High power-to-mass ratio actuator
AssigneeMassachusetts Institute of Technology
InventorsIan W. Hunter, John D. Madden
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Abstract
A method for driving an actuator. The method includes applying an electrical potential across an electrostrictive material relative to a counterelectrode disposed within an electrolyte, thereby creating a double layer potential across a region of enhanced ionic concentration. A current flowing between the electorostrictive material and the counterelectrode is measured. A portion of the applied potential appearing across the electrolyte and counterelectrode is calculated and subtracted from the applied potential to obtain an estimated double layer potential. The applied electrical potential is adjusted to obtain a specified double layer potential.
Claims20
A method for driving an actuator where the actuator is characterized by a strain state, the method comprising:
- a. applying an electrical potential across an electrostrictive material relative to a counterelectrode disposed within an electrolyte, thereby creating a double layer potential across a boundary region of enhanced ionic concentration;
- b. measuring a current flowing between the electrostrictive material and the counterelectrode;
- c. calculating a portion of the applied potential appearing across the electrolyte;
- d. subtracting the portion of the applied potential appearing across the electrolyte from the applied potential to obtain an estimated double layer potential;
- and
- e. adjusting the applied electrical potential to obtain a specified double layer potential.
A method for driving an actuator, the actuator including an electrostrictive material disposed adjacent an electrolyte, the electrostrictive material characterized by a limiting double layer potential, the method comprising:
- a. applying an electrical potential, which is greater than the limiting double layer potential, across the electrostrictive material and electrolyte relative to a counterelectrode, resulting in a double layer potential and a current flowing between the electrostrictive material and the counterelectrode;
- and
- b. varying the electrical potential based at least on preventing the double layer potential from exceeding the limiting double layer potential.
Dependencies are inferred from the claim text.