Transportation of micrometer-sized object and extraction of mechanical work by constant electric field

• US 9,126,198 B2
• Filed: 02/19/2010
• Issued: 09/08/2015
• Est. Priority Date: 02/20/2009
• Status: Active Grant

• Current Assignee: Japan Science & Technology Trading Co. Limited
• Original Assignee: Japan Science & Technology Trading Co. Limited
• Inventors: Yoshikawa, Kenichi, Takinoue, Masahiro, Atsumi, Yu
• Primary Examiner(s): Kim, John K
• Application Number:
  US13/202,320
• Publication Number:
  US 20120001517A1
• Time in Patent Office: 2,027 Days
• Field of Search: 310/300, 310/308, 310/309, 310/12.03, 310/11, 204/600, 204/547, 204/569, 204/643, 200/182
• US Class Current: 1/1
• 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. An apparatus for transporting a dielectric body comprising:

an insulating fluid for receiving the dielectric body, the insulating fluid being of different composition to the dielectric body;

two electrodes; and

a means for applying a constant voltage between the two electrodes to generate a constant electric field, the two electrodes residing in the insulating fluid, the two electrodes having central axes, the central axes running along the center of their respective electrodes and being parallel to the direction of the maximum length of their respective electrodes, the two electrodes being arranged so that their central axes are sufficiently not aligned such that when the constant electric field is applied to a dielectric body, two dimensional cyclic motion of the dielectric body is generated.

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

m.

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

m to 100 μ

m.

4. The apparatus 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 apparatus 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 apparatus according to claim 5, wherein said dielectric body is a water droplet, and wherein said water droplet is generated by using a surfactant.

7. The apparatus according to claim 6, 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.

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

11. The apparatus 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.

12. The apparatus according to claim 11, 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.

13. The apparatus according to claim 10, wherein said electrode is a conductive substance selected from the group consisting of tungsten, tungsten carbide, gold, platinum, silver, copper, iron and aluminum.

14. The apparatus according to claim 1, wherein the two electrodes comprise a positive electrode and a negative electrode, and the orientation of the two electrodes is such that the two electrodes are in different directions to each other.

15. The apparatus according to claim 14, 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.

16. The apparatus according to claim 1, further comprising a means for transporting said dielectric body by indirectly controlling the dielectric body by spatial control of said electrodes.

17. The apparatus according to claim 1 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.

18. An apparatus for extracting mechanical work, comprising:

an insulating fluid;

a dielectric body arranged in the insulating fluid, the dielectric body being of different composition to the insulating fluid;

two electrodes;

a means for applying a constant voltage between the two electrodes to generate a constant electric field, the two electrodes residing in the insulating fluid, the two electrodes having central axes, the central axes running along the center of their respective electrodes and being parallel to the direction of the maximum length of their respective electrodes, the two electrodes being arranged so that their central axes are sufficiently not aligned such that when the constant electric field is applied to a dielectric body, two dimensional cyclic motion of the dielectric body is generated; and

a means for extracting mechanical work from the dielectric body.

19. The apparatus according to claim 18, further comprising a micro-turbine.

20. The apparatus according to claim 18,

further comprising a plurality of dielectric bodies including said dielectric body, and the plurality of dielectric bodies are caused to collectively move to function as a motor.