Artificial muscle stacks comprising alternatingly offset artificial muscle layers

1. An artificial muscle stack comprising:

a plurality of artificial muscle layers, wherein each artificial muscle layer comprises one or more artificial muscles, the one or more artificial muscles comprising:

a housing comprising an electrode region and an expandable fluid region;

a dielectric fluid housed within the housing; and

an electrode pair comprising a first electrode and a second electrode positioned in the electrode region of the housing, wherein:

the first electrode and the second electrode each comprise two or more tab portions and two or more bridge portions;

each of the two or more bridge portions interconnects adjacent tab portions; and

at least one of the first electrode and the second electrode comprises a central opening positioned between the two or more tab portions and encircling the expandable fluid region; and

wherein the plurality of artificial muscle layers are arranged such that the expandable fluid region of the one or more artificial muscles of each artificial muscle layer overlaps at least one tab portion of one or more artificial muscles of an adjacent artificial muscle layer.

2. The artificial muscle stack of claim 1 , wherein adjacent artificial muscle layers are offset from one another along one or more tab axes, each tab axis extending from a center axis of the expandable fluid region of an individual artificial muscle of the plurality of artificial muscle layers to an end of at least one of the two or more tab portions of the individual artificial muscle of the plurality of artificial muscle layers.

3. The artificial muscle stack of claim 2 , wherein the plurality of artificial muscle layers comprise at least three artificial muscle layers and each inner artificial muscle layer is offset a first adjacent artificial muscle layer along a first tab axis and offset a second adjacent artificial muscle layer along a second tab axis.

4. The artificial muscle stack of claim 3 , wherein the first tab axis is orthogonal the second tab axis.

5. The artificial muscle stack of claim 1 , wherein:

at least one of the plurality of artificial muscle layers further comprises one or more perimeter artificial muscles; and

the one or more perimeter artificial muscles comprise fewer tab portions then the other artificial muscles of the at least of the plurality of artificial muscle layers.

6. The artificial muscle stack of claim 1 , wherein each of the plurality of artificial muscle layers comprises a plurality of artificial muscles.

7. The artificial muscle stack of claim 1 , wherein the first electrode and the second electrode each includes two pairs of tab portions and two pairs of bridge portions, each bridge portion interconnecting adjacent a pair of adjacent tab portions, each tab portion diametrically opposing an opposite tab portion.

8. The artificial muscle stack of claim 1 , wherein the first electrode is fixed to a first surface of the housing and the second electrode is fixed to a second surface of the housing.

9. The artificial muscle stack of claim 1 , wherein the electrode pair is actuatable between a non-actuated state and an actuated state such that actuation from the non-actuated state to the actuated state directs the dielectric fluid into the expandable fluid region, expanding the expandable fluid region.

10. The artificial muscle stack of claim 9 , wherein:

when the electrode pair is in the non-actuated state, the first electrode and the second electrode are non-parallel to one another; and

when the electrode pair is in the actuated state, the first electrode and the second electrode are parallel to one another, such that the first electrode and the second electrode are configured to zipper toward one another and toward the central opening when actuated from the non-actuated state to the actuated state.

11. The artificial muscle stack of claim 1 , further comprising a first electrical insulator layer fixed to an inner surface of the first electrode opposite a first surface of the housing and a second electrical insulator layer fixed to an inner surface of the second electrode opposite a second surface of the housing, wherein the first electrical insulator layer and the second electrical insulator layer each includes an adhesive surface and an opposite non-sealable surface.

12. An artificial muscle stack comprising:

three or more artificial muscle layers, wherein each artificial muscle layer comprises one or more artificial muscles, the one or more artificial muscles comprising:

a housing comprising an electrode region and an expandable fluid region;

a dielectric fluid housed within the housing; and

an electrode pair comprising a first electrode and a second electrode positioned in the electrode region of the housing, wherein:

the first electrode and the second electrode each comprise two or more tab portions and two or more bridge portions;

each of the two or more bridge portions interconnects adjacent tab portions; and

at least one of the first electrode and the second electrode comprises a central opening positioned between the two or more tab portions and encircling the expandable fluid region; and

wherein:

each inner artificial muscle layer is offset a first adjacent artificial muscle layer along a first tab axis and offset a second adjacent artificial muscle layer along a second tab axis; and

each tab axis extends from a center axis of the expandable fluid region to an end of at least one of the two or more tab portions of the one or more artificial muscles of the inner artificial muscle layer.

13. The artificial muscle stack of claim 12 , wherein the first tab axis is orthogonal the second tab axis.

14. The artificial muscle stack of claim 12 , wherein the electrode pair is actuatable between a non-actuated state and an actuated state such that actuation from the non-actuated state to the actuated state directs the dielectric fluid into the expandable fluid region, expanding the expandable fluid region.

15. The artificial muscle stack of claim 12 , wherein the first electrode is fixed to a first surface of the housing and the second electrode is fixed to a second surface of the housing.

16. The artificial muscle stack of claim 12 , wherein each of the three or more artificial muscle layers comprises a plurality of artificial muscles.

17. A method for actuating an artificial muscle stack, the method comprising:

generating a voltage using a power supply electrically coupled to an electrode pair of each artificial muscle of a plurality of artificial muscle layers, wherein:

each artificial muscle comprises a housing having an electrode region and an expandable fluid region;

a dielectric fluid is housed within the housing; and

the electrode pair comprises a first electrode and a second electrode and is positioned in the electrode region of the housing, wherein:

the first electrode and the second electrode each comprise two or more tab portions and two or more bridge portions;

each of the two or more bridge portions interconnects adjacent tab portions; and

at least one of the first electrode and the second electrode comprises a central opening positioned between the two or more tab portions and encircling the expandable fluid region, wherein the plurality of artificial muscle layers are arranged such that the expandable fluid region of each artificial muscle of each artificial muscle layer overlaps at least one tab portion of one or more artificial muscles of an adjacent artificial muscle layer; and

applying the voltage to the electrode pair of at least one artificial muscle of at least one of the plurality of artificial muscle layers, thereby actuating the electrode pair of the at least one artificial muscle from a non-actuated state to an actuated state such that dielectric fluid is directed into the expandable fluid region of the housing and expands the expandable fluid region.

18. The method of claim 17 , wherein adjacent artificial muscle layers are offset from one another along one or more tab axes, each tab axis extending from a center axis of the expandable fluid region of an individual artificial muscle of the plurality of artificial muscle layers to an end of at least one of the two or more tab portions of the individual artificial muscle of the plurality of artificial muscle layers.

19. The method of claim 18 , wherein the plurality of artificial muscle layers comprise at least three artificial muscle layers and each inner artificial muscle layer is offset a first adjacent artificial muscle layer along a first tab axis and offset a second adjacent artificial muscle layer along a second tab axis.

20. The method of claim 17 , the method further comprising applying the voltage to the electrode pair of each artificial muscle of each of the plurality of artificial muscle layers, thereby actuating the electrode pair of each artificial muscle from the non-actuated state to the actuated state such that dielectric fluid is directed into the expandable fluid region of the housing of each artificial muscle, expanding the expandable fluid region of each artificial muscle.