TRANSPORTATION OF MICROMETER-SIZED OBJECT AND EXTRACTION OF MECHANICAL WORK BY CONSTANT ELECTRIC FIELD

• US 20120001517A1
• Filed: 02/19/2010
• Published: 01/05/2012
• Est. Priority Date: 02/20/2009
• Status: Active Grant

• Current Assignee: Japan Science And Technology Agency
• Original Assignee: Japan Science And Technology Agency
• Inventors: Yoshikawa, Kenichi, Takinoue, Masahiro, Atsumi, Yu
• Granted Patent: US 9,126,198 B2
• Time in Patent Office: Days
• US Class Current: 310/309
• CPC Class Codes: B01L 2300/0861 Configuration of multiple channels and/or chambers in a single devices
• CPC Class Codes: B01L 2300/088 Channel loops
• CPC Class Codes: B01L 2300/089 Virtual walls for guiding liquids
• CPC Class Codes: B01L 2400/0415 electrical forces, e.g. electrokinetic
• CPC Class Codes: B01L 2400/0424 Dielectrophoretic forces
• CPC Class Codes: B01L 3/50273 characterised by the means or forces applied to move the fluids micropumps F04B19/006, of the membrane type F04B43/043
• CPC Class Codes: B01L 3/502792 for moving individual droplets on a plate, e.g. by locally altering surface tension
• CPC Class Codes: H02N 1/002 Electrostatic motors
• CPC Class Codes: H02N 1/004 in which a body is moved along a path due to interaction with an electric field travelling along the path
• CPC Class Codes: H02N 1/10 with non-conductive charge carrier

Abstract

A technique capable of making an object move and transporting it without generation of a current, and extracting mechanical work. As a result of diligent effort, the present inventors have found that by arranging two electrodes for generating an electric field for a dielectric body of a micrometer-size or the like in an insulating fluid such as oil, such that the central axes of the two electrodes are not aligned, and applying an electric field (for example, constant electric field), the dielectric body can be transported three-dimensionally at will, and as a result, mechanical work can be extracted.

Claims

1. A method of transporting a dielectric body, comprising:

arranging two electrodes for generating an electric field so that the central axes of the two electrodes are not aligned; and

applying an electric field to the dielectric body in an insulating fluid causing movement of the dielectric body.

2. The method according to claim 1, wherein said dielectric body is of a micrometer-size, and the micrometer-size ranges from several nm to 1000 μ

m.

3. The method according to claim 2, wherein said micrometer-size ranges from 1 μ

m to 100 μ

m.

4. The method according to claim 1, wherein said dielectric body is a substance generating dielectric polarization but not generating a current when an electrostatic field is applied, and is a substance having electrostatic chargeability.

5. The method according to claim 1, wherein said dielectric body is selected from the group consisting of a water droplet, a polymeric substance and a glass bead.

6. The method according to claim 5, wherein said water droplet is generated by using a surfactant.

7. The method according to claim 5, wherein said surfactant is generated by using dioleoyl phosphatidylcholine (DOPC), dioleoyl phosphatidylethanolamine (DOPE), dioleoyl phosphatidylserine (DOPS), eggPC, stearyl trimethyl ammonium chloride (STAC), stearyl trimethyl ammonium bromide (STAB), sodium dodecyl sulfate (SDS), dodecyl trimethyl ammonium chloride and pentaethylene glycol dodecyl ether.

8. The method according to claim 1, wherein said insulating fluid is a substance that is non-volatile, non-conductive, and fluent under normal temperature and normal pressure, and has a specific gravity with respect to said micrometer-sized dielectric body of within ±

50%.

9. The method according to claim 1, wherein said insulating fluid is selected from the group consisting of mineral oil, liquid paraffin, alkane and silicone oil.

10. The method according to claim 1, wherein said electric field is a constant electric field.

11. The method according to claim 1, wherein said electric field is subject to the range from 1 V to 1000 V.

12. The method according to claim 1, wherein a positive electrode and a negative electrode for generating said electric field are arranged so that their central axes are not parallel with each other.

13. The method according to claim 12, wherein said electrode has a pyramid or conical shape having a sharp tip, or a prismatic or cylindrical shape, and has a material having conductivity.

14. The method according to claim 12, wherein said electrode is a conductive substance selected from the group consisting of tungsten, tungsten carbide, gold, platinum, silver, copper, iron and aluminum.

15. The method according to claim 1, wherein said electric field is generated by a set of at least two electrodes of a positive electrode and a negative electrode, and an orientation of the set of at least two electrodes is such that at least two are in different directions each other, the method further comprising the step of changing a route or mode of motion by controlling said electric field and a spatial arrangement of electrodes for generating said electric field.

16. The method according to claim 15, wherein said control is realized by shifting an electrode to a desired position by manipulating each coordinate using a micromanipulator capable of manipulating each of three-dimensional coordinates by 1 μ

m, or by manipulation with a hand or tweezers.

17. The method according to claim 1, further comprising the step of transporting said dielectric body by indirectly controlling the dielectric body by spatial control of said electrodes and control of intensity of an applied voltage.

18. The method according to claim 1, wherein a micro-turbine is arranged in a space where said dielectric body is movable, and work is extracted from the micro-turbine that moves by motion of the dielectric body, and the micro-turbine has a rotation axis and a part of a blade, the blade being rotatable about the rotation axis.

19. The method according to claim 1, wherein there are a plurality of said dielectric bodies, and the plurality of dielectric bodies are caused to collectively move to function as a motor.

20. The method according to claim 1, which is used in mechanical control of a polymer, liquid droplet transportation of a pharmaceutical or chemical, a chemical reaction, pharmaceutical or chemical preparation, non-contact transportation of a biological sample, or a micro-channel.

21. An apparatus of transporting a dielectric body comprising:

an insulating fluid for receiving the dielectric body; and

a means for applying an electric field including two electrodes, residing in the insulating fluid, the two electrodes being arranged so that their central axes are not aligned.

23. The apparatus according to claim 21, wherein said dielectric body is of a micrometer-size, and the micrometer-size ranges from several nm to 1000 μ

m.

24. The apparatus according to claim 23, wherein said micrometer-size ranges from 1 μ

m to 100 μ

m.

25. The apparatus according to claim 21, wherein said dielectric body is a substance generating dielectric polarization but not generating a current when an electrostatic field is applied, and is a substance having electrostatic chargeability.

26. The apparatus according to claim 21, wherein said dielectric body is selected from the group consisting of a water droplet, a polymeric substance and a glass bead.

27. The apparatus according to claim 26, wherein said water droplet is generated by using a surfactant.

28. The apparatus according to claim 26, wherein said surfactant is generated by using at least one substance selected from the group consisting of dioleoyl phosphatidylcholine (DOPC), dioleoyl phosphatidylethanolamine (DOPE), dioleoyl phosphatidylserine (DOPS), eggPC, stearyl trimethyl ammonium chloride (STAC), stearyl trimethyl ammonium bromide (STAB), sodium dodecyl sulfate (SDS), dodecyl trimethyl ammonium chloride and pentaethylene glycol dodecyl ether.

29. The apparatus according to claim 21, wherein said insulating fluid is a substance that is non-volatile, non-conductive, and fluent under normal temperature and normal pressure, and has a specific gravity with respect to said micrometer-sized dielectric body of within ±

50%.

30. The apparatus according to claim 21, wherein said insulating fluid is selected from the group consisting of mineral oil, liquid paraffin, alkane and silicone oil.

31. The apparatus according to claim 21, wherein said electric field is a constant electric field.

32. The apparatus according to claim 21, wherein said electric field is subject to the range from 1 V to 1000 V.

33. The apparatus according to claim 21, wherein a positive electrode and a negative electrode for generating said electric field are arranged so that their central axes are not parallel with each other.

34. The apparatus according to claim 33, wherein said electrode has a pyramid or conical shape having a sharp tip, or a prismatic or cylindrical shape, and has a material having conductivity.

35. The apparatus according to claim 32, wherein said electrode is a conductive substance selected from the group consisting of tungsten, tungsten carbide, gold, platinum, silver, copper, iron and aluminum.

36. The apparatus according to claim 21, wherein said means for applying an electric field is a set of at least two electrodes of a positive electrode and a negative electrode, and the orientation of the set of at least two electrodes is such that at least two are in different directions each other.

37. The apparatus according to claim 36, further comprising a micromanipulator capable of manipulating each of three-dimensional coordinates by 1 μ

m, the micromanipulator manipulating each coordinate to shift an electrode to a desired position, or further comprising tweezers.

38. The apparatus according to claim 21, further comprising a means for transporting said dielectric body by indirectly controlling the dielectric body by spatial control of said electrodes and control of intensity of an applied voltage.

41. The apparatus according to claim 21 for use in mechanical control of a polymer, liquid droplet transportation of a pharmaceutical or chemical, a chemical reaction, pharmaceutical or chemical preparation, non-contact transportation of a biological sample, or a micro-channel.

22. An apparatus for extracting mechanical work, comprising:

an insulating fluid;

a dielectric body arranged in the insulating fluid;

a means for applying an electric field including two electrodes, residing in the insulating fluid, the two electrodes being arranged so that their central axes are not aligned; and

a means for extracting mechanical work from the dielectric body.

39. The apparatus according to claim 22, further comprising a micro-turbine.

40. The apparatus according to claim 22, wherein there are a plurality of said dielectric bodies, and the plurality of dielectric bodies are caused to collectively move to function as a motor.