electrode structures to electrostatically attract the electrodes to the opposing electrode to press the electrode extension within the cavity. Friction between the electrode extension and the engagement surface defining the cavity prevents the electrode extension from sliding within the cavity, thereby maintaining a structural relationship between components of the first electrode structure and the second electrode structure in response to applying a load to the variable reinforcement device.)

1. A variable stiffening device, the variable stiffening device comprising:

a first electrode structure comprising a first support structure and a plurality of first electrodes extending from the first support structure, the plurality of first electrodes comprising first electrodes and second electrodes, wherein the first electrode structure further comprises a first electrode extension extending from the second electrode; and

a second electrode structure comprising a second support structure and a plurality of second electrodes extending from the second support structure, the plurality of second electrodes comprising a first opposing electrode opposing the first electrode to form a cavity between a bonding surface of the first electrode and a bonding surface of the first opposing electrode, wherein:

the first electrode extension extends from the second electrode into a cavity formed by the first electrode and the first opposing electrode such that when a voltage is applied to the first electrode structure and the second electrode structure, the first electrode extension is sandwiched between the first electrode and the first opposing electrode such that the first electrode extension is held in the cavity via the bonding surface to maintain a structural relationship between the first electrode and the second electrode to support the first support structure.

2. The variable stiffening device of claim 1, wherein the first and second support structures comprise a planar sheet, wherein the plurality of first electrodes are coplanar with the first support structure and the plurality of second electrodes are coplanar with the second support structure when the first and second electrode structures are in the unloaded state.

3. The variable reinforcement device of claim 2, wherein the plurality of first electrodes and the plurality of second electrodes are angled relative to the first support structure and the second support structure when the first electrode structure and the second electrode structure are in the loaded state such that support ends of the plurality of first electrodes and the plurality of second electrodes support the first support structure and the second support structure in the loaded position.

4. The variable stiffening device of claim 1, wherein the first support structure is arranged on the second support structure such that the plurality of first electrodes is aligned with the plurality of second electrodes.

5. The variable stiffening device of claim 4, wherein:

the plurality of first electrodes further includes a third electrode and a fourth electrode extending from the first support structure;

the plurality of second electrodes further comprises a second counter electrode, a third counter electrode, and a fourth counter electrode extending from the second support structure;

the first electrode and the first counter electrode are aligned with each other to form a first cavity between the bonding surface of the first electrode and the bonding surface of the first counter electrode;

the second electrode and the second opposing electrode are aligned with each other to form a second cavity between the bonding surface of the second electrode and the bonding surface of the second opposing electrode;

the third electrode and the third counter electrode are aligned with each other to form a third cavity between the bonding surface of the third electrode and the bonding surface of the third counter electrode; and

the fourth electrode and the fourth counter electrode are aligned with each other to form a fourth cavity between the bonding surface of the fourth electrode and the bonding surface of the fourth counter electrode.

6. The variable stiffening device of claim 5, wherein:

the first electrode structure further includes a second electrode extension extending from the first electrode and inserted into the fourth cavity, a third electrode extension extending from the fourth electrode and inserted into the third cavity, and a fourth electrode extension extending from the second electrode into the second cavity; and

when a voltage is applied to the first electrode structure and the second electrode structure, the first electrode extension is sandwiched and held in the first cavity, the second electrode extension is sandwiched and held in the fourth cavity, the third electrode extension is sandwiched and held in the third cavity, and the fourth electrode extension is sandwiched and held in the second cavity.

7. The variable stiffening device of claim 4, wherein the variable stiffening device maintains a cube-like shape when a voltage is applied to the first and second electrode structures and a load is placed on the first or second support structure.

8. The variable reinforcement device of claim 1, wherein the first electrode structure comprises a first layer of electrode material and the second electrode structure comprises a second layer of electrode material.

9. The variable reinforcement device of claim 8, wherein the first layer of electrode material and the second layer of electrode material comprise aluminum-coated biaxially oriented polyethylene terephthalate.

10. The variable reinforcement device of claim 8, wherein the first and second layers of electrode material extend continuously across the first and second electrode structures.

11. The variable reinforcement device of claim 8, wherein the first electrode structure comprises a first structural layer supporting a first layer of electrode material and the second electrode structure comprises a second structural layer supporting a second layer of electrode material.

12. The variable reinforcement device of claim 11, wherein the first structural layer comprises a flexible joint between the first support structure and the plurality of first electrodes, and the second structural layer comprises a flexible joint between the second support structure and the plurality of second electrodes.

13. The variable reinforcement device of claim 1, wherein the bonding surface comprises an adhesive layer disposed on the first electrode and the first opposing electrode.

14. A variable stiffening device, the variable stiffening device comprising:

a plurality of electrode pairs extending from the support structure, each electrode pair including an electrode rotatably coupled to the support structure, an opposing electrode, and a cavity defined between a bonding surface of the electrode and a bonding surface of the opposing electrode;

a plurality of electrode extensions, wherein each electrode extension of the plurality of electrode extensions comprises a first end attached to a first electrode of one of the plurality of electrode pairs and a free end disposed proximate to an adjacent one of the plurality of electrode pairs, wherein the free end of each electrode extension is inserted into a cavity defined by the adjacent one of the plurality of electrode pairs; and

a voltage source coupled to each of the plurality of electrode pairs, wherein when a voltage difference provided via the voltage source is present in each electrode pair, each electrode extension is sandwiched in a cavity defined by the engagement surfaces of an adjacent pair of the plurality of electrode pairs, and the electrode extensions are retained in the cavity by the engagement surfaces to maintain a structural relationship between the plurality of electrode pairs to support the support structure in a load-bearing state.

15. The variable stiffening device of claim 14, wherein:

the electrodes of the plurality of electrode pairs are rotatably coupled to the first portion of the support structure via flexible joints formed in a structural support layer that extends over the first portion of the support structure and each electrode of the plurality of electrode pairs; and

opposing electrodes of the plurality of electrode pairs are rotatably coupled to a second portion of the support structure that is attached to an underside surface of the first portion of the support structure.

16. The variable reinforcement device of claim 14, wherein the support structure is a parallelogram and each of the plurality of electrode pairs extends from an edge of the support structure such that when the support structure is placed in a load-bearing position, the variable reinforcement device is substantially parallelogram-shaped and the support structure defines a load-bearing surface for supporting a load that is at least about 50 times the weight of the variable reinforcement device.

17. The variable reinforcement device of claim 14, wherein the engagement surface defining each cavity includes an attachment member that engages one of the plurality of electrode extensions to retain the electrode extension in the cavity.

18. A method of actuating a variable stiffening device, the method comprising:

inserting an electrode extension of a first electrode coupled to a support structure into a cavity defined between two engagement surfaces of an electrode pair coupled to the support structure;

generating a voltage using a voltage source electrically coupled to the pair of electrodes; and

a voltage generated by a voltage source is applied to the pair of electrodes, thereby electrostatically drawing the electrodes of the pair of electrodes together such that the position of the electrode extension in the cavity is maintained via contact between the electrode extension and the engagement surface to maintain a structural relationship between the first electrode and the pair of electrodes, thereby holding the support structure in the load-bearing position.

19. The method of claim 18, further comprising moving the first electrode and the electrode pair from the unloaded state by rotating the first electrode and the electrode pair about a flexible joint formed between the first electrode and the electrode pair and the support structure while inserting the electrode extension into the cavity.

20. The method of claim 18, wherein the engagement surface includes an attachment element that engages the electrode extension to maintain the position of the electrode extension in the cavity.

Technical Field

The present description relates generally to a variable stiffening device and, more particularly, to a variable stiffening device including an electrode structure that compresses an electrode extension to maintain the shape of a deformed structure.

Background

Current variable stiffening devices use various techniques to provide a device that can be actuated between a less stiff state and a more stiff state. These variable augmentation devices are actuated based on the application of an external stimulus, such as a temperature change or a pressure change. Some example variable augmentation devices use an external vacuum to compress the various layers of the device to place the device in a more rigid state. However, the external vacuum requires cumbersome equipment and is inefficient to operate.

Accordingly, there is a need for an improved variable stiffening device that is smaller in profile and operates on demand.

Disclosure of Invention

In one embodiment, the variable reinforcement device includes a first electrode structure including a first support structure and a plurality of first electrodes extending from the first support structure, the plurality of first electrodes including a first electrode and a second electrode, wherein the first electrode structure further includes a first electrode extension extending from the second electrode. The variable stiffening device further includes a second electrode structure including a second support structure and a plurality of second electrodes extending from the second support structure, the plurality of second electrodes including a first opposing electrode opposing the first electrode to form a cavity between a bonding surface of the first electrode and a bonding surface of the first opposing electrode. The first electrode extension extends from the second electrode into a cavity formed by the first electrode and the first opposing electrode such that when a voltage is applied to the first electrode structure and the second electrode structure, the first electrode extension is sandwiched between the first electrode and the first opposing electrode such that the first electrode extension is held in the cavity via the bonding surface to maintain a structural relationship between the first electrode and the second electrode to support the first support structure.

In another embodiment, the variable stiffening device includes a plurality of electrode pairs extending from the support structure, each electrode pair including an electrode rotatably coupled to the support structure, an opposing electrode, and a cavity defined between a bonding surface of the electrode and a bonding surface of the opposing electrode. The variable reinforcement device also includes a plurality of electrode extensions, each electrode extension including a first end attached to a first electrode of one of the plurality of electrode pairs and a free end disposed proximate an adjacent one of the plurality of electrode pairs. The free end of each electrode extension is inserted into a cavity defined by an adjacent one of the plurality of electrode pairs. A voltage source is coupled to each of the plurality of electrode pairs. When a voltage difference provided via a voltage source is present in each electrode pair, each electrode extension is sandwiched in a cavity defined by the engaging surfaces of an adjacent pair of the plurality of electrode pairs, and the electrode extensions are held in the cavity by the engaging surfaces to maintain a structural relationship between the plurality of electrode pairs to support the support structure in a load-bearing state.

In another embodiment, a method of actuating a variable reinforcement device includes inserting an electrode extension of a first electrode coupled to a support structure into a cavity defined between two engagement surfaces of an electrode pair coupled to the support structure. The method also includes generating a voltage using a voltage source electrically coupled to the pair of electrodes. The method further includes applying a voltage generated by a voltage source to the pair of electrodes, thereby electrostatically drawing the electrodes of the pair of electrodes together such that the position of the electrode extension in the cavity is maintained via contact between the electrode extension and the engagement surface to maintain a structural relationship between the first electrode and the pair of electrodes, thereby holding the support structure in the load-bearing position.

These and other features provided by the embodiments described herein will be more fully understood in view of the following detailed description, taken in conjunction with the accompanying drawings.

Drawings

The embodiments set forth in the drawings are illustrative and exemplary in nature and not intended to limit the subject matter defined by the claims. The following detailed description of illustrative embodiments can be understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals, and in which:

fig. 1A depicts an exploded view of a variable reinforcement device according to one or more embodiments shown and described herein.

Fig. 1B depicts a top view of the variable stiffening device shown in fig. 1A in a non-loaded state according to one or more embodiments shown and described herein.

Fig. 1C schematically depicts a cross-sectional view of an electrode structure of the variable reinforcement device through line I-I shown in fig. 1B, according to one or more embodiments shown and described herein.

FIG. 2 depicts a perspective view of the variable reinforcement device shown in FIG. 1A in a loaded state, according to one or more embodiments described herein; and

fig. 3 depicts a cross-sectional view of an electrode structure of the variable reinforcement device through line III-III shown in fig. 1B according to one or more embodiments described herein.

Detailed Description

Referring generally to the drawings, embodiments of the present disclosure are directed to a variable reinforcement device that is configurable between a non-load bearing state and a load bearing state by inserting an electrode extension into a cavity defined between electrode structures and applying a voltage to the electrode structures to clamp the electrode extension within the cavity. In an embodiment, the electrodes of each electrode structure have opposing engagement surfaces defining a cavity, wherein each engagement surface has an attachment element that engages an electrode extension inserted into the cavity when a voltage is applied. Friction between the electrode extension and the attachment element engaging the electrode extension maintains the structural relationship between the electrodes with shear forces in the electrode extension to maintain the variable reinforcement device in a load bearing state.

Referring now to fig. 1A, 1B and 1C, a variable stiffening device 100 is schematically depicted. The variable stiffening device 100 includes a first electrode structure 102 and a second electrode structure 104. As depicted in fig. 1C, in an embodiment, the first electrode structure 102 is disposed on and in contact with the second electrode structure 104. In an embodiment, the first electrode structure 102 and the second electrode structure 104 are similar in size such that when the first electrode structure 102 is disposed on and aligned with the second electrode structure 104, the first electrode structure 102 completely covers the second electrode structure 104.

As depicted in fig. 1A and 1B, the first electrode structure 102 includes a plurality of electrodes 108, 110, 112, and 114 extending from the first support structure 106. The second electrode structure 104 includes a plurality of opposing electrodes 140, 142, 144, and 146 extending from the second support structure 138. In an embodiment, the plurality of electrodes 110, 112, 114, and 116 are movable relative to the first support structure 106. For example, as depicted in fig. 1C, the electrode 110 is coupled to the first support structure 106 by a flexible joint 178 having a greater flexibility than the first support structure 106 and the electrode 110. In an embodiment, the flexible joint 178 is composed of a layer of material (e.g., the structural layer 310 described herein with respect to fig. 3) that extends throughout the first electrode structure 102. For example, in an embodiment, the flexible joint 178 may be formed by laser patterning or ablating a layer of material such that the thickness of the layer of material within the flexible joint 178 is reduced compared to the remainder of the first electrode structure 102, so as to provide flexibility at the flexible joint 178 to facilitate movement of the first electrode structure 102 from a non-load bearing state to a load bearing state, as described herein. It should be understood that the first electrode 108, the third electrode 112, and the fourth electrode 114 may be coupled to the first support structure 106 via a flexible joint similar to the flexible joint 178.

In an embodiment, the plurality of opposing electrodes 140, 142, 144, and 146 are also movable relative to the second support structure 138. In various embodiments, the second electrode structure 104 has a similar cross-sectional layer structure as the first electrode structure 102 described herein. For example, as depicted in fig. 1C, the second electrode 142 is coupled to the second support structure 138 via a flexible joint 176, which may be similar in structure to the flexible joint 178 described herein. It should be appreciated that the opposing electrodes 140, 144, and 146 may be coupled to the second support structure 138 via a flexible joint similar to flexible joint 176. The flexible joints 176 and 178 coupling the electrodes of the first and second electrode structures 102 and 104 to the first and second support structures 106 and 138 beneficially allow the first and second electrode structures 102 and 104 to move from a non-load bearing state to a load bearing state.

Fig. 1A depicts an exploded view of the first electrode structure 102 and the second electrode structure 104 in a non-load bearing state. In the depicted embodiment, the first support structure 106 and the second support structure 138 are planar sheets (e.g., extending in the X-Y plane depicted in fig. 1A). The first electrode 108, the second electrode 110, the third electrode 112, and the fourth electrode 114 are coplanar with the first support structure 106 (or extend parallel to the first support structure 106) when the first electrode structure 102 is in a non-load bearing state. When the second electrode structure 104 is in a non-load bearing state, the opposing first, second, third and fourth electrodes 140, 142, 144, 146 are coplanar with the second support structure 138. In an embodiment, the first electrode structure 102 and the second electrode structure 104 extend parallel to each other when the first electrode structure 102 and the second electrode structure 104 are in a non-load bearing state.

In an embodiment, to move the first electrode structure 102 and the second electrode structure 104 to the loaded state, the plurality of electrodes 108, 110, 112, and 114 are moved (e.g., via folding the flexible joint 178 described with respect to fig. 1C) in a downward direction (e.g., -Z direction depicted in fig. 1A) relative to the first support structure 106 such that the plurality of electrodes 108, 110, 112, and 114 are no longer coplanar with the first support structure 106, but extend at an angle θ relative to the first support structure 106 (see fig. 1C). The plurality of opposing electrodes 140, 142, 144, and 146 may move relative to the second support structure 138 in a similar manner. In other words, the electrodes of the first electrode structure 102 and the second electrode structure 104 are uniformly movable with respect to the first support structure 106 and the second support structure 138. In the depicted embodiment, the electrodes 108, 110, 112, 140, 142, 144, and 146 of the first and second electrode structures 102 and 104, respectively, are identical in shape and are arranged in a similar manner with respect to the first and second support structures 106 and 138. Such a configuration is advantageous for providing a uniform load distribution and balanced configuration, but various alternative embodiments are also contemplated in which the electrodes 108, 110, 112, 140, 142, 144, and 146 may have different dimensions and directions of extension.

In an embodiment, the first support structure 106 and the second support structure 138 are each a parallelogram (e.g., square), and the electrodes 108, 110, 112, 140, 142, 144, and 146 of the first electrode structure 102 and the second electrode structure 104 are each coupled to and extend from an edge of the first support structure 106 or an edge of the second support structure 138. In an embodiment, electrodes 108, 110, 112, and 114 each have the same dimensions (e.g., length and width) as first support structure 106, and electrodes 140, 142, 144, and 146 each have the same dimensions as second support structure 138. When so sized, the first electrode structure 102 and the second electrode structure 104 may be folded into a substantially cubic, load bearing state, as described with respect to fig. 2. It should be understood that various alternative dimensional configurations are contemplated for the first electrode structure 102 and the second electrode structure 104. For example, in an embodiment, the electrode 110 may be different in size than the electrode 112 such that the first support structure 106 is tilted when arranged in the load-bearing state. It should be understood that the dimensions of the electrodes may be customized as needed for any particular oriented application of the first support structure 106.

As depicted in fig. 1A, the first electrode structure 102 includes a first electrode extension 116, a second electrode extension 118, a third electrode extension 120, and a fourth electrode extension 122. In an embodiment, the first electrode extension 116, the second electrode extension 118, the third electrode extension 120, and the fourth electrode extension 122 are comprised of a layer of material that also extends through the plurality of electrodes 108, 110, 112, and 114 (e.g., the electrode layer 308 described herein with respect to fig. 3). In an embodiment, each of the first electrode extension 116, the second electrode extension 118, the third electrode extension 120, and the fourth electrode extension 122 includes a first end that extends directly from one of the plurality of electrodes 108, 110, 112, and 114 and a free end that is disposed proximate an adjacent one of the plurality of electrodes 108, 110, 112, and 114. For example, the first electrode extension 116 includes a first end 124 extending from the electrode 108 (e.g., the electrode layer extends continuously from the electrode 108 to the first electrode extension 116) and a free end 123 disposed proximate to the electrode 110. The free end 123 is not directly attached to the electrode 110, but is movable relative to the electrode 110. The second electrode extension 118 includes a first end 128 extending from the second electrode 110 and a free end 126 disposed proximate the electrode 112. The third electrode extension 120 includes a first end 132 extending from the electrode 112 and a free end 130 disposed proximate to the electrode 114. The fourth electrode extension 122 includes a first end 136 extending from the electrode 114 and a free end 134 disposed proximate the electrode 108.

The first electrode extension 116, the second electrode extension 118, the third electrode extension 120, and the fourth electrode extension 122 include free ends 123, 126, 130, and 134 that are movable relative to the first electrode structure 102 to facilitate adjusting the variable reinforcement device 100 from the non-load bearing state depicted in fig. 1A to the load bearing state. As depicted in fig. 1A and 1B, the first electrode structure 102 and the second electrode structure 104 may be arranged relative to each other such that the plurality of electrodes 108, 110, 112, and 114 are aligned relative to the plurality of opposing electrodes 140, 142, 144, and 146. Thus, electrode 108 may be disposed on and overlap opposing electrode 140 to form first cavity 152, electrode 110 may be disposed on and overlap opposing electrode 142 to form second cavity 154, electrode 112 may be disposed on and overlap opposing electrode 144 to form third cavity 156, and electrode 114 may be disposed on and overlap opposing electrode 146 to form fourth cavity 158. In an embodiment, each of the first electrode extension 116, the second electrode extension 118, the third electrode extension 120, and the fourth electrode extension 122 is inserted into one of the first cavity 152, the second cavity 154, the third cavity 156, and the fourth cavity 158 when the plurality of electrodes 108, 110, 112, and 114 and the plurality of opposing electrodes 140, 142, 144, and 146 are moved relative to the first support structure 106 and the second support structure 138 to place the variable reinforcement device 100 in a load-bearing state.

For example, as depicted in fig. 1C, when the electrode 110 is folded at the flexible joint 178 such that the electrode 110 extends at an angle θ relative to the first support structure 106, the first electrode extension 116 is inserted into the second cavity 154 formed between the electrode 110 and the opposing electrode 142. The second cavity 154 is formed between a bonding surface 166 of the opposing electrode 142 and a bonding surface 168 of the electrode 110. As the electrode 110 and the opposing electrode 142 are folded about the flexible joints 178 and 176, the free end 123 of the electrode extension 116 travels through the second cavity 154. In view of this, the amount of movement (e.g., the value of the angle θ) of the electrode 110 and the opposing electrode 142 determines the extent to which the electrode extension 116 is disposed within the second cavity 154. As depicted in fig. 1A, the electrode extensions 116 are arcuate tabs that substantially fully extend the distance between the electrodes 108 and 110. Shaping the electrode extension 116 as an arc-shaped tab advantageously avoids the electrode extension 116 from protruding from the second cavity 154 when the variable reinforcement device 100 is arranged in the load-bearing state. Further, the length of the electrode extension 116 (e.g., extending the entire length between the electrode 108 and the electrode 110) advantageously maximizes the amount of the electrode extension 116 that extends into the second cavity 154, thereby maximizing the contact area between the electrode extension 116 and the bonding surfaces 166, 168.

It should be understood that alternative configurations for the electrode extension 116 are contemplated. For example, in an embodiment, the first electrode extension 116, the second electrode extension 118, the third electrode extension 120, and the fourth electrode extension 122 may not be formed as arcuate tabs. For example, in an embodiment, the first electrode extension 116, the second electrode extension 118, the third electrode extension 120, and the fourth electrode extension 122 may include substantially straight linear segments extending from a first one of the plurality of electrodes 108, 110, 112, and 114 to an adjacent one of the plurality of electrodes 108, 110, 112, and 114. In an embodiment, the first electrode extension 116, the second electrode extension 118, the third electrode extension 120, and the fourth electrode extension 122 may turn or change direction as they extend between the plurality of electrodes 108, 110, 112, and 114. In an embodiment, each of the first electrode extension 116, the second electrode extension 118, the third electrode extension 120, and the fourth electrode extension 122 may not extend the entire distance between pairs of the plurality of electrodes 108, 110, 112, and 114, but only a portion of the distance between the pairs of electrodes. Any size or shape of first electrode extension 116, second electrode extension 118, third electrode extension 120, and fourth electrode extension 122 that is compatible with insertion of the electrode extensions into the cavities formed via the electrodes of first electrode structure 102 and the opposing electrodes of second electrode structure 104 may be used consistent with the present disclosure.

As depicted in fig. 1C, engagement surface 166 of opposing electrode 142 includes an attachment element 172, while engagement surface 168 of electrode 110 includes an attachment element 174. In an embodiment, the first electrode structure 102 and the second electrode structure 104 may each be attached to a voltage source (not depicted) such that the first electrode structure 102 and the second electrode structure 104 receive voltages having opposite polarities. The opposite polarity electrostatically attracts the electrode 110 and the opposing electrode 142 such that the bonding surfaces 166 and 168 press against the first electrode extension 116 within the second cavity 154. The attachment members 172 and 174 may engage the first electrode extension 116 to create friction between the engagement surfaces 166 and 168 and the first electrode extension 116. Such friction may prevent the first electrode extension 116 from moving within the second cavity 154 in the presence of an external force (e.g., from a load disposed on the first support structure 106). Thus, when a voltage is applied to first electrode structure 102 and second electrode structure 104, the friction provided via traction elements 172 and 174 facilitates maintaining a structural relationship between electrodes 108 and 110 (e.g., when variable reinforcement device 100 is placed in a loaded state).

The attachment members 172 and 174 can take a variety of different forms depending on the embodiment. For example, in an embodiment, attachment elements 172 and 174 are attachment layers (e.g., attachment layers 326 and 328 comprising polypropylene tape, and described with respect to fig. 3) that extend across engagement surfaces 166 and 168. In an embodiment, the attachment members 172 and 174 are roughening members. For example, the engagement surfaces 166 and 168 can include a textured pattern that overlaps the first electrode extension 116 and serves as attachment elements 172 and 174. In an embodiment, the first electrode extension 116 may include attachment elements (e.g., attachment layers 326 and 328 described with respect to fig. 3) that engage the attachment elements 172 and 174 when the first electrode extension 116 is squeezed within the second cavity 154 when a voltage is applied to the first electrode structure 102 and the second electrode structure 104.

Still referring to fig. 1C, in an embodiment, a sealing element 160 is disposed between the electrode 110 and the opposing electrode 142. The sealing element 160 may seal the second cavity 154 to prevent external debris from entering the second cavity 154 and disrupting the operation of the variable reinforcement device 100. The sealing element 160 may be disposed at the ends of the electrode 110 and the opposing electrode 142 opposite the flexible joints 178 and 176, respectively. In an embodiment, sealing member 160 includes an attachment member extending between engagement surfaces 166 and 168. In an embodiment, the sealing element 160 may guide the first electrode extension 116 through the second cavity 154 as the electrode extension 116 travels through the second cavity 154 when the first electrode structure 102 and the second electrode structure 104 are adjusted from the non-load bearing state depicted in fig. 1A. In an embodiment, the engagement surfaces 166 and 168 may include grooves or channels (not depicted) shaped in a corresponding manner to the outer surface of the first electrode extension 116 such that the engagement surfaces 166 and 168 guide the first electrode extension 116 through the second cavity 154.

Although the second cavity 154 between the electrode 110 and the opposing electrode 142 is described with respect to fig. 1C only, it should be understood that the cavities formed between other pairs of electrodes between the plurality of electrodes 108, 110, 112, and 114 and the plurality of opposing electrodes 140, 142, 144, and 146 may have a similar structure as the second cavity 154. For example, a first cavity 152 formed between the electrode 108 and the opposing electrode 140 may receive the fourth electrode extension 122 and have a similar structure as the second cavity 154. A third cavity 156 formed between the electrode 112 and the opposing electrode 144 may receive the second electrode extension 118 and have a structure similar to the second cavity 154. A fourth cavity 158 formed between the electrode 114 and the opposing electrode 146 may receive the third electrode extension 120 and have a similar structure to the second cavity 154.

Referring to fig. 1A and 1B, although the first electrode structure 102 and the second electrode structure 104 are described herein as each including four electrodes, it should be understood that alternative embodiments including fewer or more electrodes are contemplated. In an example, the first electrode structure 102 may include only the electrodes 108 and 110 and the first electrode extension 116, while the second electrode structure 104 may include only one of the opposing electrodes 140 and 142 (e.g., to form a cavity for insertion of the first electrode extension 116). Further, not every electrode of the first electrode structure 102 may have an electrode extension extending therefrom. For example, in an embodiment, the first electrode structure 102 may include only the first electrode extension 116 and the third electrode extension 120.

In embodiments, the electrode extensions may not all be included in a single electrode structure. For example, in an embodiment, the first electrode structure 102 includes a first electrode extension 116 and a second electrode extension 118 (e.g., the first electrode extension 116 and the second electrode extension 118 may extend directly from an electrode of the first electrode structure 102, as described herein), while the second electrode structure 104 includes a third electrode extension 120 and a fourth electrode extension 122. Furthermore, alternative embodiments of the variable stiffening device 100 may include first and second electrode structures 102, 104 that differ from each other in shape. For example, in an embodiment, the first electrode structure 102 (and the plurality of electrodes 108, 110, 112, and 114) is larger in size than the second electrode structure 104 such that the cavity formed between the electrode and the opposing electrode is displaced from the end of the variable reinforcement device 100. Electrode structures having various dimensional relationships, distributions of electrodes, support structure configurations, and arrangements of electrode extensions may all be used consistent with the present disclosure.

Referring to fig. 1B, in an embodiment, the first electrode structure 102 and the second electrode structure 104 may have weight-reducing features for reducing the weight of the variable reinforcement device 100 and removing unnecessary material therefrom. For example, in an embodiment, the first and second support structures each include structural layers (e.g., structural layers 310 and 318 described herein with respect to fig. 3) that are patterned to reduce the weight of the variable stiffening device 100. As depicted in fig. 1B, each of the plurality of electrodes 108, 110, 112, and 114 of the first electrode structure 102 includes two elongated cavities 148 extending near its outer edges and a circular cavity 150 disposed in a central region thereof. In contrast to the plurality of electrodes 108, 110, 112, and 114, the first support structure 106 includes a plurality of circular cavities 150. The first support structure 106 may not include the elongated cavity 148 to provide rigid structural support for loads placed thereon. In an embodiment, the second electrode structure 104 includes a set of similar weight-reducing features. In an embodiment, neither the first electrode structure 102 nor the second electrode structure 104 includes weight-reduction features to provide maximum structural support. As should be appreciated, the number and arrangement of weight-reduction features incorporated into the variable reinforcement device 100 may depend on the required load-bearing capacity, the materials used to construct the first and second electrode structures 102, 104, the size and arrangement of the first and second electrode structures 102, 104, and the voltage to be applied to the first and second electrode structures 102, 104. Thus, any number and arrangement of weight reduction features may be incorporated into a variable stiffening device 100 consistent with the present disclosure.

Referring now to FIG. 2, a perspective view of the variable stiffening device 100 in a load-bearing state is depicted. The electrodes 108 and 114 are folded (e.g., around a flexible joint similar to the flexible joint 178 described herein with respect to fig. 1C) such that the electrodes 108 and 114 are substantially perpendicular to the first support structure 106 (e.g., the angle θ described with respect to fig. 1C is about 80 degrees to about 100 degrees). In an embodiment, support end 202 of electrode 114 and support end 204 of electrode 108 are disposed on a surface (e.g., a table, a floor, or any support). In the angular configuration depicted, the electrodes 108 and 114 support the first support structure 106 in a position above the surface in the loaded state.

The fourth electrode extension 122 extends behind the electrode 108 into the first cavity 152 formed between the electrode 108 and the opposing electrode 140 depicted in fig. 1B. As described herein, electrode 108 and opposing electrode 140 may include engaging surfaces that define first cavity 152 and include an attachment element that engages fourth electrode extension 122 when a voltage from a voltage source is supplied to variable reinforcement device 100. For example, voltages of opposite polarities may be applied to the first and second electrode structures 102, 104 to cause electrostatic attraction between the electrode 108 and the opposing electrode 140 to engage the engagement surface defining the cavity with the fourth electrode extension 122 at the attachment element. Friction between the fourth electrode extension 122 and the attachment member maintains the positioning of the fourth electrode extension 122 within the first cavity 152 and the structural relationship between the electrode 108 and the electrode 114 such that the first support structure 106 remains supported via the support ends 202 and 204. It should be appreciated that the first, second, and third electrode extensions 116, 118, and 118 may be retained in a cavity defined by the electrode pair of the first electrode structure 102 and the second electrode structure 104 in a similar manner to retain the variable reinforcement device 100 in a load-bearing state.

As depicted in fig. 2, a load 200 is disposed on the first support structure 106. In an embodiment, friction between the first electrode extension 116, the second electrode extension 118, the third electrode extension 120, and the fourth electrode extension 122 and the engagement surfaces defining the cavity in which the electrode extensions are disposed is sufficient to prevent the first electrode extension 116, the second electrode extension 118, the third electrode extension 120, and the fourth electrode extension 122 from slipping, even when the load 200 is disposed on the first support structure. In one example, the variable reinforcement device 100 is configured to weigh about 20 grams and be able to maintain a load bearing state using 10kV voltage even when an about 1Kg load 200 is disposed on the first support structure 106. Thus, in this example, variable reinforcement device 100 is capable of maintaining at least about 50 times its own weight.

FIG. 3 depicts an example cross-sectional view of the variable stiffening device at line III-III depicted in FIG. 1B. In an embodiment, the cross-sectional view depicted in fig. 3 is a cross-sectional view of the variable stiffening device 100 in the unloaded state described with respect to fig. 1A and 1B. Thus, the first electrode structure 102 may extend in a first plane, while the second electrode structure 104 may extend in a second plane (e.g., the angle θ described with respect to fig. 1C may be about 0 degrees).

Fig. 3 depicts a cross-sectional view of a third cavity 156 formed between the electrode 112 of the first electrode structure 102 and the opposing electrode 144 of the second electrode structure 104. Electrode 112 includes an electrode layer 308, a structural layer 310, a protective layer 312, and an adhesive layer 314. The electrode layer 308 may be a layer of conductive material adapted to receive a voltage from a voltage source. In an embodiment, the electrode layer 308 is constructed of aluminum coated Mylar (e.g., biaxially oriented polyethylene terephthalate). Mylar advantageously provides relatively high tensile strength and dimensional stability. As depicted in fig. 3, electrode layer 308 extends from electrode 112 into electrode extension 120 via first end 132. Mylar provides tensile strength to the third electrode extension 120 so that the third electrode extension 120 does not break when the variable reinforcement device 100 is placed in a load bearing state as described herein. In an embodiment, the electrode layer 308 extends over the entire extent of the first electrode structure 102 described herein.

Structural layer 310 provides structural support to electrode layer 308 so that variable stiffening device 100 can maintain structure despite the relatively heavy load placed on the variable stiffening device. In an embodiment, the structural layer 310 is arranged in direct contact with the electrode layer 308. Structural layer 310 may include polycarbonate for durability, strength, and moldability. In the depicted example, the structural layer 310 does not extend into the third electrode extension 120 to enhance the flexibility of the third electrode extension 120 to be guided into the fourth cavity 158 described herein with respect to fig. 1B. Protective layer 312 may provide environmental resistance (e.g., moisture resistance) and fatigue resistance to structural layer 310. In an embodiment, the protective layer 312 is composed of biaxially oriented polypropylene (BOPP). An adhesive layer 314 is disposed on the opposite side of the electrode layer 308 from the structural layer 310. The adhesive layer 314 defines an engagement surface 304, the engagement surface 304 delimiting one side of the third cavity 156. In an embodiment, the adhesive layer 314 is comprised of BOPP tape and acrylic adhesive to provide an attachment element that engages the second electrode extension 118.

The opposing electrode 144 includes an electrode layer 316, a structural layer 318, a protective layer 320, and an adhesive layer 322. In an embodiment, opposing electrode 144 has a structure similar to electrode 112. As shown, electrode layers 306 and 316 are arranged such that adhesive layers 312 and 322 are the only material separating electrode layers 306 and 316. Such an arrangement provides a minimum distance separating electrode layers 306 and 316 when electrode layers 306 and 316 are attracted to each other and contact each other in response to a voltage applied to variable reinforcement device 100. Such a minimum distance maximizes the attractive force between the electrode 112 and the opposing electrode 144, thereby maximizing the resistance of the second electrode extension 118 to sliding off of the third cavity 156 when the variable reinforcement device is in a loaded state.

The free end 126 of the second electrode extension 118 is shown disposed in the third cavity 156. In an embodiment, as the positioning of the electrode 112 and the opposing electrode 144 is adjusted, the free end 126 is further inserted into the cavity 156 to increase the amount of overlap between the second electrode extension 118 and the engagement surfaces 302 and 304 of the electrode 112 and the opposing electrode 144. Upon application of a voltage to variable reinforcement device 100, electrode 112 is electrostatically attracted to opposing electrode 144 such that second electrode extension 118 is pressed against both engagement surfaces 302 and 304. The adhesive in the adhesive layers 312 and 322 provides friction to prevent the second electrode extension 118 from sliding within the third cavity 156 upon application of a voltage.

In the depicted example, both the second electrode extension 118 and the third electrode extension 120 include adhesive layers 326 and 328 disposed on either side of the electrode layer 308. In an embodiment, adhesive layers 326 and 328 are constructed of BOPP tape with acrylic adhesive. Adhesive layers 326 and 328 increase the friction between second electrode extension 118 and bonding surfaces 302 and 304 to beneficially increase the strength of variable reinforcement device 100 when placed in the load bearing state described herein. Adhesive layer 326 may be applied to electrode layer 308 at the same time as adhesive layer 312.

It should now be understood that the embodiments described herein are directed to a variable reinforcement device including a first electrode structure and a second electrode structure. The first electrode structure includes an electrode extension extending to a cavity defined between an electrode of the first electrode structure and an opposing electrode of the second electrode structure. The first and second electrode structures may be arranged in a load-bearing state by applying a voltage to the first and second electrode structures to electrostatically attract the electrodes to the opposing electrodes to press the electrode extensions within the cavities. Friction between the electrode extension and the engagement surface defining the cavity prevents the electrode extension from sliding within the cavity, thereby maintaining the structural relationship between the components of the first electrode structure and the second electrode structure in response to application of a load to the variable reinforcement device.

It should be noted that the terms "substantially" and "approximately" may be utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. These terms are also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the related subject matter.

Although specific embodiments have been illustrated and described herein, it should be understood that various other changes and modifications can be made without departing from the spirit and scope of the claimed subject matter. Moreover, although various aspects of the claimed subject matter have been described herein, these aspects need not be used in combination. It is therefore intended that the following appended claims cover all such variations and modifications that are within the scope of the claimed subject matter.