DE102010030034A1 - Actuator for use in e.g. automobile industry, has electrodes, and groups of nanotubes, which are in parallel connection between force transmission elements in mechanical manner, where groups are electrically subjected opposite to each other - Google Patents

Abstract

The actuator (1) has electrodes, and two force transmission elements (4, 5) at which two groups (8, 9) of nanotubes (10-1 to 10-3, 11-1 to 11-4) i.e. carbon nanotubes, are supported. One group of the nanotubes is electrically subjected opposite to the other group of nanotubes. The groups of the nanotubes are in parallel connection between the transmission elements in a mechanical manner. The transmission elements are designed as planar plates (6, 7), where an effective direction and a drawing direction of the nanotubes are oriented transverse to an extension plane of the planar plates.

Description

TECHNICAL FIELD OF THE INVENTION

The invention relates to an actuator with two power transmission elements, on which are supported electrically charged nanotubes.

STATE OF THE ART

Nanotubes are tubes with a diameter of less than 100 nanometers up to diameters of a few Angstrom. The length of such nanotubes is for example between a few micrometers to several centimeters. Nanotubes made of carbon are known, whereby nanotubes of boron nitride, sulfides (molybdenum and tungsten disulfide, copper sulfide), metal oxides (eg V ₂ O ₅ ) and halides (nickel, chloride, cadmium chloride, cadmium iodide) can be used. In principle, all tube-shaped materials can be used, the application of electrical variables such. B. voltage or current show a mechanical deflection. As far as the term "bucky paper" is used below, this includes not only layers of carbon nanotubes, but also layers of any other nanotubes. The nanotubes may be single-walled nanotube or SWNT or multi-walled nanotube or MWNT, wherein the wall may form a closed ring or a spiral-like structure, and ends of the tubes may be closed or opened can be with empty or filled inside.

From the state of the art

• Gao, M.; Dai, L.; Baughman, R. H.; Spinks, G. M.; Wallace, G. G.: Electrochemical properties of aligned nanotube arrays: basis of new electromechanical actuators; Proc. of SPIE, Vol. 3987, Electroactive Polymer Actuators and Devices (EAPAD), ed. Y. Bar-Cohen (März 2000) [1]

ist eine Herstellung eines Stellelementes für einen Aktuator bekannt, bei welchem einzelne Nanotubes mit einem durchschnittlichen Durchmesser von 30–80 nm und mit einer Länge von 10 μm senkrecht zu einem Quarz-Substrat ausgerichtet werden. Derartige ”Blätter” werden vorbereitet durch eine Pyrolyse von Eisen (II) Phthalocyanin, FeC₃₂N₈H₆ (FePc) unter Ar/H₂ bei 800 bis 1100°C entsprechend einem Verfahren, welches aus der Literaturstelle Shaoming, Huang, Liming Dai, Albert W. H. Mau, J. Phys. Chem. B. 1999, 103, 4223 bekannt ist. Vor einer Entfernung des Quarz-Substrates von den ausgerichteten Nanotubes in einer HF/H₂O-Lösung wird eine dünne Goldschicht auf der amorphen Carbonschicht angeordnet, die an einem oberen Ende der Nanotubes gewachsen ist, wodurch eine Verbindung der Nanotubes miteinander erfolgt und ein leitendes Substrat bereitgestellt wird. Die einzelnen Nanotubes werden dann in einem Aktuator über das Gold-Subtrat gleichermaßen elektrisch beaufschlagt was dazu führt, dass benachbarte Nanotubes von einander abgestoßen werden. Infolge der biegeweichen Ausgestaltung des Gold-Substrates führen diese Abstoßungskräfte zu einer Verformung des Gold-Substrates, so dass eine anfängliche ebene Ausrichtung des Gold-Substrates mit zunehmender elektrischer Beaufschlagung zu einem bogenförmigen Gold-Substrat reversibel umgeformt wird.

• Gao, M .; Dai, L .; Baughman, RH; Spinks, GM; Wallace, GG: Electrochemical properties of aligned nanotube arrays: basis of new electromechanical actuators; Proc. of SPIE, Vol. 3987, Electroactive Polymer Actuators and Devices (EAPAD), ed. Y. Bar-Cohen (March 2000) [1]

For example, it is known to manufacture an actuating element for an actuator in which individual nanotubes having an average diameter of 30-80 nm and a length of 10 μm are aligned perpendicular to a quartz substrate. Such "sheets" are prepared by pyrolysis of ferrous phthalocyanine, FeC ₃₂ N ₈ H ₆ (FePc) under Ar / H ₂ at 800 to 1100 ° C according to a method which is known from the literature Shaoming, Huang, Liming Dai, Albert WH Mau, J. Phys. Chem. B 1999, 103, 4223 is known. Prior to removal of the quartz substrate from the aligned nanotubes in an HF / H ₂ O solution, a thin layer of gold is placed on the amorphous carbon layer grown at an upper end of the nanotube, thereby connecting the nanotubes to each other and conducting Substrate is provided. The individual nanotubes are then electrically charged in an actuator via the gold substrate so that adjacent nanotubes are repelled from each other. As a result of the flexurally soft design of the gold substrate, these repulsion forces lead to a deformation of the gold substrate, so that an initial planar alignment of the gold substrate is reversibly converted to an arcuate gold substrate with increasing electrical impingement.

On the other hand is off

• H. P. Monner, S. Mühle, P. Wierach, J. Riemenschneider: Carbon Nanotubes – ein multifunktionaler Leichtbauwerkstoff für die Adaptronik, Adaptronic Congress 2003, 01.–03. April 2003 [2] und
• J. Riemenschneider, T. Mahrholz, J. Mosch, H. P. Monner, J. Melcher: Carbon Nanotubes – Smart Material of the Future: Experimental Investigation of the System Response; II Eccomas Thematic Conference an Smart Structures and Materials C. A.; Mota Soares et al. (Eds.), Lissabon, Portugal, 18.–21. 07. 2005 [3]

der Einsatz von so genannten ”Bucky-Papers” bekannt, bei denen es sich um Carbon-Nanotubes handeln, die aus statistisch verteilten Carbon-Nanotube-Bündeln bestehen und die in der Art eines Vlies durch Vakuumfiltration hergestellt sind. Bei derartigen Bucky-Papers besteht nur eine schwache Haftung zwischen den einzelnen Nanotubes, so dass diese spröde Materialeigenschaften aufweisen. Zur elektrischen Aktivierung eines Bucky-Papers müssen Ionen an den einzelnen Nanotubes angelagert werden. Hierzu werden diese mit einem Elektrolyt umgeben, beispielsweise einer einmolaren NaCl-Lösung. Wandern Ionen durch den Elektrolyten zu dem Bucky-Paper und orientieren sich um Nanotubes oder ordnen sich um die Nanotubes herum ab, dehnen sich die Nanotubes durch eine elektrochemische Wechselwirkung mit den Ionen aus. Zum Aufbau eines Aktuators wird ein doppelseitiges Klebeband beidseitig mit Bucky-Paper versehen. Die beiden Bucky-Paper werden entgegengesetzt zueinander mit einem Pluspol und einem Minuspol einer Spannungsquelle verbunden. Dies führt bei Einsatz in einem Elektrolyt dazu, dass sich die Bucky-Paper unterschiedlich stark verlängern, wobei sich die mit dem Klebeband gebildete Struktur krümmt.

• HP Monner, S. Mühle, P. Wierach, J. Riemenschneider: Carbon Nanotubes - a Multifunctional Lightweight Material for Adaptronics, Adaptronic Congress 2003, 01.-03. April 2003 [2] and
• J. Riemenschneider, T. Mahrholz, J. Mosch, HP Monner, J. Melcher: Carbon Nanotubes - Smart Materials of the Future: Experimental Investigation of the System Response; II Eccoma's Thematic Conference on Smart Structures and Materials CA; Mota Soares et al. (Eds.), Lisbon, Portugal, 18.-21. 07. 2005 [3]

the use of so-called "Bucky-Papers" known, which are carbon nanotubes, which consist of randomly distributed carbon nanotube bundles and which are produced in the manner of a nonwoven by vacuum filtration. In such Bucky papers, there is only a weak adhesion between the individual nanotubes, so that they have brittle material properties. For electrical activation of a Bucky paper, ions must be attached to the individual nanotubes. For this purpose, they are surrounded by an electrolyte, for example a one-molar NaCl solution. When ions migrate through the electrolyte to the bucky paper and orient themselves around nanotubes or align around the nanotubes, the nanotubes expand through an electrochemical interaction with the ions. For setting up an actuator, a double-sided adhesive tape is provided on both sides with Bucky paper. The two Bucky papers are connected opposite to each other with a positive pole and a negative pole of a voltage source. When used in an electrolyte, this causes the bucky-papers to extend to different extents, whereby the structure formed by the adhesive tape curves.

According to the structure of an actuator known from [3], a bucky paper is used, which is used in an electrolyte as an electrode and is prestressed in the longitudinal direction. Farther Are used in the electrolyte, a counter electrode and a reference electrode. By applying an electrical charge to the electrode formed with the bucky-paper, the longitudinal extension of the actuator changes, which can be detected with a laser according to [3]. Furthermore, in [3] opportunities for improving the macroscopic structure of the carbon nanotube are addressed. Improved structural properties should be achieved by producing carbon nanotube fibers or by reinforced nanotube bundles with bridges between the individual nanotubes, cf. also in this respect in [3]. addressed references. Furthermore, in the outlook, the use of a solid-phase electrolyte for a carbon nanotube-based actuator is addressed.

Out DE 102 44 312 A1 It is known to produce modified bucky-paper in which individual nanotubes have a preferred direction, so that the nanotubes substantially at an angle less than 90 °, preferably less than 60 ° or even less than 45 ° aligned to a parallel arrangement are. Here, the preferred direction lies in the plane of the Bucky paper. Furthermore, it is off DE 102 44 312 A1 a structure of an actuator with a plurality of each formed with a bucky-paper control elements, in which the preferred direction of the nanotube is oriented transversely to the direction of adjustment of the actuator.

Out WO 2000/050771 An actuator is known in which individual adjusting elements are based on the curvature of oppositely electrically charged leaves, wherein a plurality of such adjusting elements are mechanically connected one after the other in order to achieve an actuator with increased possibilities of the achievable actuating movements.

Out DE 10 2004 025 603 A1 An actuator is known in which unidirectionally oriented nanotubes are arranged in a plurality of layers connected in series between webs orthogonal to the webs. There is an electrically conductive connection between the nanotubes and the bars. A mechanical connection of the nanotubes to the webs takes place on both sides by a cohesive connection. For this purpose, a metal carbide can be formed at contact points between the nanotubes and the webs by a solid-state reaction, which connects the nanotubes and the webs with each other in a mechanically loadable manner. To further improve a connection and contacting the contact points between nanotubes and webs can be additionally coated with a metal, whereby, for example, the ends of the nanotubes are completely embedded in metal carbide after the previously described solid-state reaction.

Out WO 03/061107 A2 and Fukuda T. et al .: Perspective of Nanotube Sensors and Nanotube Actuators. In: 4th IEEE Conference on Nanotechnology, 2004, pp. 41-44 Further actuators are known in which nanotubes are aligned unidirectionally and are firmly bonded to conductive plates or electrodes.

Further state of the art with regard to the structural design of actuators with nanotubes, the connection of which with each other and the electrical contacting DE 10 2005 034 323 A1 refer to.

OBJECT OF THE INVENTION

• – des Gewichts,
• – der elektrischen Kontaktierung und/oder
• – der erzielbaren Kräfte und Verschiebungen

verbesserten Aktuatorkonzept vorzuschlagen.The invention is based on the object, a nanotube-based actuator with a particular regard

• - the weight,
• - the electrical contact and / or
• - the achievable forces and shifts

to propose an improved actuator concept.

SOLUTION

The object of the invention is achieved with the features of independent claim 1. Further embodiments of this solution will become apparent according to the features of the dependent claims 2 to 8.

DESCRIPTION OF THE INVENTION

The present invention is based on the finding that known actuator concepts, in particular based on carbon nanotubes ("carbon nanotubes", in the following "CNT"), use two electrodes between which ions can migrate. In the known actuator concepts, one of the electrodes consists of CNTs. The elongation of the CNTs caused by the migrating ions then produces the change in length and force development of the actuator. The other, not necessarily formed with the CNTs electrode is indeed present with their mass in the actuator. However, this electrode contributes neither to the rigidity nor to the actuation of the actuator, cf. DE 102 44 312 A1 ,

In contrast, according to the invention, not all interposed nanotubes between two force transmission elements are electrically applied in the same sense, ie assigned to the same electrode. Rather, a subset of the nanotubes forms a first group and another subset of the nanotubes forms a second group. The nanotubes of the two groups are opposed to each other, so different electrodes assigned and acted upon with different polarities.

• – Während gemäß dem Stand der Technik eine Elektrode nur elektrisch genutzt wird und zur Masse beiträgt, ohne die Steifigkeit des Aktuators und die Aktuation des Aktuators zu beeinflussen, sind erfindungsgemäß die mit den Nanotubes der beiden Gruppen gebildeten Elektroden multifunktional, indem diese einerseits elektrisch als Elektroden genutzt werden, aber gleichzeitig auch zur Steifigkeit des Aktuators beitragen und die Aktuation des Aktuators beeinflussen. Durch die multifunktionale Nutzung der Elektroden kann der Bauaufwand verringert und die Masse des Aktuators verringert werden, die Aktuation des Aktuators verbessert werden sowie die Steifigkeit des Aktuators erhöht werden.
• – In DE 102 44 312 A1 ist beschrieben, dass sich je nach Polarität der elektrischen Beaufschlagung von Nanotubes eine unterschiedliche Amplitude der Aktuation der Nanotubes ergeben kann. Bilden die Nanotubes in einem Aktuator gemäß dem Stand der Technik lediglich eine Elektrode, so führt dies dazu, dass das Aktuationsverhalten des Aktuators von der Polarität abhängig ist. Durch den erfindungsgemäßen Einsatz mechanisch parallel zueinander geschalteter Nanotubes der beiden Gruppen ergibt sich auch bei Annahme der in DE 102 44 312 A1 beschriebenen Abhängigkeit des Aktuationsverhaltens der Nanotubes von der Polarität eine verringerte Abhängigkeit oder sogar Unabhängigkeit der Amplitude der Aktuation des erfindungsgemäßen Aktuators von der Polarität der elektrischen Beaufschlagung. Grund hierfür ist, dass zwar die Amplitude der Aktuation der Nanotubes in den einzelnen Gruppen unterschiedlich sein kann. Das Gesamtverhalten der beiden Gruppen ”mittelt” aber die unterschiedlichen Amplituden der Aktuationen der Nanotubes heraus, so dass die Gesamtaktuation des Aktuators von der Polarität der elektrischen Beaufschlagung unabhängig ist oder zumindest eine Abhängigkeit von der Polarität verringert ist.
• – Für aus dem Stand der Technik bekannte Stapelaktuatoren sind die Elektroden räumlich isolierend voneinander zu trennen. Der Einsatz des erforderlichen Isolators hat zur Folge, dass sich ein vergrößerter Abstand zwischen den Elektroden ergibt. Dieser erhöhte Abstand zwischen den Elektroden erhöht aber den Elektrolytwiderstand. Die Zeitkonstante des elektrischen Systems ist proportional zu dem Elektrolytwiderstand, was zur Folge hat, dass für derartige Stapelaktuatoren der Aktuator langsamer auf die elektrische Beaufschlagung anspricht. Erfindungsgemäß kann der Einsatz eines zusätzlichen Isolators entbehrlich sein, wodurch der Bauaufwand verringert wird, eine kompakte Gestaltung ermöglicht ist, das Gewicht verringert werden kann und ein schneller Aktuator mit einer kleinen Zeitkonstante des elektrischen Systems bereitgestellt werden kann.

Furthermore, according to the invention, the nanotubes of the two groups are not connected in series in individual actuator packages in a mechanical series connection. Rather, the nanotubes of the groups are interposed in mechanical parallel connection between the power transmission elements. This embodiment of the invention has the following exemplary, non-limiting and non-limiting advantages of the invention:

• - While according to the prior art, an electrode is only used electrically and contributes to the mass, without affecting the rigidity of the actuator and the actuation of the actuator, the electrodes formed with the nanotubes of the two groups are multifunctional according to the invention, on the one hand electrically as electrodes but at the same time also contribute to the stiffness of the actuator and influence the actuation of the actuator. By the multifunctional use of the electrodes, the construction cost can be reduced and the mass of the actuator can be reduced, the actuation of the actuator can be improved and the rigidity of the actuator can be increased.
• - In DE 102 44 312 A1 It is described that, depending on the polarity of the electrical application of nanotubes, a different amplitude of the actuation of the nanotubes can result. Form the nanotubes in an actuator according to the prior art, only one electrode, this leads to the fact that the Aktuationsverhalten of the actuator is dependent on the polarity. The use according to the invention of mechanically connected mutually parallel nanotubes of the two groups also results, assuming the in DE 102 44 312 A1 described dependence of the Aktuationsverhaltens the nanotube of the polarity a reduced dependence or even independence of the amplitude of the actuation of the actuator according to the invention of the polarity of the electrical impingement. The reason for this is that, although the amplitude of the actuation of the nanotubes in the individual groups may be different. However, the overall behavior of the two groups "mediates" the different amplitudes of the actuations of the nanotubes, so that the overall actuation of the actuator is independent of the polarity of the electrical application or at least a dependence on the polarity is reduced.
• - For known from the prior art Stapelaktuatoren the electrodes are spatially insulating separate from each other. The use of the required insulator results in an increased distance between the electrodes. However, this increased distance between the electrodes increases the electrolyte resistance. The time constant of the electrical system is proportional to the electrolyte resistance, with the result that for such stack actuators, the actuator responds more slowly to the electrical impingement. According to the invention, the use of an additional insulator can be dispensed with, whereby the construction cost is reduced, a compact design is made possible, the weight can be reduced and a fast actuator with a small time constant of the electrical system can be provided.

It is entirely possible that in the actuator only two power transmission elements with nanotubes of the two groups in mechanical parallel connection, but different electrical impingement find use. If an enlarged Aktuation of the actuator, so enlarged adjustment paths or increased actuating forces are brought about, can be carried out according to a further embodiment of the invention in an actuator, a mechanical series connection of series-connected pairs of power transmission elements with interposed nanotubes of the first and second group. In this case, it is also possible for adjoining force transmission elements of adjacent pairs to be formed as a common integral force transmission element.

• – der gewünschten Bauform,
• – dem gewünschten Aktuatorkonzept,
• – der gewünschten Geometrie,
• – den herbeiführbaren Wirkrichtungen, also beispielsweise einer Verschiebung oder Verschwenkung des Aktuators mit seiner elektrischen Beaufschlagung,

können beliebige Geometrien der Kraftübertragungselemente und Ausrichtungen der Nanotubes zueinander und zu den Kraftübertragungselementen Einsatz finden. Gemäß einer erfindungsgemäßen Ausgestaltung eines Aktuators sind die Kraftübertragungselemente als ebene Platten ausgebildet. Die Wirkrichtung sowie Vorzugsrichtung der Nanotubes ist hierbei quer zur Erstreckungsebene der Platten orientiert. Beispielsweise kann – vereinfacht gesagt – auf diese Weise eine Art ”Aktuatorzelle” mit den ebenen Platten und dazwischen angeordneten Nanotubes ausgebildet werden, welche in erster Näherung quaderförmig sein kann.Depending on

• - the desired design,
• The desired actuator concept,
• The desired geometry,
• The action that can be brought about, that is, for example, a displacement or pivoting of the actuator with its electrical impingement,

Any geometry of the power transmission elements and orientations of the nanotubes to each other and to the power transmission elements can be used. According to an embodiment of an actuator according to the invention, the force transmission elements are designed as flat plates. The effective direction and preferred direction of the nanotube is oriented here transversely to the plane of extension of the plates. For example, in simple terms, a kind of "actuator cell" can be formed with the planar plates and nanotubes arranged therebetween, which in a first approximation can be cuboidal.

In principle, the distribution of the nanotubes of the two groups can be arbitrary. Conceivable here is a random arrangement of the nanotubes of the individual groups or a regular arrangement. In a further embodiment of the invention, however, nanotubes of the two groups are each arranged such that nanotubes of each group are arranged adjacent to one another in one Type bundles without being arranged between these nanotubes of a bundle of nanotubes of the other group. This can be advantageous for the preparation of the groups of nanotubes by bundling them and bundling the connection of the nanotubes of this group to the electrical contacting and the worktops.

Alternatively or additionally, it is possible for the nanotubes-seen in a cross section to the longitudinal axis of the nanotubes-to be arranged in a kind of area or field. The bundles, areas or fields of the nanotubes of the two groups are then arranged side by side transversely to the effective direction, wherein the length of the electrical paths between the electrodes formed by the nanotubes of the two groups is predetermined by the distance of the bundles, areas or fields and thus ultimately the time constant of the actuator can be influenced.

A further embodiment of the invention is based on the finding that it would be particularly advantageous for a rapidly responding actuator if ideally one nanotube of one group would always be arranged closely adjacent to a nanotube of the other group, whereby the electrical paths through the electrolyte could be minimized , The invention proposes that the fields of the two groups are each formed strip-shaped. In extreme cases, the strip would have the width of the cross section of the nanotube so that the nanotubes of a strip form a row. It is entirely possible that in practice the strips are widened formed with several juxtaposed nanotubes of the same group. Here, the nanotubes can be arranged in a strip in ordered rows or distributed randomly in the strip. The strips of the nanotubes of the two groups are then arranged next to each other, wherein the distance of the strips from one another determines the length of the passageway between the individual electrodes through the electrolyte. The length of the stripes then correlates with the number of nanotubes, for which there is then a minimized distance to an adjacent nanotube of one stripe of the other group of nanotubes. The strips can have constant or variable width and any length. While it is quite possible that the strips have any curved, curved or circular segment-shaped longitudinal axis, the longitudinal axis of the strips is at least partially rectilinear for an embodiment of the invention.

In a further embodiment of the invention, it is proposed that the fields or strips are nested one inside the other. As a simple example, the fields or stripes may form a kind of concentric circles or rings. Quite possible, however, that the fields or strips also have any other nested contours, for example, are rectangularly nested o. Ä.

It is also possible that the fields or strips are each formed with a kind of finger. Here, the longitudinal axes of the fingers may be straight or curved and / or the width of the fields or strips may be constant or vary. According to this embodiment, the fingers of one group are arranged in spaces which result between fingers of the other group, whereby a compact construction can result with a small time constant for a fast response of the actuator.

The contacting of the nanotube with the associated contact elements for the electrical application of the same can be done arbitrarily according to the prior art. For an embodiment according to the invention, the nanotubes of one or both groups are contacted on one side and / or on the end. For an end-side contacting, the contact element can be supported directly on the force transmission element. Particularly advantageous here is an embodiment in which the force transmission element is designed as a structural unit or integrally with the contact element.

Advantageous developments of the invention will become apparent from the claims, the description and the drawings. The advantages of features and of combinations of several features mentioned in the introduction to the description are merely exemplary and can come into effect alternatively or cumulatively, without the advantages having to be achieved by embodiments according to the invention. Further features are the drawings - in particular the illustrated geometries and the relative dimensions of several components to each other and their relative arrangement and operative connection - refer. The combination of features of different embodiments of the invention or of features of different claims is also possible deviating from the chosen relationships of the claims and is hereby stimulated. This also applies to those features which are shown in separate drawings or are mentioned in their description. These features can also be combined with features of different claims. Likewise, in the claims listed features for further embodiments of the invention can be omitted.

BRIEF DESCRIPTION OF THE FIGURES

In the following the invention will be further explained and described with reference to preferred embodiments shown in the figures.

1 shows a schematic side view of an actuator according to the invention.

2 shows a schematic plan view of a contact element of another actuator according to the invention.

3 shows a schematic plan view of another contact element of another actuator according to the invention.

DESCRIPTION OF THE FIGURES

1 shows schematically in a side view an actuator 1 which forces 2 is exposed or forces 2 generated in the direction of a direction of action 3 are oriented in 1 is vertically oriented. The actuator 1 is with power transmission elements 4 . 5 formed, in which it is in accordance with the illustrated embodiment 1 plane, transverse to the direction of action 3 oriented plates 6 . 7 is. About the power transmission elements 4 . 5 can connect to the environment of the actuator 1 and / or adjacent components. It is also possible that the power transmission elements 4 . 5 only a partial actuator 1 limit and be in operative connection with another corresponding or deviating further part-actuator.

Between the power transmission elements 4 . 5 groups extend 8th . 9 each with a group 8th . 9 associated nanotubes 10-1 . 10-2 . 10-3 , ... such as 11-1 . 11-2 , 11-3 , ... The nanotubes 10 . 11 have an orientation in a preferred direction, which parallel to the direction of action 3 is oriented. In the schematic representation according to 1 are the nanotubes 10 . 11 exactly parallel to the effective direction 3 oriented. Also included is an embodiment in which the orientation of the nanotube 10 . 11 stochastic against the parallel orientation to the direction of action 3 fluctuates, cf. For this example, the information on the preferred directions of Nanotubes in DE 10244312 A1 , Furthermore, in 1 the nanotubes 10 . 11 shown schematically as individual elements. So-called "bucky-paper" may also be used, provided that the nanotubes contained herein 10 . 11 a preferred orientation in the direction of the preferred direction parallel to the direction of action 3 have.

In one end region are the nanotubes 10 electrically with a contact element 12 connected. The nanotubes are corresponding 11 with a contact element 13 electrically connected. The contact elements 12 . 13 are acted upon by an electrical supply, not shown, with the same electrical amplitude, but opposite electrically, so acted upon with different polarity. The nanotubes 10 . 11 extend into an electrolyte in which these electrodes 14 . 15 form different polarity.

Basically, any connection possibilities between the nanotubes 10 . 11 in the area of their end faces with the power transmission elements 4 . 5 and / or the contact elements 12 . 13 possible. For example, the end faces can rest loosely on said elements, which can be done under a bias, which by the forces 2 can be generated or by additional elastically biased biasing elements between the power transmission elements 4 . 5 can act. It is also possible that a positive connection between the nanotubes 10 . 11 and the said elements 4 . 5 . 12 . 13 he follows. Furthermore possible is the cohesive fastening, connection and / or contacting. It is also possible that a contact element 12 . 13 consists of a conductor material which is chemically and locally limited at the point of contact with the nanotubes 10 . 11 can be converted to a carbide area, which then the cohesive and thus stable mechanical and electrical connection between the nanotubes 10 . 11 and the contact elements 12 . 13 serves.

In the in 1 illustrated schematic embodiment forms the right half of the power transmission elements 4 . 5 , the contact element 13 and the nanotubes 11 the group 9 a partial actuator 16 while a corresponding part actuator 17 in opposite polarity with the left half of the power transmission elements 4 . 5 , the contact element 12 and the nanotube 10 the group 8th is formed. The part actuators 16 . 17 are connected together in mechanical parallel connection by said halves of the plates 6 . 7 rigidly connected to each other, which is according to the embodiment 1 by integral formation of the two halves in the plates 6 . 7 he follows. Quite conceivable is that the part actuators 16 . 17 initially manufactured separately and then a fixed connection of the associated power transmission elements of the part actuators 16 . 17 to form the entire actuator 1 he follows. Quite possible is that in an actuator 1 more than two part actuators 16 . 17 forming components are used in a cross section transverse to the direction of action 3 - 3 through the nanotubes 10 . 11 form nanotubes of groups 8th . 9 each formed separately from each other Fields or areas 18 . 19 in which only nanotubes 10 respectively. 11 a single group 8th respectively. 9 are arranged without being within these fields or areas 18 . 19 nanotubes 11 . 10 the other group 9 respectively. 8th are located. Within the fields 18 . 19 are the nanotubes 10 . 11 with largely parallel orientation in the manner of bundles 20 . 21 arranged.

In plan view in the direction of the effective direction 3 are the contact elements 12 . 13 each also flat. Just a simple one. To name an example, the contact elements 12 . 13 with square plates 6 . 7 be formed rectangular, wherein the longer side of the rectangle approximately the length of the side length of the plates 6 . 7 while the shorter side of the rectangle is slightly smaller than half the side length of the square plates 6 . 7 ,

2 and 3 show further embodiments of the design of the contact elements 12 . 13 and the distribution of nanotubes 10 . 11 of the groups 8th . 9 as well as the education of the fields 18 . 19 as well as bundles 20 . 21 :

According to 2 are the contact elements 12 . 13 each with circular strips 22a . 22b such as 23a . 23b formed, which via a common line 24 . 25 can be acted upon with opposite polarity. The respective stripes 22 . 23 are arranged under electrical isolation against each other as closely as possible adjacent to each other. For the embodiment according to 2 are the stripes 22 . 23 annularly formed with the same ring thickness and nested concentrically with each other. Radial inwards thus change stripes 22a . 23a . 22b . 23b with different polarity.

For the embodiment according to 3 extend from the ladders 24 . 25 parallel stripes 22 . 23 which have constant width and straight longitudinal axes. The Stripes 22 . 23 each form a kind of finger 26 . 27 , The finger 26 , which is perpendicular to the plane oriented Nanotubes 10 the group 8th wear, extending in spaces between the fingers 27 , which is perpendicular to the plane oriented Nanotubes 11 the group 9 Wear, being between the fingers 26 . 27 results in a remaining distance or gap, which avoids an electrical short circuit.

In the embodiments according to 2 and 3 are the nanotubes 10 . 11 and thus the load / effective directions each vertical to the drawing plane 2 oriented. With the stripes 22 . 23 are each ends of the nanotubes 10 . 11 of the groups 8th . 9 contacted or the stripes 22 . 23 additionally carry the nanotubes 10 . 11 ,

According to 1 are the contact elements 12 . 13 separate from the power transmission elements 4 . 5 educated. Alternatively, the power transmission elements 4 . 5 and contact elements 12 . 13 form a structural unit or be designed as an integral component. For the illustrated embodiment, both contact elements 12 . 13 a power transmission element 5 assigned. Quite possible, however, in a modification that a contact element 12 a power transmission element 4 is assigned while the other contact element 13 the other power transmission element 5 assigned. This also applies to the in the 2 and 3 illustrated configurations, so that the stripes 22 with associated conductor 24 the power transmission element 4 are assigned while the other strips 23 with associated conductor 25 the other power transmission element 5 assigned.

• – in der Automobilindustrie,
• – in der Elektro- und Halbleiterindustrie,
• – im Maschinenbau,
• – in der Chemieindustrie,
• – in der Energietechnik,
• – in der Medizintechnik,
• – in der Luftfahrt,
• – in der Raumfahrt,
• – in der Verkehrstechnik,
• – in der Mechatronik oder Adaptronik,

um nur einige Beispiele zu nennen.The actuator according to the invention can be used, for example

• - in the automotive industry,
• - in the electrical and semiconductor industry,
• - in mechanical engineering,
• - in the chemical industry,
• - in energy technology,
• - in medical technology,
• - in aviation,
• - in space travel,
• - in traffic engineering,
• - in mechatronics or adaptronics,

to name just a few examples.

The orientation of the nanotube 10 . 11 in a bucky paper, for example, can be prepared by alignment of the nanotubes 10 . 11 be done by physical or chemical methods. For example, the nanotubes 10 . 11 be aligned by an electric, magnetic and / or electromagnetic field and / or under the influence of ultrasound in a surfactant suspension. The sedimentation carried out under these conditions or transfer to a suitable substrate, in accordance with the Langmuir-Blodgett technique, can produce a higher degree of alignment. It is also possible to align the nanotube by a rotational method in which the nanotubes are aligned in parallel in a suspension substantially along their longitudinal axis and the aligned nanotube layer is then skimmed off or transferred to a support and dried. Indications of electrolytes to be used and concentrations to be used as well as measures for increasing the actuation amplitude of the nanotubes 10 . 11 for example DE 102 44 312 A1 be removed.

For the contact elements 12 . 13 can use any electrically conductive materials, in particular precious metals such as silver, gold, platinum, copper or aluminum, electrically conductive polymers, etc. The contact elements can with the nanotubes 10 . 11 be glued or rolled on a bucky paper. It is also possible that an electrically conductive layer by means of sputtering, CVD or PVD process or spincoating with the nanotubes 10 . 11 or the Bucky paper is connected. Also possible is that the bucky paper or the nanotubes 10 . 11 directly on the contact element 12 . 13 grow and be produced. It is possible that the contact elements 12 . 13 are formed porous. It is also possible to design the contact elements 12 . 13 in the form of webs with a conductor material formed from a carbide or titanium or silicon.

LIST OF REFERENCE NUMBERS

1

actuator

2

force

3

effective direction

4

Power transmission element

5

Power transmission element

6

plate

7

plate

8th

group

9

group

10

nanotube

11

nanotube

12

contact element

13

contact element

14

electrode

15

electrode

16

Part of actuator

17

Part of actuator

18

field

19

field

20

bunch

21

bunch

22

strip

23

strip

24

ladder

25

ladder

26

finger

27

finger

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10244312 A1 [0006, 0006, 0013, 0015, 0015, 0030, 0041]
• WO 2000/050771 [0007]
• DE 102004025603 A1 [0008]
• WO 03/061107 A2 [0009]
• DE 102005034323 A1 [0010]

Cited non-patent literature

• Gao, M .; Dai, L .; Baughman, RH; Spinks, GM; Wallace, GG: Electrochemical properties of aligned nanotube arrays: basis of new electromechanical actuators; Proc. of SPIE, Vol. 3987, Electroactive Polymer Actuators and Devices (EAPAD), ed. Y. Bar-Cohen (March 2000) [0003]
• Shaoming, Huang, Liming Dai, Albert WH Mau, J. Phys. Chem. B 1999, 103, 4223 [0003]
• HP Monner, S. Mühle, P. Wierach, J. Riemenschneider: Carbon Nanotubes - a Multifunctional Lightweight Material for Adaptronics, Adaptronic Congress 2003, 01.-03. April 2003 [0004]
• J. Riemenschneider, T. Mahrholz, J. Mosch, HP Monner, J. Melcher: Carbon Nanotubes - Smart Materials of the Future: Experimental Investigation of the System Response; II Eccoma's Thematic Conference on Smart Structures and Materials CA; Mota Soares et al. (Eds.), Lisbon, Portugal, 18.-21. 07. 2005 [0004]
• Fukuda T. et al .: Perspective of Nanotube Sensors and Nanotube Actuators. In: 4th IEEE Conference on Nanotechnology, 2004, pp. 41-44 [0009]

Claims (8)

Actuator ( 1 ) with two power transmission elements ( 4 . 5 ), in which a first group ( 8th ) and a second group ( 9 ) Nanotubes ( 10 . 11 ) is supported, which are electrically acted upon and thus deformable and in a direction of action ( 3 ) are given preferential direction, characterized in that a) the nanotubes ( 10 ) of the first group ( 8th ) opposite to the nanotubes ( 11 ) of the second group ( 9 ) and b) the nanotubes ( 10 ) of the first group ( 8th ) and the nanotubes ( 11 ) of the second group ( 9 ) in mechanical parallel connection between the force transmission elements ( 4 . 5 ) are interposed. Actuator ( 1 ) according to claim 1, characterized in that a plurality of pairs of power transmission elements connected in series in series ( 4 . 5 ) with nanotubes ( 10 . 11 ) of the first and second groups ( 8th . 9 ) are provided. Actuator ( 1 ) according to one of the preceding claims, characterized in that the force transmission elements ( 4 . 5 ) as flat plates ( 6 . 7 ) are formed and the effective direction ( 3 ) and the preferred direction of the nanotubes ( 10 . 11 ) transverse to the plane of extension of the plates ( 6 . 7 ) are oriented. Actuator ( 1 ) according to one of the preceding claims, characterized in that nanotubes ( 10 ) of the first group ( 8th ) in a bundle ( 20 ) or in a cross section in a field ( 18 ) and nanotubes ( 11 ) of the second group ( 9 ) in a bundle ( 21 ) or in a cross section in a field ( 19 ) and the two bundles ( 20 . 21 ) or fields ( 18 . 19 ) of nanotubes ( 10 . 11 ) of the two groups ( 8th . 9 ) when viewed transversely to the direction of action ( 3 - 3 ) are arranged side by side. Actuator ( 1 ) according to one of the preceding claims, characterized in that the fields ( 18 . 19 ) of the two groups ( 8th . 9 ) each in adjacent strips ( 22 . 23 ) are arranged. Actuator ( 1 ) according to claim 4 or 5, characterized in that the fields ( 18 . 19 ) or stripes ( 22 . 23 ) are nested inside each other. Actuator ( 1 ) according to claim 4 or 5, characterized in that the fields ( 18 . 19 ) or stripes ( 22 . 23 ) each with fingers ( 26 . 27 ) and fingers ( 26 ) of a group ( 8th ) in spaces between fingers ( 27 ) of the other group ( 9 ) are arranged. Actuator ( 1 ) according to any one of the preceding claims, characterized in that the nanotubes ( 10 . 11 ) of the two groups ( 8th . 9 ) on one side and / or end by opposite to each other electronically acted upon contact elements ( 12 . 13 ) are contacted.

Images