WO2006133702A1

WO2006133702A1 - An object comprising a layered structure of alternating conducting and insulating layers

Info

Publication number: WO2006133702A1
Application number: PCT/DK2006/000333
Authority: WO
Inventors: Claus Ladefoged Knudsen; Ken Allan Mathiasen; Torben Melchior Hansen; Lars Pleth Nielsen
Original assignee: Danfoss A/S
Priority date: 2005-06-15
Filing date: 2006-06-13
Publication date: 2006-12-21
Also published as: EP1896803A1

Abstract

An object adapted to have a sensor element (5) mounted thereon, the object comprising a body part (1 ) with a layered structure of alternating coating layers of conducting (6) and insulating or semiconducting (11 ) material. The coating layer(s) of conducting material (6) is/are applied in a pattern establishing conductive path(s) between a first part adapted to carry a sensor element (5) and a second part adapted to establish connection to exterior equipment. The conductive path(s) is/are arranged along an exterior surface of the body (1 ). Thereby a connection may be established between a sensor element (5) arranged inside a closed system and the exterior of the closed system without the need for separate feed through connections. Suitable for use in closed systems, such as hydraulic systems, where it is desired to measure various parameters, such as pressure or temperature. Furthermore, a method of forming the object.

Description

AN OBJECT COMPRISING A LAYERED STRUCTURE OF ALTERNATING CONDUCTING AND INSULATING LAYERS

FIELD OF THE INVENTION

The present invention relates to an object adapted to have a sensor element mounted thereon and to provide an electrical connection to such a sensor element. The invention further relates to a fabrication method of forming such an object.

BACKGROUND OF THE INVENTION

Normally, a sensor will comprise a sensor element, a housing, signal wires for communicating signals to/from the sensor element, and an electrical terminal. In case the sensor is to be used in closed systems, such as pressure sensors or temperature sensors in hydraulic systems, it is necessary to provide signal wires between the exterior and the interior of the closed system in order to communicate signals to/from the sensor element positioned inside the closed system. This is typically provided by means of feed through connections. Such feed through connections have to fulfil strict requirements in terms of tightness, mechanical strength, etc., and they are therefore technically relatively difficult to make, and there is a potential risk that a given feed through connection will not fulfil the specified requirements. Furthermore, the technical difficulties add to the costs of the sensor, and often the costs related to housing, connectors, wires, etc. by far exceeds the costs related to the actual sensor element. A typical feed through connection is a so-called glass connection, in which a number of pins are encapsulated in a glass material, the pins providing the desired connections, and the glass material providing the desired properties in terms of tightness, mechanical strength, etc. US 5,452,087 discloses a method and apparatus for measuring pressure with embedded non-intrusive fibre optics. A Fabry-Perot interferometer is arranged in a terminated, single mode fibre to function as a strain gauge. The interferometer may be embedded along the axis of a metal bolt. Thereby it is possible to non-intrusively measure the pressure inside a vessel. However, the apparatus of US 5,452,087 does not solve the general problems related to communicating signals to/from a sensor element positioned inside a closed system, since the sensor principle disclosed in US 5,452,087 is based on pure optical signal processing in relation to changes in the resonances of the Fabry-Perot interferometer.

US 6,521 ,830 discloses a housing for electrical or electronic devices or components comprising a moulding of thermoplastic material which has at selected locations on its surface electrical conductor tracks with contact pins attached at predetermined locations, the conductor tracks being covered with a layer of thermoplastic material. Sensing devices may be mounted on the contact pins. The conductor tracks provide electrical connections to/from such sensing devices through a wall of the housing. Accordingly, it is not possible to replace a sensing device, i.e. the entire housing must be discarded if a sensing device malfunctions or another kind of sensing device is desired. Furthermore, the housing is relatively cumbersome to manufacture. Finally, it is necessary to customize the housing specifically to the intended application, i.e. it is not possible to use the same housing for a number of different applications. Thereby it is not possible to mass produce one device for several applications.

SUMMARY OF THE INVENTION

It is, thus, an object of the invention to provide electrical connections to a sensor element positioned inside a closed system without the need for traditional wires. It is a further object of the invention to provide a standard object onto which a desired sensor element may be mounted in such a way that signals can be communicated to/from the sensor element via the standard object.

It is an even further object of the invention to provide an object which is capable of providing signal communication to the interior of another object or structure.

It is an even further object of the invention to provide signal communication to/from a sensor element positioned inside a closed system in a cost effective manner.

It is an even further object of the invention to provide signal communication to/from a sensor element positioned inside a closed system in a manner which fulfils requirements in terms of tightness while providing the necessary mechanical strength.

It is an even further object of the invention to provide a method of forming an object as described above in a cost effective manner.

According to a first aspect of the invention the above and other objects are fulfilled by providing an object adapted to have a sensor element mounted thereon, the object comprising:

- a body being made from an insulating or from a conducting material, said body having an exterior surface enclosing the body,

- a first coating layer with a pattern of conducting material,

- a second coating layer of an insulating or semiconducting material at least substantially covering a surface area of the body, said first and second coating layers being arranged on the exterior surface of the body in such a way that a layered structure of alternating layers of conducting and insulating or semiconducting material is formed, the object thereby being capable of communicating an electrical signal from a first part of the exterior surface of the body, said first part being adapted to carry a sensor element, to a second part of the exterior surface part of the body, via the pattern of conductive material.

The sensor element which may be mounted on the object may be any kind of sensor element appropriate for the kind of measurement which it is desired to perform. It may, thus, be or comprise an accelerometer, an anglemeter, a barometer, a chemical sensor, a light sensor, e.g. a colour sensor, a conductivity sensor, an ammeter, a Hall probe, a fire detector, e.g. a smoke sensor, a flowmeter, a Newtonmeter, a gas sensor, such as a λ sensor, a gauge, a thermometer, a moisture sensor, e.g. a humidity sensor or a dew point sensor, a motion sensor, a pH sensor, a position sensor, e.g. a level sensor, a displacement sensor, a tilt sensor or a gyroscope, a pressure sensor, e.g. a vacuum gauge, a strain gauge, a vibration sensor, a viscosity sensor, a weight, a voltmeter, etc. The object is preferably made in such a way that it is possible to mount any of a number of standard sensor elements on the object. This may be achieved by designing the first part of the object with a 'standard footprint' adapted to receive whichever sensor element is suitable for a specific application. Thereby the object is a standard object which can be used for a number of various applications, and it is therefore possible to produce larger series of the object, thereby reducing the overall manufacturing costs. Furthermore, it may be possible for an end user to exchange the sensor element, and the object may thereby be potentially reusable. Alternatively, the sensor element may be at least substantially fixedly mounted on the object by the manufacturer. However, in this case it is still possible for the manufacturer to manufacture the object (or at least the body) as a standard object onto which various sensor elements may be mounted. Alternatively, the object may be used whenever signal transfer is needed between the interior and the exterior of a closed system.

The body is a relatively large part compared to the total size of the object. Thus, the part may at least substantially define the shape and size of the object. Depending on the application, it is either made from a conducting material or from an insulating or semiconducting material. In case the body is made from a conducting material it may advantageously be made from a metal, such as copper, brass or steel, or from a carbon containing material.

In case the body is made from an insulating material it may advantageously be made from a plastics material, such as various types of polymers, or from a ceramic material, such as a binary or a tertiary ceramic material.

The first coating layer has a pattern of conducting material. Thus, the conducting material preferably covers only part of the exterior surface of the body in order to avoid short circuiting between the various parts of the pattern, and it may be arranged in any suitable pattern, such as a number of substantially parallel lines arranged on a surface area of and along the direction of a longitudinal axis of the body. Alternatively, the pattern may be any other suitable pattern, as long as the conducting pattern is arranged on the exterior surface of the body in such a way that at least one conducting connection is established between the first part and the second part of the exterior surface of the body, the pattern of conductive material thereby being capable of communicating an electrical signal between the first part and the second part.

The exterior surface encloses the body. Thus, the exterior surface defines a boundary between the body and the surroundings. The first and second coating layers are arranged on the exterior surface, and thereby the electrical signals may be communicated along the exterior surface, as opposed to being communicated through the body. This is an advantage because it allows for easy and cost effective manufacture of the object. Furthermore, it makes the object suitable for insertion in a structure, thereby providing electrical connections to the interior of that structure. Finally, it is possible to replace an object inserted in a structure, e.g. because of a malfunction in a sensing device mounted on the object or in an electrical path of the object, or because another kind of sensing device is desired.

The first coating layer is relatively thin as compared to the size of the body. Thus, the first coating layer preferably has a thickness within the interval 0.005 μm to 200 μm, such as in the interval 0.01 μm to 100μm, such as in the interval 0.5 μm to 50 μm, such as in the interval 10 μm to 30 μm, such as approximately 20 μm, alternatively within the interval 0.2 μm to 1 μm. This is, of course, the thickness of the layer in the positions where pattern of conducting material is present.

The conducting material may be formed by a single element, or it may be a combination of one or more elements, at least one of the elements being conducting, e.g. in the form of an alloy. Thus, the conducting material may be or comprise gold, silver, titanium, zirconium, chromium, molybdenum, tungsten, iron, nickel, palladium, platinum, copper, zinc, aluminium, and/or carbon. In one embodiment the conductive material may be composed of conducting or superconducting ceramics.

The second coating layer is made from an insulating or semiconducting material, and it at least substantially covers a surface area of the body. Thus, the second coating layer covers area parts which are covered by the pattern of conducting material as well as areas not covered by this pattern. The second coating layer is also relatively thin as compared to the size of the body. Thus, the first coating layer preferably has a thickness within the interval 0.005 μm to 200 μm, such as in the interval 0.01 μm to 100μm, such as in the interval 0.5 μm to 50 μm, such as in the interval 10 μm to 30 μm, such as approximately 20 μm, alternatively within the interval 0.2 μm to 1 μm.

The second coating layer may be made from an insulating or a semiconducting material. Alternatively, it may be made from a material having a relatively high resistivity, i.e. a resistivity which is substantially higher than the resistivity of the conducting material of the first coating layer. Thereby conductance of electrical signals in the second coating layer is avoided. The material may be made from a single element, or from a mixture of one or more elements. The second coating layer may be or comprise an electrically insulating oxide or a nitride, such as AI₂O₃, SiO₂, AIN, ZnO₂, and/or other suitable oxides or nitrides or mixtures hereof being known to persons skilled in the art of insulating materials. In one embodiment the second coating layer may be made from a non- stoichiometric oxide or nitride or mixtures thereof. Alternatively, the second coating layer may be formed by an organic layer or a suitable type of paint.

The first and second coating layers are arranged on the exterior surface of the body in such a way that a layered structure of alternating layers of conducting and insulating or semiconducting material is formed. Thus, in case the body is made from a conducting material, the second coating layer (which is insulating or semiconducting) should be arranged immediately on the surface of the body, the first coating layer being arranged on top of the second coating layer. Thereby the second coating layer (insulating or semiconducting) will be sandwiched between two structures of conducting material, i.e. the body and the first coating layer, and thereby an alternating layered structure is provided.

Similarly, if the body is made from an insulating material, the first coating layer should be arranged immediately on the body with the second coating layer arranged on top of the first coating layer. In this case the first coating layer (conducting) will be sandwiched between two insulating or semiconducting structures, i.e. the body and the second coating layer, and the alternating layered structure is thereby formed.

The fact that an electrically conducting path can be provided from the first part of the exterior surface of the body to the second part of the exterior surface of the body merely by coating the body with alternating layers of conducting and insulating/semiconducting material makes it possible to communicate signals to and from a sensor element mounted on the first part of the object without the need for traditional wiring, traditional feed through connections, etc. The object can easily be produced in a cost effective manner. Furthermore, the first part may be made as a 'standard footprint', thereby allowing any desirable kind of sensor element to be mounted on the object, the signal communication being independent of the kind of sensor element selected. This is a great advantage.

The object may further comprise at least one additional first coating layer and/or at least one additional second coating layer arranged on the exterior surface of the body in such a way that a layered structure of alternating layers of conducting and insulating or semiconducting material is formed. Thus, as many layers as desired may be applied to the object, as long as the alternating layered structure is maintained.

The object may further comprise a sensor element mounted on the body. In this case the layered structure may preferably be arranged in such a way that it also at least partly covers the sensor element. In this embodiment the sensor element is preferably mounted by the manufacturer before the coating layers are applied. Thus, when the coating layers are applied they will also cover the sensor element, and the sensor element becomes an integrated part of the object. Alternatively, the object may be produced without the sensor element, the object thereby being a standard element onto which a desired kind of sensor element may be mounted.

The object may further comprise a wear resistant outer layer formed on the outermost layer of the layered structure. Such a layer provides protection to the coating layers and, optionally, to a sensor element mounted on the object. This is an advantage in case the object is to be fitted tightly into an opening or the like, e.g. by means of mating threads on the object and in the opening. In one embodiment the wear resistant outer layer may be formed from a material known in the field of tribology, such as binary nitrides, e.g. CrAIN, TiAIN/CrN, Diamond Like Carbon (DLC), or mixtures thereof. In case the outermost layer of the layered structure is conducting, the wear resistant layer should preferably be insulating and vice versa.

As mentioned above, in case the object has a sensor element mounted on the body, the wear resistant outer layer preferably further covers the sensor element, thereby providing protection for the sensor element.

The object may further comprise one or more terminal pins arranged at or near the second part of the body and in communication with the pattern of conductive material, thereby providing an exterior connection to a sensor element mounted on the body. The terminal pin(s) may advantageously be in the form of standard connectors to external equipment, such as equipment for processing and/or displaying signals received from a sensor element and/or equipment for generating signals, e.g. control signals, for a sensor element.

The body may comprise a threaded portion having an outer thread. Thus, the body may be a standard bolt adapted to be screwed into a mating thread in an opening, thereby providing an at least substantially tight fit between the object and an external structure, e.g. a wall part of a closed system. The fit may be further tightened by means of one or more gaskets, such as one or more o-rings. It is advantageous to be able to manufacture the object as a standard bolt with appropriate coatings applied thereto, because it makes the manufacturing process as well as the fitting process very simple and thereby cost effective. Furthermore, an ordinary bolt which is needed for the closed system anyway could be replaced by an object according to the invention with a desired sensor element mounted thereon. Thereby desired measurements can be obtained from inside the closed system without the need for any additional parts or feed through connections. In case the object is a bolt, the first part is preferably located at or near a threaded end part of the bolt, and the second part is preferably located at or near the bolt head. Thereby a sensor element can be mounted at or near the threaded end part which will normally be the part which is inserted into a closed system while the bolt head part is used for tightening the bolt. The bolt head (and thereby the second part) will, accordingly, normally be positioned outside the closed system, and the pattern of conducting material thereby provides a connection between a sensor element positioned inside the closed system and the exterior of the closed system without the need for separate feed through connections.

In one embodiment of the invention the object may be a bolt with buried conducting layers arranged on a surface area of the bolt. The bolt may be used as an online sensor for monitoring tension strain when tightening a bolt, nut or work piece, etc. This may, e.g., be obtained by an online monitoring of a capacitance, resistance or impedance when tightening the bolt. This will provide a standard method for measuring stress/strain online when tightening delicate equipment.

Alternatively, the buried conducting layers arranged on the surface area of the bolt may be used as signal transmitters or power transfers between the interior and exterior of a closed system, through a standard bolt opening.

In case the body is made from a conducting material, the body may provide a conductive path. In this embodiment the body itself may be used to provide large currents to or from the interior part of a closed system. The second coating layer ensures that such currents are solely conducted via the body itself.

As described above, the object may advantageously form a feed through connection to a sensor element mounted on the object. This is obtained without the disadvantages described above.

According to a second aspect of the invention the above and other objects are fulfilled by providing a method of forming an object for communicating an electrical signal from a first part of the object to a second part of the object, the method comprising the steps of:

- providing a body from an insulating or from a conducting material, said body having an exterior surface enclosing the body,

- providing a first coating layer with a pattern of conducting material,

- providing a second coating layer of an insulating or semiconducting material at least substantially covering a surface area of the body, wherein the steps of providing said first and second coating layers are performed in such a way that the resulting layers are arranged on the exterior surface of the body in such a way that a layered structure of alternating layers of conducting and insulating or semiconducting material is formed.

Thus, the second aspect of the invention provides a method for manufacturing an object according to the first aspect of the invention.

It should be noted that a skilled person would readily recognise that any feature described in connection with the first aspect of the invention may also be combined with the second aspect of the invention, and vice versa.

The step of providing a first coating layer and/or the step of providing a second coating layer may be performed by means of sputtering, chemical vapour deposition (CVD) or electroplating. In this case the method may further comprise the step of performing a post chemical treatment on the first and/or the second coating layer. Such a post chemical treatment may, e.g., be or comprise anodization, oxidation, nitridation, etc. Further information on specific coating techniques may, e.g., be found in 'Handbook of Advanced Plasma Processing Techniques', R. J. Shul, S. J. Pearton, Springer, and in references mentioned therein. Alternatively, the step of providing a first coating layer and/or the step of providing a second coating layer may be performed by means of spraying or by means of an ink jet technique, the latter being particularly useful for providing the first coating layer, since the ink jet technique is suitable for forming the relevant conducting pattern.

The method may further comprise the step of mounting a sensor element at or near the first part of the object, in which case the steps of providing the first and second coating layers may be performed in such a manner that the resulting layered structure covers the sensor element. Alternatively or additionally, the method may further comprise the step of providing a wear resistant outer layer on the outermost layer of the layered structure. This has already been described above.

The method may further comprise the step of providing one or more terminal pins at or near the second part of the object and in communication with the pattern of conductive material. This may, e.g., be performed by pressing the pin(s) into the second part of the object. In one embodiment the pin(s) may be fitted into a plastic housing, and the plastic housing along with the pin(s) may subsequently be mounted directly onto the object.

Because the terminal pin(s) is/are in communication with the pattern of conductive material, one or more electrically conducting paths are formed between the terminal pin(s) and a sensor element mounted on the first part of the object. Thereby the terminal pin(s) may establish one or more connections between the object and external equipment for processing a signal received from the sensor element and/or for displaying measured parameters and/or for generating signals to the sensor element. The terminal pin(s) may preferably be in the form of a standard connector for such equipment, thereby making it very easy to mount and plug in the object when it is desired to position a sensor element inside a closed system.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be further described with reference to the accompanying drawings in which:

Fig. 1 is a perspective view of a bolt according to an embodiment of the invention, Fig. 2 is an exploded view of the bolt of Fig. 1 , and

Figs. 3a-3e are a cross sectional views of an object according to an embodiment of the invention and illustrating a method according to an embodiment of the invention.

DETAILED DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective view of a bolt 1 according to an embodiment of the invention. The bolt 1 has a threaded portion 2, a bolt head 3 and an end part 4 arranged opposite the bolt head 3. At the end part 4 a sensor element 5 is mounted. Along the threaded portion 2 a pattern of conducting material 6 is arranged in parallel lines establishing a connection between the end part 4 and the bolt head 3. The pattern of conductive material 6 is, thus, arranged on an exterior surface of the bolt 1. Thereby electrical signals can be communicated between the sensor element 5 and the bolt head 3 via the pattern of conducting material 6. Thus, in the embodiment shown in Fig. 1 , the first part of the object is a region comprising the end part 4 of the bolt 1 , and the second part of the object is a region comprising the bolt head 3.

When in use, the bolt 1 can be fitted into an opening, e.g. in a wall portion of a closed system, such as a hydraulic system. The bolt 1 is preferably fitted in the opening in such a way that the end part 4 carrying the sensor element 5 is positioned inside the closed system while the bolt head 3 is positioned outside the closed system. If appropriate connections are fitted at the bolt head 3 it is thereby possible to communicate signals to/from the sensor element 5 from/to the exterior of the closed system, via the pattern of conductive material 6, i.e. without the requirement of separate feed through connections and/or wiring. In Fig. 1 a connector box 7 for communicating a received signal further on to an external device is visible. The bolt 1 of Fig. 1 is further provided with an o-ring 8 in order to ensure a tight fit when the bolt 1 is fitted into an opening as described above.

Fig. 2 is an exploded view of the bolt 1 of Fig. 1 for a clearer view of the individual parts. The bolt 1 and its function have already been described above, and will therefore not be described here.

Fig. 2 further shows that the connector box 7 comprises four terminal pins 9. One end of each pin 9 is fitted into the bolt head 3, and the protruding part is encapsulated in the connector box 7, which is attached to the bolt head 3 by means of a screw 10. Thereby the bolt head 3 has been provided with a standard terminal connector which can be used for connecting the sensor element 5 to an exterior device. The exterior device may be used for analysing measurement signals received from the sensor element 5 and/or for generating control signals for the sensor element 5.

Fig. 3a is a cross sectional view of part of an object according to an embodiment of the invention in the form of a bolt 1 having a bolt head 3 and an end part 4 onto which a sensor element (not shown) may be mounted. The bolt 1 further comprises a threaded portion 2. The bolt 1 is made from an electrically conducting material.

Fig. 3b is a cross sectional view of the bolt 1 of Fig. 3a. However, in Fig. 3b the bolt 1 has further been provided with a layer of insulating material 11. The layer of insulating material 11 at least substantially covers the complete outer surface area of the bolt 1.

Fig. 3c is a cross sectional view of the bolt 1 of Figs. 3a and 3b. In Fig. 3c the bolt 1 has further been provided with a layer of conducting material 6. The layer of conducting material 6 has been applied to the outer surface of the bolt 1 , on top of the layer of insulating material 11 , in a pattern as illustrated in Figs. 1 and 2. Thus, the layer of conductive material 6 does not cover the complete outer surface of the bolt 1. The layer of insulating material 11 arranged between the initial bolt 1 (which is made from an electrically conducting material) and the layer of conducting material 6 prevents short circuiting of the conducting paths formed by the pattern of conducting material 6.

Fig. 3d is a cross sectional view of the bolt 1 of Figs. 3a-3c. In Fig. 3d the bolt 1 has further been provided with an additional layer of insulating material 11 on top of the layer of conducting material 6. This additional layer of insulating material 11 prevents short circuiting of the conducting paths formed by the pattern of conducting material 6 in case the bolt 1 is positioned in contact with conducting material, e.g. in case the bolt 1 is screwed into a conducting structure.

Fig. 3e is a cross sectional view of the bolt 1 of Figs. 3a-3d. In Fig. 3e the bolt 1 has further been provided with a layer of wear resistant material 12 on top of the outermost layer of insulating material 11. The layer of wear resistant material 12 makes the bolt 1 suitable for being inserted into an opening having a mating thread portion, thereby providing a close fit between the bolt 1 and a structure in which the opening is arranged. Due to the layer of wear resistant material 12 the bolt 1 can be fitted into the opening without risking damage to the layers 6, 11 positioned beneath the wear resistant layer 12.

Figs. 3a-3e thereby illustrate a method of forming an object according to an embodiment of the invention by sequentially applying layers of insulating material 11 and layers of conducting material 6. Thereby a layered structure of alternating layers of conducting 1 , 6 and insulating 11 material is formed. Finally, the layered structure is covered by a layer of wear resistant material 12.

Claims

1. An object adapted to have a sensor element (5) mounted thereon, the object comprising:

- a body (1) being made from an insulating or from a conducting material, said body (1 ) having an exterior surface enclosing the body (1),

- a first coating layer (6) with a pattern of conducting material,

- a second coating layer (11 ) of an insulating or semiconducting material at least substantially covering a surface area of the body (1 ),

said first (6) and second (11 ) coating layers being arranged on the exterior surface of the body (1) in such a way that a layered structure of alternating layers of conducting and insulating or semiconducting material is formed, the object thereby being capable of communicating an electrical signal from a first part of the exterior surface of the body (1 ), said first part being adapted to carry a sensor element (5), to a second part of the exterior surface of the body (1 ), via the pattern of conductive material.

2. An object according to claim 1 , further comprising at least one additional first coating layer (6) and/or at least one additional second coating layer (11) arranged on the exterior surface of the body (1 ) in such a way that a layered structure of alternating layers of conducting and insulating or semiconducting material is formed.

3. An object according to claim 1 or 2, further comprising a sensor element (5) mounted on the body (1 ), the layered structure being arranged in such a way that it also at least partly covers the sensor element (5).

4. An object according to any of the preceding claims, further comprising a wear resistant outer layer (12) formed on the outermost layer of the layered structure.

5. An object according to claim 4, the object having a sensor element (5) mounted on the body (1 ), wherein the wear resistant outer layer (12) further covers the sensor element (5), thereby providing protection for the sensor element (5).

6. An object according to any of the preceding claims, further comprising one or more terminal pins (9) arranged at or near the second part of the body (1 ) and in communication with the pattern of conductive material, thereby providing an exterior connection to a sensor element (5) mounted on the body (1 ).

7. An object according to any of the preceding claims, wherein the body (1 ) comprises a threaded portion (2) having an outer thread.

8. An object according to any of the preceding claims, wherein the body (1 ) is made from a conducting material, and wherein the body (1) provides a conductive path.

9. An object according to any of the preceding claims, wherein the object forms a feed through connection to a sensor element (5) mounted on the object.

10. An object according to any of the preceding claims, wherein the first (6) and/or the second (11 ) coating layer is/are formed by means of sputtering, chemical vapour deposition, electroplating, spraying or ink jet printing.

11. A method of forming an object for communicating an electrical signal from a first part of the object a second part of the object, the method comprising the steps of:

- providing a first coating layer with a pattern of conducting material,

- providing a second coating layer of an insulating or semiconducting material at least substantially covering a surface area of the body,

wherein the steps of providing said first and second coating layers are performed in such a way that the resulting layers are arranged on the exterior surface of the body in such a way that a layered structure of alternating layers of conducting and insulating or semiconducting material is formed.

12. A method according to claim 11 , wherein the step of providing a first coating layer and/or the step of providing a second coating layer is/are performed by means of sputtering, chemical vapour deposition, electroplating, spraying or ink jet printing.

13. A method according to claim 12, further comprising the step of performing a post chemical treatment on the first and/or the second coating layer.

14. A method according to any of claims 11-13, further comprising the step of mounting a sensor element at or near the first part of the object, wherein the steps of providing the first and second coating layers are performed in such a manner that the resulting layered structure covers the sensor element.

15. A method according to any of claims 11-14, further comprising the step of providing a wear resistant outer layer on the outermost layer of the layered structure.

16. A method according to any of claims 11-15, further comprising the step of providing one or more terminal pins at or near the second part of the object and in communication with the pattern of conductive material.

17. A method according to claim 16, wherein the step of providing one or more terminal pins comprises pressing the pin(s) into the second part of the object.