Multi-segment reinforced actuators and applications
A multi-segment reinforced actuator includes (a) a soft actuator body that defines a chamber and (b) a plurality of distinct reinforcement structures on or in respective segments of the soft actuator body. First and second reinforcement structures are respectively configured to produce a first and second actuation motions, respectively, in first and second segments of the soft actuator or body when fluid flows into or out of the chamber. The actuation motions are selected bending, extending, expansion, contraction, twisting, and combinations thereof; and the first actuation motion differs from the second actuation motion. The actuator can be used, e.g., to facilitate bending of the thumb with corresponding bending, extending, expansion, contraction, and twisting actuation motions.
1. A method for variable actuation along multiple segments of an actuator, the method comprising:
attaching a soft actuator body to a digit of a human hand, wherein the digit includes a plurality of joints, and wherein the soft actuator body defines a chamber and includes a plurality of distinct reinforcement structures on or in respective segments of the soft actuator body; and
pumping fluid into or out of the chamber to produce an actuation motion in each segment of the soft actuator body selected from at least one of the following types: bending, extending, expansion, contraction, twisting and combinations thereof, wherein the respective reinforcement structures in the segments cause a first segment to actuate with a motion of a first type and cause a second segment to actuate with a motion of a second type, wherein the first type is a different type than the second type, and wherein the respective actuation motions in the respective segments cause or mechanically assist the digit to bend or straighten at the joints.
2. The method of claim 1 , wherein the actuator includes five segments, and wherein the pumping of the fluid into or out of the chamber causes the first segment to actuate with a twisting and bending motion, causes the second segment to actuate with a twisting and extending motion, causes a third segment to actuate with a bending motion, causes a fourth segment to actuate with an extending motion, and causes a fifth segment to actuate with a bending motion.
3. The method of claim 2 , wherein the digit to which the actuator is attached is a human thumb having two joints.
4. The method of claim 1 , wherein the actuator includes seven segments, and wherein the pumping of the fluid into or out of the chamber causes the first segment to actuate with a bending motion, causes the second segment to actuate with an extending motion, causes the third segment to actuate with a bending motion, causes the fourth segment to actuate with an extending motion, causes the fifth segment to actuate with a bending motion, causes the sixth segment to actuate with an extending motion, and causes the seventh segment to actuate with a bending motion.
5. The method of claim 1 , wherein at least one of the reinforcement structures is in the form of at least one fiber wound clockwise or counterclockwise about and along the soft actuator body.
6. The method of claim 5 , wherein the actuator includes a plurality of fibers, and wherein at least a first fiber is wound counterclockwise about and along the soft actuator body, and wherein at least a second fiber is wound clockwise about and along the soft actuator body, wherein the second fiber crosses the first fiber with each winding.
7. The method of claim 1 , wherein at least one of the reinforcement structures is in the form of a perforated sheet defining apertures extending longitudinally on or through the soft actuator body.
8. The method of claim 1 , wherein the aforementioned chamber is herein referenced as a first chamber, and wherein the actuator further comprises a second chamber, the method further comprising pumping fluid into the second chamber to produce a second actuation motion or functionality distinct from the actuation motion produced by pumping fluid into the first chamber.
9. The method of claim 8 , wherein the second actuation motion or functionality includes an actuation selected from stiffening and bending in a direction different from the bending of the first chamber.
10. The method of claim 1 , wherein the actuator includes at least five segments, and wherein every other segment in sequence along the actuator actuate with a motion that includes bending, wherein segments between the segments that actuate with the bending motion actuate with a different actuation motion.
11. A method for variable actuation along multiple segments of an actuator, the method comprising:
using a soft actuator body that defines a chamber and that includes a plurality of distinct reinforcement structures on or in respective segments of the soft actuator body;
pumping fluid into or out of the chamber to produce an actuation motion in each segment of the soft actuator body selected from at least one of the following types: bending, extending, expansion, contraction, twisting and combinations thereof, wherein the respective reinforcement structures in the segments cause a first segment to actuate with a motion of a first type and cause a second segment to actuate with a motion of a second type, wherein the first type is a different type than the second type; and
grasping or displacing an internal body part or soft tissue with the actuator via the actuations during surgery.
12. The method of claim 11 , further comprising inserting the actuator through a trocar into a human, wherein the internal body part is then grasped or displaced by pumping fluid into the chamber.
13. The method of claim 11 , wherein at least one of the reinforcement structures is in the form of at least one fiber wound clockwise or counterclockwise about and along the soft actuator body.
14. The method of claim 13 , wherein the actuator includes a plurality of fibers, and wherein at least a first fiber is wound counterclockwise about and along the soft actuator body, and wherein at least a second fiber is wound clockwise about and along the soft actuator body, wherein the second fiber crosses the first fiber with each winding.
15. The method of claim 11 , wherein at least one of the reinforcement structures is in the form of a perforated sheet defining apertures extending longitudinally on or through the soft actuator body.
16. The method of claim 11 , wherein the aforementioned chamber is herein referenced as a first chamber, and wherein the actuator further comprises a second chamber, the method further comprising pumping fluid into the second chamber to produce a second actuation motion or functionality distinct from the actuation motion produced by pumping fluid into the first chamber.
17. The method of claim 16 , wherein the second actuation motion or functionality includes an actuation selected from stiffening and bending in a direction different from the bending of the first chamber.