High energy density electro-osmotic pump and actuator

A nastic actuator, comprising:

• an electro-osmotic pump, including a pump chamber having a wall, at least a portion of the wall being fabricated of an electric double layer material, the surface area of the electric double layer material being high relative to the volume of the pump chamber, such that an electric potential, when applied across the material in a first direction, causes a fluid in the pump chamber to be transported through the wall into the pump chamber, and when applied across the material in a second direction, causes the fluid to be transported through the wall out of the pump chamber;
• an actuator chamber, having a variable volume, coupled to the pump chamber;
• and
• a superabsorbent polymer disposed in the pump chamber and the actuator chamber,
• such that transport of the fluid into the pump chamber results in absorption of the fluid by the superabsorbent polymer, causing the actuator chamber to increase in volume,
• such that the electric potential, when applied across the superabsorbent polymer in the first direction, causes the superabsorbent polymer to expand, further causing the actuator chamber to increase in volume,
• such that transport of the fluid out of the pump chamber results in release of the fluid from the superabsorbent polymer, causing the actuator chamber to decrease in volume, and
• such that the electric potential, when applied across the superabsorbent polymer in the second direction, causes the superabsorbent polymer to contract, thereby further causing the actuator chamber to decrease in volume.

A nastic actuator, comprising:

• an electro-osmotic pump, including a first pump chamber, a second pump chamber, a fluid in the first and second pump chambers, and a wall common to the first and second pump chambers, at least a portion of the wall being fabricated of an electric double layer material, the surface area of the electric double layer material being high relative to the volume of the first pump chamber and relative to the volume of the second pump chamber, such that an electric potential, when applied across the material in a first direction, causes the fluid to be transported through the wall from the second pump chamber to the first pump chamber, and when applied across the material in a second direction, causes the fluid to be transported through the wall from the first pump chamber to the second pump chamber;
• a first actuator chamber, having a first variable volume, coupled to the first pump chamber;
• a second actuator chamber, having a second variable volume, coupled to the second pump chamber;
• a first superabsorbent polymer disposed in the first pump chamber and the first actuator chamber;
• a second superabsorbent polymer disposed in the second pump chamber and the second actuator chamber;
• such that transport of the fluid from the first pump chamber to the second pump chamber results in absorption of the fluid by the second superabsorbent polymer, causing the second actuator chamber to increase in volume, and results in release of the fluid by the first superabsorbent polymer, causing the first actuator chamber to decrease in volume,
• such that the electric potential, when applied across the first and second superabsorbent polymers in the second direction, causes the second superabsorbent polymer to expand, further causing the second actuator chamber to increase in volume, and causes the first superabsorbent polymer to contract, further causing the first actuator chamber to decrease in volume,
• such that transport of the fluid from the second pump chamber to the first pump chamber results in absorption of the fluid by the first superabsorbent polymer, causing the first actuator chamber to increase in volume, and results in release of the fluid by the second superabsorbent polymer, causing the second actuator chamber to decrease in volume, and
• such that the electric potential, when applied across the first and second superabsorbent polymers in the first direction, causes the first superabsorbent polymer to expand, further causing the first actuator chamber to increase in volume, and causes the second superabsorbent polymer to contract, further causing the second actuator chamber to decrease in volume.

A structure with distributed shape control, comprising:

• a plurality of nastic actuators distributed in the structure, each actuator including:
• an electro-osmotic pump, including a pump chamber having a wall, at least a portion of the wall being fabricated of an electric double layer material, the surface area of the electric double layer material being high relative to the volume of the pump chamber, such that an electric potential, when applied across the material in a first direction, causes a fluid in the pump chamber to be transported through the wall into the pump chamber, and when applied across the material in a second direction, causes the fluid to be transported through the wall out of the pump chamber;
• an actuator chamber, having a variable volume, coupled to the pump chamber;
• and
• a superabsorbent polymer disposed in the pump chamber and the actuator chamber,
• such that transport of the fluid into the pump chamber results in absorption of the fluid by the superabsorbent polymer, causing the actuator chamber to increase in volume,
• such that the electric potential, when applied across the superabsorbent polymer in the first direction, causes the superabsorbent polymer to expand, further causing the actuator chamber to increase in volume,
• such that transport of the fluid out of the pump chamber results in release of the fluid from the superabsorbent polymer, causing the actuator chamber to decrease in volume, and
• such that the electric potential, when applied across the superabsorbent polymer in the second direction, causes the superabsorbent polymer to contract, further causing the actuator chamber to decrease in volume.

A method of making a nastic actuator, comprising:

• providing an electro-osmotic pump, including a pump chamber having a wall, at least a portion of the wall being fabricated of an electric double layer material, the surface area of the electric double layer material being high relative to the volume of the pump chamber, such that an electric potential, when applied across the material in a first direction, causes a fluid in the pump chamber to be transported through the wall into the pump chamber, and when applied across the material in a second direction, causes the fluid to be transported through the wall out of the pump chamber;
• coupling an actuator chamber, having a variable volume, to the pump chamber;
• and
• disposing a superabsorbent polymer in the pump chamber and in the actuator chamber,
• such that transport of the fluid into the pump chamber results in absorption of the fluid by the superabsorbent polymer, causing the actuator chamber to increase in volume,
• such that the electric potential, when applied across the superabsorbent polymer in the first direction, causes the superabsorbent polymer to expand, further causing the actuator chamber to increase in volume,
• such that transport of the fluid out of the pump chamber results in release of the fluid from the superabsorbent polymer, causing the actuator chamber to decrease in volume, and
• such that the electric potential, when applied across the superabsorbent polymer in the second direction, causes the superabsorbent polymer to contract, thereby further causing the actuator chamber to decrease in volume.

A method of implementing distributed shape control in a structure, comprising:

• embedding a plurality of nastic actuators in the structure, including, for each actuator:
• providing an electro-osmotic pump, including a pump chamber having a wall, at least a portion of the wall being fabricated of an electric double layer material, the surface area of the electric double layer material being high relative to the volume of the pump chamber, such that an electric potential, when applied across the material in a first direction, causes a fluid in the pump chamber to be transported through the wall into the pump chamber, and when applied across the material in a second direction, causes the fluid to be transported through the wall out of the pump chamber;
• coupling an actuator chamber, having a variable volume, to the pump chamber;
• and
• disposing a superabsorbent polymer in the pump chamber and in the actuator chamber,
• such that transport of the fluid into the pump chamber results in absorption of the fluid by the superabsorbent polymer, causing the actuator chamber to increase in volume,
• such that the electric potential, when applied across the superabsorbent polymer in the first direction, causes the superabsorbent polymer to expand, further causing the actuator chamber to increase in volume,
• such that transport of the fluid out of the pump chamber results in release of the fluid from the superabsorbent polymer, causing the actuator chamber to decrease in volume, and
• such that the electric potential, when applied across the superabsorbent polymer in the second direction, causes the superabsorbent polymer to contract, further causing the actuator chamber to decrease in volume.