Electrochemical actuator

• US 8,378,552 B2
• Filed: 12/12/2011
• Issued: 02/19/2013
• Est. Priority Date: 06/14/2004
• Status: Active Grant

• Current Assignee: Massachusetts Institute of Technology
• Original Assignee: Massachusetts Institute of Technology
• Inventors: Chiang, Yet-Ming, Cima, Michael J., Chin, Timothy E.
• Primary Examiner(s): Budd, Mark
• Application Number:
  US13/316,833
• Publication Number:
  US 20120146453A1
• Time in Patent Office: 435 Days
• Field of Search: 310/311, 310/328, 310/332, 310/364
• US Class Current: 310/311
• CPC Class Codes: F03G 7/005 Electro-chemical actuators; Actuators having a material for absorbing or desorbing gas, e.g. a metal hydride; Actuators using the difference in osmotic pressure between fluids; Actuators with elements stretchable when contacted with liquid rich in ions, with UV light, with a salt solution
• CPC Class Codes: H01M 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 2010/4292 Aspects relating to capacity ratio of electrodes/electrolyte or anode/cathode
• CPC Class Codes: H01M 4/485 of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy H01M4/505, H01M4/525 take precedence
• CPC Class Codes: H01M 4/505 of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
• CPC Class Codes: H01M 4/525 of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: H01M 50/409 Separators, membranes or diaphragms characterised by the material
• CPC Class Codes: H01M 6/30 Deferred-action cells
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The present invention provides systems, devices, and related methods, involving electrochemical actuation. In some cases, application of a voltage or current to a system or device of the invention may generate a volumetric or dimensional change, which may produce mechanical work. For example, at least a portion of the system may be constructed and arranged to be displaced from a first orientation to a second orientation. Systems such as these may be useful in various applications, including pumps (e.g., infusion pumps) and drug delivery devices, for example.

Claims

1. An actuator device, comprising:

an electrochemical cell including a negative electrode and a positive electrode, wherein at least a portion of the negative electrode is formed with a material formulated to at least one of intercalate, de-intercalate, alloy with, oxidize, reduce, or plate with the positive electrode such that a differential strain is imparted to the positive electrode, such that the differential strain produces a displacement of at least a portion of the electrochemical cell upon charging or discharging of the electrochemical cell.

2. The actuator device of claim 1, wherein the differential strain is imparted between a first portion of the positive electrode and a second portion of the positive electrode.

3. The actuator device of claim 1, wherein the material is formulated to at least one of intercalate, de-intercalate, alloy with, oxidize, reduce, or plate with a first portion of the positive electrode to an extent different than a second portion of the positive electrode such that the differential strain is imparted between the first portion and the second portion of the positive electrode.

4. The actuator device of claim 2, wherein the material includes an intercalating species.

5. The actuator device of claim 4, wherein the species is formulated to intercalate into the first portion to a different extent than the second portion.

6. The actuator device of claim 1, further comprising:

a structure configured to be displaced from a first orientation to a second orientation by displacement of the electrochemical cell.

7. The actuator device of claim 1, wherein discharging of the electrochemical cell causes the electrochemical cell to apply a force on a reservoir, thereby causing a fluid to be delivered from the reservoir.

8. A device for delivering a fluid to a patient comprising:

an electrochemical cell including a negative electrode and a positive electrode, wherein at least a portion of the negative electrode is formed with a material formulated to at least one of intercalate, de-intercalate, alloy with, oxidize, reduce, or plate with the positive electrode upon at least one of a charge or a discharge of the electrochemical cell, resulting in a deflection of at least one of the negative electrode or the positive electrode, and

wherein the deflection causes delivery of a fluid into a body.

9. The actuator device of claim 8, wherein the negative electrode and the positive electrode are mechanically coupled such that the deflection of the at least one of the negative electrode or the positive electrode produces a displacement of at least a portion of the electrochemical cell upon the at least one of charging or discharging of the electrochemical cell.

10. The actuator device of claim 8, wherein the at least a portion of the negative electrode is formed with a material formulated to at least one of intercalate, de-intercalate, alloy with, oxidize, reduce, or plate with the positive electrode such that a differential strain is imparted to the positive electrode.

11. The actuator device of claim 10, wherein the negative electrode and the positive electrode are mechanically coupled such that the differential strain produces the deflection of the at least one of the negative electrode and the positive electrode upon at least one of charging or discharging of the electrochemical cell.

12. The actuator device of claim 10, wherein the differential strain is imparted between a first portion of the positive electrode and a second portion of the positive electrode.

13. The actuator of claim 8, wherein the deflection is at least 25 percent of the initial volume.

14. The actuator device of claim 9, further comprising:

a structure configured to be displaced from a first orientation to a second orientation by the displacement of the electrochemical cell.

15. The device of claim 8, further comprising:

an electrical circuit electrically coupled to the negative electrode and the positive electrode so as to allow the electrochemical cell to discharge therethrough.

21. The device of claim 8, wherein the fluid includes a drug.

16. A device for delivering a therapeutic to a patient comprising:

a fluid reservoir;

a housing suited for removably associating the fluid reservoir with the body of the patient; and

an electrochemical cell including a negative electrode and a positive electrode, wherein at least a portion of the negative electrode is formed with a material formulated to at least one of intercalate, de-intercalate, alloy with, oxidize, reduce, or plate with the positive electrode such that a differential strain is imparted to the positive electrode, the differential strain producing a displacement of at least a portion of the electrochemical cell upon charging or discharging of the electrochemical cell,

wherein the displacement of at least a portion of the electromechanical cell is operative to cause fluid to be delivered from the fluid reservoir.

17. The device of claim 16, further comprising:

an electrical circuit electrically coupled to the negative electrode and the positive electrode so as to allow the electrochemical cell to discharge therethrough.

18. The device of claim 17, wherein the electrical circuit includes only fixed resistive elements.

19. The device of claim 16, further comprising:

a structure coupled to the housing and configured to be displaced from a first orientation to a second orientation by the displacement of the electrochemical cell.

20. The device of claim 16, wherein at least one of the positive electrode and the negative electrode is a bimorph electrode, the bimorph electrode including a dimensionally active material disposed on a non-dimensionally active material, the bimorph electrode configured to change volume or position upon charging or discharging of the electrochemical cell.

22. The device of claim 16, wherein the fluid delivered from the fluid reservoir includes a drug.