WO2013176585A1

WO2013176585A1 - A method and a device for assembling a composite structure

Info

Publication number: WO2013176585A1
Application number: PCT/SE2012/000083
Authority: WO
Inventors: Dmitry SUYATIN; Lars Montelius; Sergey Shleev; Richard SUNDBERG
Original assignee: Suyatin Dmitry; Lars Montelius; Sergey Shleev; Sundberg Richard
Priority date: 2012-05-24
Filing date: 2012-05-24
Publication date: 2013-11-28
Also published as: WO2013176585A8

Abstract

A method and device for assembling a composite structure comprising nano-components. The component is moved in space by a manipulator from a manufacturing position to an assembly position and attached in place and functionally coupled to the functionality of the structure at the mounting position. In addition the component may be processed in order to make the assembled parts suitable for further assembly steps and/or make the assembled components suitable for operation. The component comprises a lug for engagement of the manipulator. The component is covered by a protective structure over at least some portions and the protective structure is removed after assembly, completely or partly. This method allows different components and nanostructures made with otherwise incompatible technologies to be coupled to each other to form three- dimensional devices being able to perform more complex functions.

Description

TITLE: A METHOD AND A DEVICE FOR ASSEMBLING A COMPOSITE STRUCTURE

FIELD OF INVENTION

The present invention relates to a method and a device for assembling a composite structure in macro-, micro- and nano-scale using manipulators for moving a component to a mounting position.

BACKGROUND

There is a growing interest in nanostructure-based devices. Such devices and their applications can be useful in many different fields ranging from electronics to bio-devices. The main

characteristic of such devices is that they contain nanostructures that give the device its specific functionality.

Such nano-devices may need to incorporate components made with different technologies, which cannot easily be manufactured at the same physical position or cannot be manufactured at the same time. Thus, there is need to assemble nano-components, which may have different

functionality, into a composite structure, which may be in the nano-scale or the micro-scale or the macro-scale.

WO 2010/123570 A2 discloses a method for producing a three-dimensional feature, comprising: (a) providing a nano-manipulator device; (b) positioning an article with the nano- manipulator device; and (c) manipulating the article to produce the three-dimensional (3D) feature.

However, the technology disclosed in the prior art publications still have deficits that need to be addressed. One concern is how the manipulator is arranged to engage the article and transport the article without destroying its functionality. Other deficiencies with the current technology are discussed in more details below.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to mitigate, alleviate or eliminate one or more of the above-identified deficiencies and disadvantages singly or in any combination.

In an aspect, there is provided a method of assembling a composite structure comprising components, at least some of which are smaller than about 50 μη , comprising steps in any sequence: providing a component at an attachment position; coupling a manipulator to the component; separating the component from its attachment position; moving the component by the manipulator in to a mounting position; attaching the component to a mounting structure at the mounting position; decoupling the manipulator from the component; characterized by at least partially covering the component by a protective structure.

In embodiments, the method may further comprise at least one of the following method steps: providing means for the component protection during the structure assembly; encapsulating the component to protect the component functionality and providing means for prompt and reliable component reallocation and functional connection; coupling the component functionality to the functionality of the structure at the mounting position; component processing in order to make the assembled parts suitable for further assembly steps; and component post-processing in order to make the assembled component suitable for operation.

The protective structure or layer may be arranged for preserving critical parts of the component during subsequent processing and handling, such as detachment, manipulation, placement, functional connection and operation. The protective structure may be a thin film coating or a sheet of material, such as a metal plate, which may stay in place or be removed after the detachment step. The covering step may be performed by deposition of a metallic layer to at least a part of the component, or wherein the covering step is performed by applying a protective structure by the method steps as mentioned above. The covering step may be performed during a manufacture of the component, either directly after the manufacturing of the component or as an integral part of the manufacturing of the component. The component may comprise a lug having no functionality, further comprising coupling the manipulator to the lug of the component and separating the component from the manipulator by decoupling the manipulator from the lug or removing the lug or part of the lug.

In another embodiment, the method may be used in order to repair structures by replacing faulty structures with new structures.

In a further embodiment, the method may be used in order to build complicated structures that later can be employed as a stamp in a replicating technology, such as nano-imprint lithography.

The method may further be used in order to fabricate device for in vivo and ex vivo applications.

The method may further be used in order to fabricate self-powered devices.

The method may further be used in order to fabricate wireless devices.

In another aspect, there is provided a for assembling a composite structure comprising components, at least some of which are smaller than about 50 μιη, the device comprising: a component arranged at an attachment position; a manipulator, which may be coupled to the component for separating the component from its attachment position and which can move the component to a mounting position for attachment of the component to a mounting structure at the mounting position; a means for decoupling the component from the manipulator at the mounting position; characterized by a protective structure, which at least partly covers the component.

In embodiments, the device may further comprise at least one of the following: means for the component protection during the structure assembly; means for the component processing enabling the component encapsulation for the component protection and prompt and reliable component reallocation, fixation and coupling to the structure at the mounting position; means for the component processing enabling the component attachment to a mounting structure at the mounting position; means for the component processing enabling coupling of the component functionality to the functionality of the structure at the mounting position; means for the component processing in order to make the assembled parts suitable for further assembly steps; means for the component post-processing in order to make the assembled component suitable for operation.

In another embodiment, the protective structure may be a thin film coating or a sheet of material, such as a metallic layer. The film coating or sheet of material may be at least partly removed. The component may be provided with a lug, which forms a coupling arrangement for the manipulator, and which may be removed or left intact after assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects, features and advantages of the invention will become apparent from the following detailed description of embodiments of the invention with reference to the drawings, in which:

Fig. 1 is a is a schematic view comparing the present invention with Lego building blocks.

Fig. 2 is a schematic view showing the manufacturing of a gold sheet for use in the method according to embodiments of the invention.

Fig. 3 is a schematic view showing handling of the gold sheet according to Fig. 2.

Fig. 4 is a schematic view from the top showing the gold sheet arranged at four electrodes.

Fig. 5 is a schematic view similar to Fig. 4 and shows a set-up for testing contact resistance.

Fig. 6 is a schematic perspective view comprising a pillar with components.

Fig. 7 is a view similar to Fig. 6 in which part of the pillar has been moved.

Fig. 8 is four photographs of a pillar as shown in Fig. 6 and shows how the pillar is provided with a protecting metallic layer.

Fig. 9 is three photographs showing the upper portion of the pillar after movement to an assembly position. DETAILED DESCRIPTION OF EMBODIMENTS

Below, several embodiments of the invention will be described. These embodiments are described in illustrating purpose in order to enable a skilled person to carry out the invention and to disclose the best mode. However, such embodiments do not limit the scope of the invention.

Moreover, certain combinations of features are shown and discussed. However, other combinations of the different features are possible within the scope of the invention.

A method of assembling a composite structure comprising components, at least some of which are smaller than about 50 μηι, from here on referred to as nanoLego Blocks, for prompt and reliable detachment, manipulation and assembly of pre-fabricated and discrete functional macro-, micro- and nanostructure based components into higher-order functional complex 3D devices is described.

In the first step, a discrete nanostructure having a certain function or ability is fabricated using a desired technology, which is suitable for this particular device. Then, in a second step, this device is encapsulated in a special way to form a nanoLego Block so that the device functionality can be protected while providing means for prompt and reliable device detachment, manipulation and functional assembly, by e.g. a nanomanipulator, and placing it on a certain location in a three dimensional assembly. In this way the different devices and nanostructures made with otherwise incompatible technologies may be coupled to each other to form 3D devices being able to perform more complex functions. In a final step, some post-processing treatment after the nanoLego Blocks assembly can also be performed making the assembled component suitable for further assembly steps and for operation.

Embodiments of the present invention relates generally to nano-scale lithography, and more particularly to a generic serial assembly technology, being able to integrate several differently fabricated macro-, micro- and nanostructures, using various kinds of nanotechnologies, into a functional device being employable in various application fields.

Fig. (1): The pictures compare the basic assembly of Lego blocks 10 ((a)-(b)) to that of the assembly of an imaginative complex device out of nanoLego Blocks ((c)-(d)). The imaginative device assembly illustrates embodiments of the invention: nanoLego Blocks with different functionality, e.g. sensing component 11 with nano wire-based sensing elements (the small vertical lines looking like hair close to the apex of the triangle), an amplification unit 12 (the tree-terminal central structure), a nano wire-based LED 13 (nLED), two electrodes 14 of a fuel cell and some interconnecting wires 15 are separately fabricated for this subsequent assembly in a complex 3D functional device with designed properties.

Fig. (2) shows the pre-processing for a gold nanoLego Block 24. 1. Polished GaP substrate 21 is cleaned in acetone, isopropanol (IP A) and dried with nitrogen gas.

2. Spin-coating of 950 KDa polymethylmethacrylate (PMMA) layer 22 at 2000 revolutions per minute (rpm).

3. Soft baking on a hotplate at 160 °C for 15 min.

4. Additional PMMA layer 23 spun at 2000 rpm.

5. Soft baking on a hotplate at 160 °C for 15 min.

6. Thermal evaporation of about 1 μιη thick gold layer 24.

7. Dissolving the underlying polymer leaving some small residues 25 as shown.

Fig. (3) shows a picture of a gold nanoLego Block 31 which has been cut out from and separated from the main gold layer 24, in an angle view, (b) The top view of the same nanoLego Block with all relevant dimensions. The shaded are is a hole 32 having the dimensions shown in Fig. 3.

Fig. (4): A completed reallocation to a desired new location with a functional connection to its new place (transplantation) for the gold nanoLego Block 31 , top view. The nanoLego Block was transplanted to a set of metal electrodes 46, 47, 48, 49 for contact resistance measurements. The letters there denote the probes for the contact resistance measurements with four-terminal contact resistance method: Vi and V₂ are the potential probes, Ij_n and I_out are the current terminals. The gold nanoLego Block 31 has been cut at the left side to remove the manipulator 33, as is shown in Fig. 3. The gold nanoLego Block 31 has been immobilized by four dots 42, 43, 44, 45 of tungsten (W) after having had the Block 31 firmly pressed against the electrodes. A further tungsten dot 41 attaches the gold sheet 31 to the outer end of the electrode 47 via the opening 32. Two deep cuts 36 and 37 are cut through the electrodes and the gold sheet in order to form an isolated area.

Fig. (5): The contact configuration for the four-terminal contact resistance measurements as it was used for the transplanted gold nanoLego Block. Current flow is indicated by the dotted arrow 51. The voltage sensing paths are indicated by the double-dashed arrows 52. The thick black lines are the mentioned cuts 36, 37 made with ion beam. The circular area 53 indicates the contact area where the contact resistance measurements were performed. The dashed lines show the location of the micro electrodes 46, 47, 48, 49 under the gold nanoLego Block.

Fig. (6): Pictures of: (a) the micromanipulator probe 33, see Fig. 3, positioned on a side of a pillar 61 with nLEDs, and (b) the probe 33 fused to the pillar with nLEDs by a small tungsten deposition 62, the final separating cut 63 was made by ion beam. Fig. (7): The pillar 61 with nLEDs placed to a new position and fastened to the surface of a micro electrode 71 with tungsten deposition 72 at one corner. In this image the probe 33 has already been separated from the sample.

Fig. (8): The pictures show NanoLego Blocks with nLEDs 81 prepared (a) without and ((b)- (d)) with metal shield protecting the nLED functionality, (a) The nLEDs were at least partily destroyed by the focused ion beam during the NanoLego Block fabrication process, (b) The gold NanoLego Block 31 being transferred on top of the nLEDs for the formation of metal protective shield 82. This shield protected the nLEDs during the focused ion beam processing in the course of the NanoLego Block fabrication, (c) The gold NanoLego Block placed on top of the nLEDs and fixated there with tungsten deposition 83, the micromanipulator was separated from the Block as shown at 84. (d) A new nLEDs-based NanoLego Block made with the help of another NanoLego Block (gold NanoLego Block) prepared for detachment and manipulation.

Fig. (9): The pictures of NanoLego Blocks with the metal shield protection, (a) A NanoLego Block reallocated to a new locus with the micromanipulator probe 33 still attached. The NanoLego Blocks can be positioned at any desired place on a three dimensional surface, (b) A cross section for a NanoLego Block with nanowires embeded after reallocation to a new locus. Note that the top part of the metal shield is covered with substantial amount of unwanted material which was

unintentionally deposited during the NanoLego Block fabrication process (the metal shield layer can be seen as a thin layer on top of the nanowires; the nanowires can be seen as vertical embedded pillars), (c) The removal of the metal protecting shield bu the manipulator opens the nanowires which were protected during the NanoLego Block manipulations.

There is a growing interest in nanostructure based devices. Such devices and their applications can be found in many different fields ranging from electronics to biodevices. The main characteristic of such devices is that they contain nanostructures that give the device a specific functionality. This functionality may be different depending on what type of nanostructure is employed. This is explored within the fields of nanotechnology and nanoscience. A common definition of

nanotechnology and nanoscience is the following:

One nanometer (one billionth of a meter) is a magical point on the dimensional scale.

Nanostructures are at the confluence of the smallest of human-made devices and the largest molecules of living things. Nanoscale science and engineering here refer to the fundamental understanding and resulting technological advances arising from the exploitation of new physical, chemical and biological properties of systems that are intermediate in size, between isolated atoms and molecules and bulk materials, where the transitional properties between the two limits can be controlled. One example of how nanotechnology may enhance current technology is in the field of electronics. Here the traditional transistor technology seems to be approaching its limit and nanotechnology might provide a solution employing innovative material combinations and nanowires.

The field of nanoscience is in nature widely interdisciplinary. Small devices are very attractive for many applications. For instance, at present there exist small biodevices, with characteristic sizes in the millimeters and centimeter range, but further scaling of the device size is very important since it may allow e.g. direct interactions with biological systems on cellular and sub cellular level, without causing extensive tissue damage and with minimal unwanted immune response. Integrated biodevices can be made to monitor the blood for specific substances or to administrate drugs in fixed time intervals. Some systems might combine the two and e.g. future implantable insulin pumps may be able to sense the blood glucose level and act accordingly by releasing insulin into the

bloodstream, thus acting as an artificial pancreas. However, these devices are rather large objects to be implanted into the body. There are considerably smaller implantable device as the so called Bionic Neuron (BION). Although much smaller than implantable insulin pumps, they are still big compared to cells and the implantation procedure may cause tissue damage and unwanted immune responses. Hence, to be less intrusive, the biodevices need to be scaled down further. It is however not only the challenge of making a device in a suitable scale which needs to be addressed before it can be realized. Issues like biocompatibility, propulsion and energy source also needs to be addressed. Hence, in order to be able to make a fully functional nano-device, one needs to integrate several ingredients of science and technology.

Typically the micro and nanodevices are nowadays realized with massively parallel lithographic techniques. The 3D-integration of circuits is considered as an attractive approach to stay on the semiconductor productivity roadmap at the same time providing such advantages as the intimate integration of disparate technologies. This 3D integration refers to a family of technologies enabling stacking of active layers with vertical connections and implies 3D manipulation with separate semiconductor pieces. Although this approach employs mechanical manipulations of single pieces the approach has been proven to be of significant industrial value and capable of large scale commercial production. This approach has been employed nowadays by all major semiconductor chip manufacturers. However, at present it is used only for the electronic circuit assembly to form a system-in-a-package and even though there is a clear trend in miniaturization of the single components used in the 3D assembly, the manipulations are presently done with pieces in sub- millimeter scale only. The standard techniques while allowing high volume and high speed massively parallel production are limited in the following: (1) they make very delicate structures on rather big substrates; (2) all technological steps employed for this need to be technologically compatible; (3) 3D structures are typically limited to the substrate surface and assembly of different crystals is limited typically to the millimeter range. The planar fabrication methods can be extended to some limited 3D capability only while suggested NanoLego concept serves as a real 3D assembly technique.

Processing at the nanoscale is important. But for a functional device, a certain nanostructure, allowing it to be used in real-time situations, has often to be connected to something that is somewhat larger in size. Various kinds of nanostructures may need to be integrated with each other in order to achieve certain functionality. However, different nanotechnologies for diverse nanostructures may not be compatible with each other, putting severe limitations for such integration since presently, when trying to fabricate functional complex self-contained nanobiodevices, we are facing the problem of the non-existence of an integrated fabrication and process technology allowing individual functional components and structures to be integrated with each other. The reason lies mainly in the fact that the different process technologies are incompatible with each other making a fully integrated fabrication technology impossible. Also, certain pre-processed structures - maybe in a macro-scale regime - may not be employed in the nanotechnology process. In pace with the development of nanotechnology, more and more advanced and dedicated fabrication processes are developed. In many cases these methods require a certain pre-condition, such as a clean structural surface. Hence, in many cases a processing pre-history of a certain element may hinder the employability for a given method. For instance, growing nanowires onto any given pre-structured surface can not be easily achieved. But, from a functional technological perspective, there is a need to be able to have nanowires being integrated onto such a pre-structured surface. One example is a nanoscaled neural probe where one would like to employ nanowires as needle electrodes being situated onto the very tip-end of an arrow-shaped structure, allowing an easy introduction into e.g. the brain-tissue.

Embodiments of the present invention circumvents such problems. The embodiments describes a design of nanoLego Blocks for prompt and reliable 3D assembly of macro-, micro- and nano-scaled components via detachment, manipulation and assembly of pre-fabricated and discrete functional macro-, micro- and nanostructure based components in a piece-by-piece approach into higher-order functional complex 3-dimensional circuits and devices. Hence, the nanoLego Blocks can be used for the future manufacturing of complex nanostructure based hierarchical devices. The assembly of a hypothetical device out of nanoLego Blocks is conceptually illustrated in Figure 1 where it is compared with the assembly of Lego-pieces. The imaginative device in the Figure 1 is composed of nanoLego Blocks with (i) a sensing functionality (the triangle), (ii) an amplification circuit (the tree-terminal central structure), (iii) nLEDs, (iv) two fuel cell electrodes, and (v) interconnecting wires. Hence, using the LEGO-type of building blocks with different functionality to form a complex device may pave the way for integrating functional elements forming totally new possibilities within various fields of science and technology.

Today it is possible to construct complex circuits where the individual components are in the nanometer scale. These circuits are however usually made on much large substrates and as a whole they thus become rather large. The described design of nanoLego Blocks differs from already current technology in that there is an absolute and precise position control of macro-, micro- and nano-components and allows integration of otherwise presently incompatible technologies like optical interconnects and data processing devices. The aim of this design is to utilize the possibility for direct 3D assembly of complex devices by combining discrete components with characteristic sizes in completely different scales.

Such complex devices can be found to be useful in many different applications. One such application is in electronics making it possible to integrate various functional structures into a higher-order device that could not be fabricated without utilizing an assembly process where individually processed structures are integrated. Another example is in biodevices where an assembled device as described above may be coated with a functional layer prohibiting various forms of immunological or any other biological reactions to occur when such a device is inserted into e.g. the body. A specific such device is a neural probe allowing measurements of neural activities in the neuronal system, e.g. neural signals from the brain. The characteristics of these devices are that they could not be fabricated by any other means since a technology that can process both micron-scaled and nano-scaled structures is not available. This means that embodiments of the invention provides a designer with means previously not existed. Another area of the nanoLego Blocks is to repair complicated and expensive structures by replacing a faulty structure with a new fully functional one. Another application area for the nanoLego Blocks is to build a complicated physical structure that later can be employed as a stamp in a replicating technology, such as nanoimpnnt lithography, that allows a 3D replication of such a complex physical structures in a step & print fashion.

To further illustrate and give some examples of the nanoLego Blocks we will below show the results for application of two different types of nanoLego Blocks: 1) gold nanoLego Blocks and 2) nLEDs nanoLego Blocks, the nLEDs being provided by QuNano AB. The gold nanoLego Blocks were about 50x50x1 μηι³ being directly cut from a 1 μπι thick sheet of gold, see Figures 2 and 3. The nLED nanoLego Blocks were about 10x10x10 μπι³, on which approximately 20 individual nLEDs were situated. The devices were transplanted, i.e. cut from their respective substrate of origin and then transferred to a new location and functionally connected there. This was achieved by using a Focused Ion Beam (FIB) and Scanning Electron Microscope (SEM) Dual Beam system (FIB-SEM), with integrated micromanipulator and gas injection instruments. The nanoLego Blocks differ from other elements in the sense that they allow for discrete functional components to be assembled one by one in real time. The nanoLego Blocks were transplanted onto gold micro contacts made with standard micro patterning techniques, see Figure 4. For the transplanted gold nanoLego Blocks the contact resistance, measured with a four-terminal contact resistance method was found to be less than 1 Ω, see Figure 5.

The first step towards making gold nanoLego Blocks was made by cutting out gold structures which could be placed on a set of electrodes for 4-point probe resistance measurements. The sample used for fabrication of the gold structures was a GaP substrate on which a 1 μπι thick film of gold was evaporated. To facilitate the lift-off of the structure, the gold was evaporated on a double layer of spin-coated PMMA 950 KDa resist. Each layer was spun at 2000 rpm. The first PMMA layer was soft-baked at 160 °C for 15 minutes before the second resist layer was applied. The same baking was done after the second PMMA layer deposition. The resist was removed in a warm (60 °C) acetone bath with subsequent washing in IPA and drying with nitrogen gas. Figure 2 illustrates this process.

The design of the gold nanoLego Blocks was done to facilitate its removal and positioning. Its exact appearance and measurements is shown in Figure 3. The nanoLego Blocks were shaped as square sheets with a smaller "jetty" area on one side. The jetty is the place where the probe is positioned in the separation process and it is the area of the dummy device which is removed after the transplantation completion.

When the nanoLego Block is put in contact with the designated place the nanoLego Block and the receiving area are fused together by a small tungsten deposition. When the deposition is completed and the nanoLego Block is firmly fastened to the position, the micromanipulator probe can be detached from the nanoLego Block by cutting off the jetty with the ion beam. The final processing step for the nanoLego Block transplantation is to perform two adequately deep cuts with the ion beam so that the structure is electrically divided into two separate pieces, see Figure 4. This was necessary for the contact resistance measurements with the four-terminal contact resistanc method. A completed nanoLego Block transplant is shown in Figures 4 and 5.

A further example of the nanoLego Blocks is the nLED-based nanoLego Block as displayed in Figures 6 and 7 showing its detachment, manipulation and assembly onto the new locus. Figure 8 presents pictures of NanoLego Blocks with nLEDs prepared (a) without and ((b)-(d)) with metal shield protecting the nLEDs. Form the Figure 1(a) it can be seen that the nLEDs without any protecting shield were affected during the NanoLego Block processing and were presumably partially melted and/ or sputtered. Figure l((b)-(d)) demonstrates that one nanoLego Block (gold nanoLego Block) may be used to construct another nanoLego Block (nLED nanoLego Block) with a better protection for the nanoLego Block functionality: the gold NanoLego Block in this case was transferred on top of the nLEDs for the formation of metal protective shield.

Figure 9 demonstrates the importance of the protective shield for the NanoLego Blocks functionality: the NanoLego Blocks can be positioned at any desired place on a three dimensional surface, however, as it can be seen in the cross section (Figure 9(b)), the NanoLego Blocks have a lot of material over deposited after their reallocation to a new locus. The removal of the metal protecting shield, as the final step, may open the functional components incorporated into the nanoLego Blocks and in this way enable their operation.

The results show clearly the ability to mill out a nanoLego Block with the FIB and, using the micromanipulator, position the nanoLego Block at an arbitrary location. The gold nanoLego Blocks are delicate to handle being relativity thin but the main reason for them being easier to separate than the nLED-based nanoLego Block. The gold layer from which the gold nanoLego Blocks were made sat only loosely on top of the GaP substrate so there were little contact between the nanoLego Block and the bulk of the substrate when performing the separation. In contrast, the nLED nanoLego Blocks on the other hand were very much in contact with the substrate being directly grown on its surface. The nLED nanoLego Block had to go through extensive milling before they could be properly separated.

Embodiments of the invention describes a design for nanoLego Blocks for prompt and reliable detachment, manipulation and assembly of pre-fabricated and discrete functional macro-, micro- and nanostructure based components into higher-order functional complex 3D devices and systems.

Embodiments of the invention addresses and solves the problems of making fully functional devices based on a multitude of nanostructured elements although they individually require to be fabricated separately. Such devices can be further processed using methods that will give certain functionalities or modalities to the complete device structure.

A building block for NanoLego-like assembly of complex devices: the building block is constructed in a special way to facilitate safe and easy building block detachment, manipulation, placement, functional connection and embodiment. For this the block may have a special protrusion ('jetty') to which manipulating probe can be attach or special holes for grippers or a specially designed magnetic lock or a special place facilitating vacuum tweezers connection. Importantly, the block has a special protection structure to preserve the critical parts, which will be performing the function in the assembled device, during the building block detachment, manipulation, placement, functional connection and embodiment. This protecting structure may be made of thin film coating or a sheet of material, e.g. metal plate, and may be removed or stay in place after the assembly process accomplishment. The building blocks also have an interface for communication with other blocks, which will typically consist of metal pads with a specific geometry or modification for better electrical contact. The interface may also consist of parts for optical, capacitive, magnetic, mechanical or chemical coupling. The metal pads for electrical connections may typically consist of a specific geometry which will enable key-lock mechanism for the block connection and / or a spring connection made of, e.g. , nanowire protrusions or sponge-like structure, for better compliance of non-planar surfaces.

The building blocks may be constructed out of other building blocks or, preferable, produced in highly parallel fashion with traditional lithographic and imprinting techniques. The prefabricated blocks may be either loosely or firmly connected to the original substrate. The building blocks are constructed in such a way that they can be used in a specific environment or few different environments (e.g. liquid, gas or vacuum environment). The building blocks are also constructed in such way that chemical, electrochemical, biological or bioelectrochemical methods can be applied to the building block modification and / or detachment and / or manipulation and / or assembly and / or postprocessing.

The special building blocks will enlarge the overall size of the assembled devices and may limit the built-in functionality. The limitation may be overcome by designing the building blocks in a rational way to reduce excessive elements and improve the block functionality as well as by improving apparatus and appliances for the building block assembly.

In the claims, the term "comprises/comprising" does not exclude the presence of other elements or steps. Furthermore, although individually listed, a plurality of means, elements or method steps may be implemented by e.g. a single unit. Additionally, although individual features may be included in different claims or embodiments, these may possibly advantageously be combined, and the inclusion in different claims does not imply that a combination of features is not feasible and/or advantageous. In addition, singular references do not exclude a plurality. The terms "a", "an", "first", "second" etc. do not preclude a plurality.

Although the present invention has been described above with reference to specific embodiment and experiments, it is not intended to be limited to the specific form set forth herein. Rather, the invention is limited only by the accompanying claims and, other embodiments than those specified above are equally possible within the scope of these appended claims.

Claims

PATENT CLAIMS

1. A method of assembling a composite structure comprising components, at least some of which are smaller than about 50 μηι, comprising steps in any sequence:

providing a component at an attachment position;

coupling a manipulator to the component;

separating the component from its attachment position;

moving the component by the manipulator in space to a mounting position;

attaching the component to a mounting structure at the mounting position;

decoupling the manipulator from the component;

characterized by

at least partially covering the component by a protective structure.

2. The method according to claim 1, further comprising at least one of the following method steps:

providing means for the component protection during the structure assembly;

encapsulating the component to protect the component functionality and providing means for prompt and reliable component reallocation and functional connection;

coupling the component functionality to the functionality of the structure at the mounting position;

component processing in order to make the assembled parts suitable for further assembly steps; and

component post-processing in order to make the assembled component suitable for operation.

3. The method according to claim 1 or 2, wherein the protective structure or layer is arranged for preserving critical parts of the component during subsequent processing and handling, such as detachment, manipulation, placement, functional connection and operation.

4. The method according to any one of the previous claims, wherein the protective structure is a thin film coating or a sheet of material, such as a metal plate, which may stay in place or be removed after the detachment step.

5. The method according to any one of the previous claims, wherein the covering step is performed by deposition of a metallic layer to at least a part of the component, or wherein the covering step is performed by applying a protective structure by the method steps according to claim 1.

6. The method according to any one of the previous claims, wherein the covering step is performed during a manufacture of the component, either directly after the manufacturing of the component or as an integral part of the manufacturing of the component.

7. The method according to any one of the previous claims, wherein the component comprises a lug having no functionality, further comprising:

coupling the manipulator to the lug of the component and separating the component from the manipulator by decoupling the manipulator from the lug or removing the lug or part of the lug.

8. The method according to any one of the previous claims, wherein the method is used in order to repair structures by replacing faulty structures with new structures.

9. The method according to any one of the previous claims, wherein the method is used in order to build complicated structures that later can be employed as a stamp in a replicating technology, such as nano-imprint lithography.

10. The method according to any one of the previous claims, wherein the method is used in order to fabricate device for in vivo and ex vivo applications.

11. The method according to any one of the previous claims, wherein the method is used in order to fabricate self-powered devices.

12. The method according to any one of the previous claims, wherein the method is used in order to fabricate wireless devices.

13. A device for performing the method according to claim 1 for assembling a composite structure comprising components, at least some of which are smaller than about 50 μηι, the device comprising:

a component arranged at an attachment position; a manipulator, which may be coupled to the component for separating the component from its attachment position and which can move the component in space to a mounting position for attachment of the component to a mounting structure at the mounting position;

a means for decoupling the component from the manipulator at the mounting position;

characterized by

a protective structure, which at least partly covers the component.

14. The device according to claim 13, further comprising at least one of the following:

means for the component protection during the structure assembly;

means for the component processing enabling the component encapsulation for the component protection and prompt and reliable component reallocation, fixation and coupling to the structure at the mounting position;

means for the component processing enabling the component attachment to a mounting structure at the mounting position;

means for the component processing enabling coupling of the component functionality to the functionality of the structure at the mounting position;

means for the component processing in order to make the assembled parts suitable for further assembly steps;

means for the component post-processing in order to make the assembled component suitable for operation.

15. The device according to claim 13 or 14, wherein the protective structure is a thin film coating or a sheet of material, such as a metallic layer.

16. The device according to any one of claims 13 to 15, wherein the film coating or sheet of material is at least partly removed.

17. The device according to any one of claims 13 to 16, wherein the component is provided with a lug, which forms a coupling arrangement for the manipulator, and which may be removed or left intact after assembly.