System and methods for actuation using electro-osmosis
AssigneeCornell University
InventorsRobert MacCurdy, Hod Lipson
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Abstract
The invention exploits a widely used device in micro-fluidics, the electro-osmotic pump (EOP), to create very low energy micro-scale and macro-scale mechanical actuators. The EOP uses electrical fields to move naturally occurring charged particles (ions) through a fluid medium. As the ions move in response to the applied field, they drag the (non-charged) fluid along, establishing bulk flow. When confined to a narrow chamber, a pressure gradient can be established. The combination of pressure gradient and flow performs mechanical work. With the use of electro-osmotic pumps, the invention enables actuators to be constructed in a variety of embodiments, including for example, a sheet structure, a piston structure, and a cellular structure to name a few.
Claims12
A mechanical actuator, comprising
- a first flexible sheet including a first top side and a first bottom side, each side coated with a first conductive layer, the first flexible sheet comprising a plurality of first chambers;
- a second flexible sheet including a second top side and a second bottom side, each side coated with a second conductive layer, the second flexible sheet comprising a plurality of second chambers;
- a third flexible sheet including a third top side and a third bottom side, wherein the third flexible sheet comprises a plurality of third chambers of a honey-comb arrangement;
- the second top side of the second flexible sheet is fused to the third bottom side of the third flexible sheet at a plurality of regular intervals and the first bottom side of the first flexible sheet is fused to the third top side of the third flexible sheet at a plurality of regular intervals to obtain an assembled flexible sheet structure including a plurality of assembled chambers;
- an outer membrane including a working fluid, wherein the assembled flexible sheet structure is positioned inside the outer membrane to create the mechanical actuator;
- and
- the assembled flexible sheet structure configured to contract and expand to form a linear actuator when a voltage is applied to pump the working fluid across the assembled flexible sheet structure and into the plurality of assembled chambers.
A mechanical actuator, comprising:
- a piston including a cylinder and a head with a plurality of perforations;
- an enclosed chamber filled with a working fluid, wherein the enclosed chamber includes an aperture through which the piston is positioned within the enclosed chamber;
- one or more electrodes on the piston, wherein the one or more electrodes are configured to be charged to create an electric field in order to move the working fluid and actuate the piston.
A mechanical actuator, comprising
- a first flexible sheet including a first top side and a first bottom side, each side coated with a first conductive layer, the first flexible sheet comprising a plurality of first chambers;
- a second flexible sheet including a second top side and a second bottom side, each side coated with a second conductive layer, the second flexible sheet comprising a plurality of second chambers;
- the second top side of the second flexible sheet is fused to the first bottom side of the first flexible sheet at a plurality of regular intervals to obtain an assembled flexible cellular structure including a plurality of assembled chambers;
- a working fluid positioned inside the flexible cellular structure to create the mechanical actuator, wherein the plurality of assembled chambers are separated by individually addressable permeable layers such that voltage applied to one or more individually addressable permeable layers causes the working fluid to flow from one chamber into an adjacent chamber such that select chambers of the plurality are configured to contract and expand.
Dependencies are inferred from the claim text.