Linear electrowetting-based actuator
Disclosed is an electrowetting-based apparatus comprising, in some embodiments, a plurality of immiscible fluids. The boundary between the fluids is made substantially planar with the application of select voltages to electrodes distributed around the cell containing the fluids. The electrodes are also adapted to alter the orientation of the substantially-planar fluid boundary, thereby allowing the fluid boundary to be steered in a determined direction. Light impinging on the boundary may therefore be refracted and redirected in a determined direction. Similarly, a reflective surface may be held in suspension at the fluid boundary, thereby providing a mirror with which to redirect impinging light. The electrowetting cell disclosed herein may be used as an optical switch, actuator, lens, concentrator, or like device.
1. An electrowetting-based actuator comprising:
a suspension medium comprising a plurality of immiscible fluids; the fluids comprising an electrolyte and a second fluid;
a reflective sheet suspended by the electrolyte and the second fluid at a boundary between the electrolyte and the second fluid; and
at least one electrode capacitively coupled to the suspension medium;
wherein application of a determined voltage to one or more of the at least one electrode displaces the electrolyte to induce a displacement of the reflective sheet.
2. The actuator of claim 1 , wherein the electrolyte comprises a saline solution.
3. The actuator of claim 2 , wherein the saline solution comprises sodium.
4. The actuator of claim 1 , wherein the second fluid comprises an insulator.
5. The actuator of claim 1 , wherein the second fluid comprises hydrocarbon.
6. The actuator of claim 1 , wherein the hydrocarbon comprises one or more alkanes.
7. The actuator of claim 1 , wherein the surface is a reflector.
8. The actuator of claim 1 , wherein the reflective sheet is a mirror.
9. The actuator of claim 8 , wherein the mirror comprises aluminized Mylar.
10. The actuator of claim 1 , wherein the reflective sheet comprises a substantially planar sheet having a first side and a second side, wherein the first side is hydroscopic and the second side is hydrophobic.
11. The actuator of claim 10 , wherein the first side comprises a layer of acetate.
12. The actuator of claim 10 , wherein the second side comprises a layer of tetrafluoro ethylene (TFE).
13. The actuator of claim 1 , wherein the actuator further comprises a dielectric in proximity to one or more of the at least one electrode.