Hydraulic muscle from hollow wrapped carbon nanotube yarn
A hydraulic muscle comprises a hollow carbon nanotube (CNT) yarn tube comprising: a plurality of CNT sheets twisted and wrapped in form of a hollow tube; and a binding agent infiltrated in the plurality of CNT sheets that binds the plurality of the CNT sheets together. A method of manufacturing a hydraulic muscle comprises: twisting and wrapping a plurality of carbon nanotube (CNT) sheets around a core fiber; infiltrating a binding agent in between the plurality of CNT sheets, wherein the binding agent binds the plurality of the CNT sheets together; and removing the core fiber from the plurality of CNT sheets.
1. A hydraulic muscle comprising:
a hollow carbon nanotube (CNT) actuation tube comprising:
a plurality of CNT sheets wrapped in form of a hollow tube; and
a binding agent infiltrated in the plurality of CNT sheets that binds the plurality of the CNT sheets together and seals the hollow CNT actuation tube from leaking, wherein
the hollow CNT actuation tube has an inner diameter, a central axis, and a length;
a wrapping direction of the plurality of CNT sheets and the central axis forms a bias angle at a first value larger than 0 degree and smaller than 90 degrees; and
an increase of an internal pressure of the hollow CNT actuation tube causes an increase in the inner diameter, a decrease in the length, and a change of the bias angle from the first value to a second value.
2. The hydraulic muscle according to claim 1 , further comprising a spring, wherein
the plurality of CNT sheets are wrapped around outside surfaces of the spring.
3. The hydraulic muscle according to claim 1 , wherein
two opposite ends of the hollow CNT actuation tube are prevented from rotating so that
when the internal pressure inside the hollow CNT actuation tube is applied, the hollow CNT actuation tube creates a torque inside the hollow CNT actuation tube such that the hydraulic muscle snarls along the length of the hollow CNT actuation tube.
4. The hydraulic muscle according to claim 1 , wherein
the hollow CNT actuation tube has a shape of a coil,
two opposite ends of the hollow CNT actuation tube are prevented from rotating,
the hydraulic muscle further comprises a supporting material disposed on the hydraulic muscle, preventing the hydraulic muscle from uncoiling, and
when the internal pressure inside the hollow CNT actuation tube is applied, the hollow CNT actuation tube creates a torque inside the hollow CNT actuation tube that changes a length of the hydraulic muscle linearly along a central axis of the coil of the hydraulic muscle.
5. The hydraulic muscle according to claim 4 , further comprising a spring, wherein the plurality of CNT sheets are wrapped around the spring.
6. The hydraulic muscle according to claim 4 , wherein the supporting material is a silicone layer.
7. The hydraulic muscle according to claim 4 , wherein
the hydraulic muscle is homochiral, and
the torque inside the hollow CNT actuation tube contracts the hydraulic muscle linearly along the central axis of the coil of the hydraulic muscle.
8. The hydraulic muscle according to claim 4 , wherein
the hydraulic muscle is heterochiral, and
when the torque inside the hollow CNT actuation tube extends the hydraulic muscle linearly along the central axis of the coil of the hydraulic muscle.
9. The hydraulic muscle according to claim 1 , wherein
two opposite ends of the hollow CNT actuation tube are prevented from linear actuation, and
when the internal pressure inside the hollow CNT actuation tube is applied, the hollow CNT actuation tube creates a torque inside the hollow CNT actuation tube that twists the CNT yarn tube along a direction of twisting the plurality of CNT sheets.
10. The hydraulic muscle according to claim 1 , wherein
a gas or liquid inside the hollow CNT actuation tube is heated via an electrical current passing the plurality of CNT sheets, and
a thermal expansion of the gas or liquid actuates the hollow CNT actuation tube.
11. A method of manufacturing a hydraulic muscle, the method comprising:
wrapping a plurality of carbon nanotube (CNT) sheets around a core fiber with a bias angle at a first value greater than 0 degree and smaller than 90 degrees in form of a hollow CNT tube;
infiltrating a binding agent in between the plurality of CNT sheets, wherein
the binding agent binds the plurality of the CNT sheets together and seals the plurality of CNT sheets from leaking; and
removing the core fiber from the plurality of CNT sheets, wherein
an increase of an internal pressure of the hollow CNT tube causes an increase in a diameter of the hollow CNT tube, a decrease in a length of the hollow CNT tube, and a change of the bias angle of the hollow CNT tube from the first value to a second value.
12. The method according to claim 11 , further comprising:
coiling the core fiber along with the plurality of CNT sheets and the binding agent; and
applying a silicone layer on the plurality of CNT sheets as a support before removing the core fiber.
13. The method according to claim 11 , further comprising:
disposing a catalyst on the core fiber before wrapping the plurality of CNT sheets around the core fiber, wherein
the catalyst adheres to interior walls of the wrapped plurality of CNT sheets;
the catalyst stays on the interior walls of the wrapped plurality of CNT sheets when the core fiber is removed, and
the catalyst initiates a chemical reaction of a chemical/fuel inside the CNT yarn tube.
14. The method according to claim 13 , wherein the chemical/fuel is a hydrazine and the catalyst is silver.
15. The method according to claim 13 , wherein the chemical/fuel is hydrogen peroxide (H 2 O 2 ) and the catalyst is magnesium dioxide.