Electro-adhesion device

ES 2 272 503 T3

DESCRIPTION

Electroadhesion device.

Field of the invention

This invention relates to an electroadhesion device.

Background of the invention

Electroadhesion is the process of creating a charge on an object and in this way attracting it to a special surface. Electroadhesion devices for attracting a non-magnetic object such as paper have not been introduced as consumer products due to the fact that they are not effective, that they do not create sufficient adhesion force, or they are very expensive to manufacture due to the complexity of these devices.

A further problem is that it is very difficult to create a bonding device that will attract objects of a variety of materials with sufficient force. It is this application of the invention that should be kept in mind predominantly but not exclusively.

United States Patent No. 4,384,918 teaches that different types of bipolar sleeves are suitable for electrically bonding conductive or non-conductive objects, and describes an electrostatic device for sleeve clamping a material having at least one conductive portion.

United States Patent No. 4,838,529 teaches a specific electrostatic clamp or sleeve configuration that allows a dielectric substrate to be fixed at lower voltages than conventional fixing voltages by reducing the space and width of the electrodes to less than 100 pm.

The known art does not characterize an electroadhesion device capable of attracting or fixing both conductive and dielectric materials using a particular electrode configuration as proposed in the present invention.

Summary of the invention

The invention is defined by the features of claim 1. Preferred embodiments of the invention are defined in the dependent claims.

The electrodes can be located on opposite sides of the base when the base is made of a substance that has a high dielectric constant (epsilon), typically at least 5. The electrodes of a pair of electrodes can be located on opposite sides of the base, providing energy to that pair of electrodes, during use, so that they are polarized in an opposite way, thus causing a charge differential in one part of the base. object adjacent to that pair of electrodes which in turn will cause the object to be attracted to the electroadhesion surface.

Each of the electrodes may have an outer surface that faces away from the base whose outer surface defines at least a part of the electroadhesion surface and whose outer surface has dimensions in any direction greater than the distance from said outer surface to the base, whose distance is the thickness of the electrode. The electrode is typically extremely thin so as to limit the accumulated charge between adjacent electrodes. Electrodes are typically less than 5 µm thick.

The electrodes can be screen printing electrodes. The electrodes can be vapor deposition electrodes.

The electroadhesion device may be configured so that there may be some air trapped between adjacent electrodes.

The electrodes can be elongated electrodes located substantially parallel to one another on one side of the base.

Adjacent electrodes may be located a minimum distance from each other which is related to a Maximum withstand voltage between the electrodes before the disruptive electrical discharge occurs. Since the electro-adhesion force is proportional to the voltage between a pair of electrodes, the minimum distance can be selected so that an appropriate voltage is achieved between a pair of electrodes in order to achieve a sufficient electro-adhesion force without the occurrence of bonding. disruptive electrical discharge. Adjacent electrodes may be located spaced apart from each other by a fixed or variable distance greater than or equal to the minimum distance.

The electrodes may be shaped to limit the sharpness of the electrode corners, thereby reducing the possibility of disruptive electrical discharge.

The shape of the external surfaces of the electrodes can be selected depending on the material composition of the object to be attracted.

The electrodes of at least one pair of electrodes can have outer surfaces that have large surface areas in order to attract metals. Typically, the electroadhesion device for metals only includes two oppositely polarized electrodes separated by a simple gap between them.

The electrodes of at least one pair of electrodes can have external surfaces that have small surface areas in order to attract non-metals.

The varying surface area of ​​the electrodes can be repetitive in the longitudinal manner along the electrodes.

Typically, the electrodes of a pair of electrodes are oppositely polarized by means of a low current with a relatively high voltage. The electrodes can be polarized by means of a direct DC voltage. The low current is typically less than 5 pA DC and the relatively high voltage more than 1500 V DC.

The base is typically made of a substance chosen to minimize leakage from the electroadhesion device, such as a substance that has a high block resistivity of at least 10¹⁶ Ω / m.

The electroadhesion device may comprise at least one electrode-formed layer and one base-formed layer. Accordingly, the base can be thin so that a layer of the electroadhesion device is defined.

The profile of the base on which the electrodes are located typically determines the profile of the electroadhesion surface. This serves to minimize, during use, air gaps between the electroadhesion surface and the object to be attracted.

In a preferred embodiment of the invention, the profile of the base on which the elec2

ES 2 272 503 T3 trodes is typically flat, but in others it can follow any profile.

The base on which the electrodes are located is typically soft. Said smoothness can be defined as having a surface variation of less than 0.01 pm.

The covering is typically as thin as possible since the electroadhesion force is inversely proportional to the distance between the electrodes and the object to be attracted. The cover can be as thin as 100 pm.

The cover can be in the form of a thin film. The film can be applied as a foil.

The coating can be applied by spraying, by bathing or by any suitable means of application.

The cover is typically made of a substance that has a high relative surface resistivity. The resistivity is typically greater than 10¹⁶ Ω.

The cover can be made of a substance that has a high dielectric constant (epsilon), typically 6.

The cover can be smooth. Said smoothness can be defined as having a surface variation of less than 0.01 pm.

Description of the drawings

The invention will now be described, by way of illustration only, with reference to the accompanying non-limiting diagrams in which

Figure 1 shows a schematic representation in a three-dimensional view of an electroadhesion device according to the invention;

Figure 2 shows a schematic representation in side view of the electroadhesion device of Figure 1;

Figure 3 shows a schematic representation in a three-dimensional view of an electroadhesion device, having a base in the form of an insulating cover, according to the invention; Y

Figure 4 shows a schematic representation in side view of the electroadhesion device of Figure 3; Y

Figure 5 shows a schematic representation of an electrode bank of an electroadhesion device in one embodiment of the invention, in which the outer surfaces of the electrodes are shaped so that they have variable surface areas so that during use , the object to be attracted can be made of a material from a variety of materials including metals and non-metals.

With reference to the drawings and to Figures 1 and 2 in particular, reference numeral 10 generally indicates an electroadhesion device according to the invention. Electroadhesion device 10 includes a base 12 and a first 14 and a second 16 banks of thin electrically conductive electrodes 18 located spaced apart from each other on one side of the base 12. Electroadhesion device 10 also includes an insulating cover 20 over the first 14 and second 16 banks so that the outer side of the insulation cover 20 defines an electroadhesion surface such that, when in use, when power is applied to the electrodes 18 and an object to be attracted is placed adjacent to the insulating cover 20, the object is attracted to the insulating cover 20 by means of a suitably high adhesion force.

Accordingly, the electroadhesion device 10 comprises a layer formed by electrodes 18 and a layer formed by the base 12, wherein the base 12 is thin so as to define a layer of the electroadhesion device 10.

The first 14 and the second 16 banks are separated by a gap 22 that is as small as possible to avoid load formation between the banks 14 and 16.

The base 12 is typically made of a substance chosen to minimize leakage from the electroadhesion device 10 such as a substance having a high block resistivity of at least 10¹⁶ Ω / m.

The profile of the base 12 determines the profile of the electroadhesive surface. Accordingly, the profile of the base 12 is shaped to correspond to the shape of a part of the object to be attracted, which part is the part that is positioned adjacent to the electro-adhesion surface. This serves to minimize, while in use, air gaps between the electroadhesion surface and the object to be attracted.

In this embodiment of the invention, the profile of the base 12 is flat, but it can be understood that in other embodiments of the invention, the profile of the base 12 can follow any profile.

Base 12 is typically smooth having a surface variation of less than 0.01 µm.

The insulating cover 20 is as thin as possible since the electro-adhesion force is, among other factors, inversely proportional to the distance between the electrodes 18 and the object to be attracted. Cover 20 is typically thinner than 100 pm.

The cover 20 is made of a substance that has a high relative surface resistivity of typically more than 10¹⁶ Ω / m and having a high dielectric constant (epsilon), typically at least 6. Cover 20 is typically made from a polymer such as nylon 6 or a PVC-based substance.

In certain embodiments of the invention, the cover 20 is in the form of a thin film that is applied as a sheet. In other embodiments, cover 20 is in the form of an enamel paint coating applied as a spray, a bath, or any other suitable means of application.

The cover 20 is smooth with a surface variation of less than 0.01 pm.

With particular reference to Figures 3 and 4, reference numeral 10.1 generally indicates an electroadhesion device according to another embodiment of the invention. Electroadhesion device 10.1 substantially resembles electroadhesion device 10 and accordingly similar reference numerals have been used to indicate the same or similar characteristics unless otherwise indicated. In this embodiment of the invention, the base is in the form of an insulating cover 20.1 as described above. Accordingly, the banks 14 and 16 are sandwiched between two covers 20, 20.1, so that the electro-adhesion device 10.1 includes two electro-adhesion surfaces.

Figure 5 shows a bank 14/16 of elongated electrodes 18 substantially parallel to one another, according to a preferred embodiment of the

ES 2 272 503 T3 invention. The adjacent electrodes 18 form a pair of electrodes to whose electrode pair energy is applied, during their use, so that they are oppositely polarized, thus causing a charge differential in a part of the object adjacent to that electrode pair, which causes a turn the object to be attracted to the electroadhesion surface.

Each of the electrodes 18 has an outer surface 24 facing and away from the base 12 whose outer surface 24 has dimensions in any direction greater than the distance from said outer surface 24 to the base 12, whose distance is the thickness of the electrode 18. Each electrode 18 is typically extremely thin so that it limits charge build-up between adjacent electrodes 18. Each electrode 18 is typically less than 5 jum thick.

Electrodes 18 are typically screen printing electrodes or vapor deposition electrodes.

Bank 14/16 is configured so that there is the least amount of air trapped between adjacent electrodes 18.

Adjacent electrodes 18 are located a fixed minimum distance 26 apart from each other which is related to a maximum withstand voltage between electrodes 18 before disruptive electrical discharge occurs. As the electroadhesion force is proportional to the voltage between adjacent electrodes, the minimum distance 26 is selected so that an appropriate voltage is achieved between an electrode pair in order to achieve a sufficient adhesion force without electrical discharge occurring. disruptive.

Electrodes 18 are shaped to limit the sharpness of the corners of electrodes 18 thereby reducing the possibility of disruptive electrical discharge.

The shapes of the outer surfaces 24 of the electrodes 18 are selected depending on the material composition of the object to be attracted.

In order to attract metals, the electrodes 18 should have outer surfaces 24 that have large surface areas. Typically, the electroadhesion device 10, 10.1 for metals only includes two oppositely polarized electrodes 18 separated by a single gap 22 between them.

In order to attract non-metals, the electrodes 18 should have outer surfaces 24 that have small surface areas.

In this embodiment of the invention, the outer surfaces 24 of the electrodes 18 are shaped such that they have varying surface areas so that when in use, the object to be attracted can be made of a variety of materials, including metals and non-metals, therefore the object is attracted with an adequate electro-adhesion force, regardless of the material. Accordingly, the outer surface 24 of each of the electrodes 18 has a linear edge on one side and a sinusoidal edge on the opposite side, so that the width of each of the electrodes varies sinusoidally by the longitudinal direction along the electrode 18, whereby the varying surface area of ​​each of the electrodes 18 is repetitive in the longitudinal direction along the electrode 18. Accordingly, the electrodes 18 are configured so that the sinusoidal edge of one of the electrodes 18.1 is aligned adjacently to the linear edge of an adjacent electrode 18.2, and so that the linear edge of one electrode 18.1 is aligned adjacently. to the linear edge of an adjacent electrode 18.3, such that the minimum distance 26 between adjacent electrodes 18 remains fairly constant.

It will be appreciated that the linear edge of one of the end electrodes 18 of the first bank 14 is positioned parallel to the linear edge of one of the end electrodes 18 of the second bank 14 on the base 12 to form the gap 22.

It will also be appreciated that in other embodiments of the invention, the electrodes 18 may be shaped and configured such that certain parts of the electroadhesion surface attract only metals, other parts attract only non-metals, and additionally other parts. attract both metals and non-metals or any combination of two of these parts.

Typically, the electrodes 18 of an electrode pair are oppositely polarized by means of a low DC current, typically less than 5 µA DC with a high DC voltage, typically more than 1500 V DC.

Additionally, it will be appreciated that in another embodiment of the invention, the electrodes 18 may be positioned on opposite sides of the base 12 when the base 12 is made of a substance having a high dielectric constant (epsilon), typically of at least 5. The electrodes 18 of an electrode pair may be placed on opposite sides of the base 12, to which pair energy is applied, during use, so that they are oppositely polarized, thus causing a charge differential in one part of the base. object adjacent to that electrode pair, which in turn causes the object to be attracted to the electroadhesion surface. Electrodes 18 on the same side of base 12 may be polarized opposite to electrodes 18 on the opposite side of base 12, thereby increasing the maximum withstand voltage between electrodes 18 and reducing the effect of impurities on the electro-adhesion surface. It will be appreciated that the electrode pair in this embodiment of the invention all have the same characteristics of an electrode pair as described with reference to the drawings except that one electrode 18 of the electrode pair is located on an opposite side of the base 12. Accordingly, the transverse relationship of the electrodes 18 of an electrode pair is altered but not the planar relationship with respect to the electroadhesion surface.

It is believed that an advantage of the invention is that a complete cost effective range can be engineered as well as viable electroadhesion devices manufactured and sold. It is further believed that it is advantageous that a wide range of objects are attracted to the electro-bonding device with adequate force to be held in place on an electro-bonding surface of the device.