WO2011023474A1

WO2011023474A1 - Device and method for detecting and identifying three-dimensional profiles

Info

Publication number: WO2011023474A1
Application number: PCT/EP2010/060666
Authority: WO
Inventors: Thorsten Pretsch; Werner Müller
Original assignee: Bundesanstalt für Materialforschung und -Prüfung (BAM)
Priority date: 2009-08-26
Filing date: 2010-07-22
Publication date: 2011-03-03
Also published as: DE102009038878A1

Abstract

A device for detecting three-dimensional profiles comprises a layer (110, 210, 310, 510), which is made from a shape-memory polymer and which, in a starting state, has a substantially smooth surface (112, 512) and into which a three-dimensional surface structure of an object (10) can be impressed, a scanner (120), which is designed to detect a three-dimensional profile (15) of the surface structure impressed into the shape-memory polymer layer (110, 210, 310, 510), and a restoring means (130, 230, 330, 530) for converting the shape-memory polymer layer (110, 210, 310, 510) from the impressed state to the starting state.

Description

Apparatus and method for detecting and identifying three-dimensional

profiles

The present invention relates to an apparatus and method for detecting and identifying three-dimensional profiles, in particular fingerprints of persons.

The surface texture of objects can provide valuable information about their

Origin, structure or other properties included. The investigation of

Surface structure is therefore a common part of the investigation of unknown

Items. For example, impression methods are used in which with the help of impression materials on gypsum, wax or polymer base an impression of the

Object is taken. In this way, the surface texture of the

Article converted into a three-dimensional negative profile of the impression mass.

Also known is the use of fingerprints for identification or

Authorization of persons. As a classic method, the decrease of the fingerprints by means of black color is known. The fingertips are colored with black paint and the fingerprint is applied to a paper by rolling the fingertip. The two-dimensional fingerprint thus produced can then be scanned in, for example, via a flatbed scanner and further processed electronically.

It is also known to capture fingerprints by means of the so-called FTIR (frustrated total internal reflection) method. This is the zu

examining fingers placed on a glass plate (prism), behind which a laser

Surface texture of the skin scans. The grooves of the finger are in direct contact with the glass plate and can be determined as such.

In view of the above, the present invention proposes a device according to claim 1, a device according to claim 17 and a method according to claims 19 and 29. Other aspects, advantages and details of the present invention will become apparent from the dependent claims, the description and the appended

Drawings. According to one embodiment, a device for detecting three-dimensional profiles comprises a layer of a shape memory polymer (FGP), which in a starting state has a substantially smooth surface and into which a three-dimensional surface structure of an object can be embossed. The

The apparatus further includes a scanner configured to detect a three-dimensional profile of the surface structure embossed in the shape memory polymer layer, and recovery means for transferring the shape memory polymer layer from the embossed state to the initial state.

With the help of such a device, a three-dimensional negative profile of

Surface structure of the object to be embossed and read out. Since not only a two-dimensional projection of the three-dimensional object is detected, the detected profile contains additional information about the height profile. However, unlike the impression material of conventional impression methods, the FGP layer can be returned to its original state after reading the impressed profile and then

be reused.

According to one embodiment of the present invention, the restoration means may comprise a heater adapted to heat the shape memory polymer layer. For example, the heater may include at least one Peltier element, a magnetic coil and / or a voltage source for applying a voltage to the shape memory polymer layer. By means of the heater, the FGP layer can be heated above a switching temperature of the shape memory polymer. In particular, this switching temperature could be a glass transition temperature or a melting temperature of crystalline soft segments of the shape memory polymer.

According to another embodiment, the restoration means comprises a source of UV light. Certain FGPs, for example butyl acrylates, their side chains

Have cinnamic acid groups, can crosslink when exposed to UV light of a first wavelength (shape fixing) and solve these bonds when exposed to UV light of a second wavelength again (preparation of the initial form).

According to embodiments of the present invention, the scanner for detecting the embossed surface profile may be a laser scanner or a mechanical scanning system be. Such systems are basically known and are selected according to the purpose of the device according to the expert.

According to one embodiment of the present invention, the device may further comprise a means for fixing the embossed surface structure in the

Having shape memory polymer layer. In particular, this fixing agent may comprise a cooling. If the cooling is designed, for example, as a Peltier element, then heating and cooling of the FGP layer can be effected by the same Peltier element. If the heating comprises several Peltier elements, then the cooling can also take place via these several Peltier elements. In this way, the structure of the device is simplified. As already described above, the fixing agent may also comprise a UV light source which emits light of a wavelength at which the FGP cross-links.

According to one embodiment, the shape memory polymer may be a shape memory thermoplastic polymer, in particular from the group of linear block copolymers, in particular polyurethanes and polyurethanes with ionic or mesogenic components, block copolymers of polyethylene terephthalate and polyethylene oxide, block copolymers of polystyrene and poly (1,4-butadiene), ABA triblock copolymers from poly (2-methyl-2-oxazoline) (A block) and polytetrahydrofuran (B block), multiblock copolymers

Polyurethanes with poly (ε-caprolactone) switching segment, block copolymers of

Polyethylene terephthalate and polyethylene oxide, block copolymers of polystyrene and poly (1,4-butadiene), polyurethane systems, the hard segment-forming phase of

Methylendiphenyldiisocyanat (MDI) and a diol, in particular 1,4-butanediol, or a diamine and a switching segment based on an oligoether, in particular

Polytetrahydrofuran or an oligoester, in particular polyethylene adipate,

Polypropylenadipat, Polybutylenadipat, Polypentylenadipat or Polyhexalenadipat consists, materials with a hard segment-forming phase of toluene-2,4-diisocyanate, MDI, diisocyanates, in particular from MDI or hexamethylene diisocyanate in carbodiimide-modified form and from chain extenders, in particular ethylene glycol, bis ( 2-hydroxyethyl) hydroquinone or a combination of 2,2-bis (4-hydroxyphenyl) propane and ethylene oxide are constructed whose switching segment-determining blocks of oligoethers, in particular polyethylene oxide, polypropylene oxide, polytetrahydrofuran or a combination of 2,2-bis ( 4-hydroxyphenyl) propane and propylene oxide, or of oligoesters, in particular polybutylene adipate, consist of materials of polynorbornene, graft copolymers of polyethylene / nylon-6, block copolymers with polyhedral oligomeric silsesquioxanes (POSS), including the combinations polyurethane / POS S, epoxide / POSS,

Polysiloxane / POSS, polymethyl methacrylate / POSS, silicone-based FGPs, and poly (cyclooctene) materials.

According to another embodiment, the shape memory polymer may be an elastomeric shape memory polymer, in particular from the group consisting of polyvinyl chloride, polyethylene-polyvinyl acetate copolymers, covalently crosslinked copolymer systems of stearyl acrylate and esters of methacrylic acid, trans-polyisoprene / polyurethane-based, segregated FGP, poly (ether esters) such as Poly (ethylene oxide) / poly (ethylene terephthalate) copolymers,

Norbornyl / POSS copolymers, poly (methylene-1,3-cyclopentane) and its copolymer with polyethylene, styrene / butadiene copolymers, thiol-ene / acrylate copolymers, polynorbornene, polymer networks produced from poly (ε-caprolactone) (PCL) and dimethacrylates, Poly (ε-caprolactone) (PCL) -based FGPs, acrylate-based FGPs, (meth) acrylate networks, cross-linked polyethylene, epoxy-based FGPs, a polyurethane / phenoxy blend, or a polyurethan / polyvinylchloride (PVC) blend.

According to yet another embodiment, the shape memory polymer may be a thermoset, in particular a styrene-based, shape memory polymer.

According to embodiments of the present invention, the shape memory polymer is formed as a shape memory polymer composite. In this connection, it should be noted that for the following application, the terms shape memory polymer and shape memory polymer composite are used interchangeably. In other words, instead of a shape memory polymer and a correspondingly suitable

Shape memory polymer composite or vice versa. FGP composites are materials in which one or more fillers are embedded in the FGP matrix. Suitable fillers are for example magnetic

Nanoparticles, ferromagnetic particles, in particular AlN particles, Ni particles, Fe ₂ O ₃ particles, Fe ₃ O ₄ particles, NiZn particles and iron oxide particles. Likewise, so-called nanoclays can be used as fillers. The nanoclays can be formed, for example, based on silicon nitride, silicon carbide, silicon dioxide, zirconium oxide and / or aluminum oxide. Other possible fillers are oligomeric silsesquioxanes, graphite particles, carbon nanotubes, synthetic fibers, in particular carbon fibers, glass fibers or Kevlar fibers, but also metal particles. Other suitable fillers are thermochromic materials, in particular rutile, zinc oxide, 9,9'-bixanthylidene, 10,10'-bianthronylidene or bis-diethylammonium tetrachloro-cuprate (II). Of course, combinations of such fillers can be used. The fillers are suitable for adjusting the mechanical, electrical, magnetic and / or optical properties of the FGP and adapting them to a particular application.

For example, FIG bis-diethylammonium-tetrachloro cuprate (II) at about 53 ⁰ C a fixed solid phase transformation, which is accompanied by a color change from green to yellow.

Devices according to further embodiments of the present invention include a shape memory polymer selected from the group consisting of: a poly (ester urethane) copolymer, a nematic liquid crystal elastomer

Photo deformation polymer. Such materials can have a two-dimensional memory and a two-way effect.

Furthermore, the shape memory polymer can be formed as a thermo-sensitive and / or UV-sensitive and / or magneto-sensitive and / or electroactive material. Optically controllable shape memory polymers include e.g. Butyl acrylates, which crosslink at their side chains via cinnamic acid groups under UV light of a certain wavelength and solve the bond when irradiated with a different wavelength again. Magnetically controllable shape memory polymers can, for. By incorporation of finely divided magnetic nanoparticles of e.g. Iron oxide can be obtained in the plastic. Such materials are then able to convert the energy of a magnetic field into heat. About the proportion of nanoparticles and the strength of the magnetic field, a desired temperature in the polymer can be adjusted specifically. As electroactive polymers (EAP), e.g.

Shape memory polymer composites are used with carbon nanotubes. The aforementioned materials thus open up various possibilities, the

To trigger shape memory effect.

According to another embodiment, the shape memory polymer layer has a thickness in the range of 0.5 mm to 50 mm. In particular, the layer may have a thickness in the range of 1 mm to 5 mm, in particular 2 mm to 3 mm. Coating thicknesses in this range should be sufficient for most applications, as they allow the imprinting of a surface structure with profile heights up to about 10 mm. Typically, the layer thickness is selected to be about five times the largest length in the structure to be imaged. With thick FGP layers, care should also be taken that, for example, the heating power and the arrangement of the heating or the cooling capacity and the arrangement of the cooling sufficient to heat the entire layer sufficiently quickly or to cool.

On the basis of the devices described above, a device for

Identification and / or authorization of persons or objects according to an embodiment of the present invention. As stated, such a device comprises a device for detecting three-dimensional profiles as described above. Furthermore, such a device has a storage means for

Save three-dimensional profiles and a comparison means. The

Comparison means are arranged to compare a detected three-dimensional profile with one or more stored three-dimensional profiles and to determine whether a detected three-dimensional profile matches a stored profile.

For example, the three-dimensional surface structure whose profile is detected may be an area of a human finger.

Such a device is able to recognize and / or authorize persons and / or objects based on their surface profile. The device can determine the objects or persons based on actual three-dimensional profile data and is not dependent on two-dimensional projections. In the identification or authorization of persons is no dye contact as in the classic

Given fingerprinting.

Compared to the two-dimensional FTIR method, the above device has the advantage that typical errors caused by finger movements during scanning no longer occur. In particular, errors due to differences in brightness and contrast are thus avoided. Such errors cause the FTIR method more often does not provide the desired result in the first scan attempt and the scan must be repeated. Since it is not necessary to repeat the scan with the described device, identification and authorization of a person can be faster than with the FTIR method. In addition, the scanner is located below the glass plate in the FTIR process, which more often causes a person whose fingers are straight scanned, randomly looking into the scanner. This is usually perceived as unpleasant. By contrast, in the device described, the scanner is typically arranged on the same side from which the finger is placed on the FGP layer and is used only after impressing the impression. Thus, it can be avoided that persons accidentally look into the scanner during a scanning operation.

According to another aspect of the present invention, there is provided a method of detecting a three-dimensional surface structure of an object. The method comprises providing a layer of a shape memory polymer, embossing a three-dimensional surface structure of an object in the

Shape memory polymer layer; and scanning a three-dimensional profile of the surface structure embossed in the shape memory polymer layer. In this case, for example, the FGP layer may be heated prior to imprinting via a switching temperature of the shape memory polymer, wherein the switching temperature may be a glass transition temperature or a melting temperature of crystalline soft segments of the shape memory polymer. In this way, the FGP can be prepared to store the three-dimensional profile. Alternatively, for certain FGPs, irradiation with UV light can also occur, which leads to disruption of crosslink bonds in the FGP. Subsequently, the embossed three-dimensional surface structure before scanning in the

Shape memory polymer layer can be fixed. This can be done, for example, by cooling the FGP layer below a glass transition temperature or a crystallization temperature of the shape memory polymer. Alternatively, for certain FGPe also a

Irradiation with UV light, which leads to the crosslinking of the FGPs. After scanning, the FGP layer can be returned from the embossed state to an initial state in which it has a substantially smooth surface. In one

Embodiment, this is achieved by heating the switching temperature of the FGPs, for example by applying an electrical voltage or a magnetic field. In another embodiment, the FGP layer is converted by irradiation with UV light in the initial state.

The method described above can be used to identify and / or authorize persons or objects. Initially, a three-dimensional profile is detected as described above. The detected profile is compared with one or more stored three-dimensional profiles, and it is determined whether the detected three-dimensional profile Profile matches a saved profile. For example, if the three-dimensional surface structure is an area of a human finger, such as the foremost member of an index finger, then a person may be identified and / or authorized.

Compared to the two-dimensional FTIR method, the above method has the advantage that typical errors that occur in the image of the pressed-finger, no longer occur. Also avoided is the contact of the person to be identified with a dye.

Further advantageous embodiments, details, aspects and features of the present invention will become apparent from the dependent claims, the description and the accompanying drawings. It shows

Fig. 1 shows a device for detecting three-dimensional profiles according to a

Embodiment of the present invention.

Fig. 2 shows a device for detecting three-dimensional profiles according to another embodiment of the present invention.

Fig. 3 shows a device for detecting three-dimensional profiles according to yet another embodiment of the present invention.

4 shows various steps in the implementation of a method according to a

Embodiment of the present invention.

5 shows a device for identifying and / or authorizing persons or

Articles according to an embodiment of the present invention.

As shape memory polymers (FGPe) are generally referred to plastics, which may seem to "reminisce" after their transformation to their former outer shape and thus have a shape memory.To recall the memory of the former form, the FGP must be exposed to a stimulus For example, stimulus can be over a heat input, irradiation with light, a change in pH, electromagnetic fields, a modification of the chemical environment or the like can be set.

Fig. 1 shows a device 100 for detecting three-dimensional profiles according to an embodiment of the present invention. The device 100 comprises a layer 110 of a shape memory polymer. Typically, the layer 110 has a thickness in the range of 0.5 mm to 50 mm, in particular 1 mm to 5 mm, and in particular 2 mm to 3 mm. In its initial state, the layer 110 has a substantially smooth surface 112. For example, if the shape memory polymer is a thermoplastic, such as a poly (ester urethane), layer 110 may be prepared by dissolving the thermoplastic in a solvent, such as tetrahydrofuran, and then evaporating in a template of layer 110 made specifically for this purpose. In one experiment, it was shown that dissolved in 5 ml of tetrahydrofuran 200 mg poly (ester urethane) and that the film obtained after evaporation of the solvent has the desired shape memory properties. Alternatively, the layer 110 may also be obtained by direct melting of the FGP, for example in a vacuum oven, and pouring into a stencil. In a test carried out to this melting and casting were carried out at 240 ⁰ C and 20 mbar. The layers 110 produced in this way were almost unchanged from the starting material

Shape memory properties.

The surface 112 of the layer 110 is intended to be a three-dimensional

Surface structure of an object can be imprinted into it. Opposite to the surface 112, a scanner 120 is arranged. By means of the scanner 120, a three-dimensional profile of the surface structure embossed into the FGP layer 110 can be detected. The scanner 120 may be, for example, a laser scanner or a mechanical scanning system. Furthermore, the apparatus 100 has a restoring means 130 which transfers the FGP layer 110 from the embossed state in which the surface 112 has a three-dimensional profile to the initial state in which the surface 112 is again substantially smooth. In other words, through the

Restoring means 130 deleted the impressed in the "memory" of the FGP layer 110 profile again. For many FGPs, the reverse deformation is triggered by exceeding a so-called switching temperature. Among these thermosensitive FGPs, one can generally distinguish between FGPs for which the switching temperature corresponds to a glass transition (T _trans = T _g ), and FGPen for which the switching temperature corresponds to the melting temperature of crystalline soft segments (TVans ⁼ T _m ) - in the latter case FGPe two components, wherein a first component is an elastic polymer (hard segment) and the second component is a hardening wax (soft segment). If the FGP is deformed, the elastic polymer is "arrested" by the wax in its deformed form, and when the FGP is subsequently heated, the wax softens and becomes resilient

Spring force of the elastic component no longer counteract. The FGP takes on its original form.

In both cases, the programming is done by above the switching temperature of a switching segment deforms the polymer material and then while maintaining the deformation forces below this temperature (in the case T _trans = T _g ) or under the

Crystallization temperature of the soft segments (T _trans = T _c ) is cooled to fix the temporary shape. Reheating above the switching temperature (T _trans = T _g or T _m ) results in a phase transition and restoration of the original shape.

In the embodiment shown in Fig. 1, the FGP layer 110 is formed of such a thermosensitive FGP. Correspondingly, the restoration means 130 comprises a heater which is suitable for heating the FGP layer 110 in particular above its switching temperature. In the embodiment shown, the heater is designed as a Peltier element, but also several Peltier elements can be used. The use of one or more Peltier elements has the advantage that the Peltier element 130 can be used not only as heating but also as cooling, for example to cool the FGP layer 110 below the switching temperature and thus to fix an impressed profile. The embossed FGP layer 110 can then be returned to its original state by heating by means of the Peltier element 130.

With the help of such a device, a three-dimensional negative profile of

Surface structure of the object to be embossed and read out. Since not only a two-dimensional projection of the three-dimensional object is detected, the detected profile contains additional information about the height profile. Unlike the impression mass However, conventional impression method, the FGP layer can be brought back to its original state after reading the embossed profile and then

be reused. For example, a polyether-based polyurethane FGP is known to undergo several hundred cycles without significantly degrading the shape memory property. The device 100 allows a high resolution in a short time, a more pleasant handling and a greater depth of analysis, as information about the three-dimensional nature of a scanned

Let body part or object be compared.

Fig. 2 shows a device 200 for detecting three-dimensional profiles according to another embodiment of the present invention. The structure of the device 200 is basically similar to the device shown in FIG. In particular, the device 200 also has an FGP layer 210 and a scanner 220 for detecting a three-dimensional surface profile of the FGP layer 210. However, the layer 210 is formed of an FGP composite. In the embodiment according to FIG. 2, electromagnetically influenced fillers 215 are embedded in the FGP matrix. Suitable fillers 215 are, for example, magnetic nanoparticles, ferromagnetic particles, in particular AlN particles, Ni particles, NiZn particles, Fe ₂ O ₃ particles, Fe ₃ O ₄ particles, oligomeric silsesquioxanes, graphite particles, carbon nanotubes or metal particles , The dispersivity of Fe ₂ O ₃ particles or Fe ₃ O ₄ particles in the FGP matrix can be increased by coating with SiO ₂ or else by coating with polymers such as poly (ε-caprolactone). Other suitable fillers are thermochromic materials, in particular rutile, zinc oxide, 9,9'-bixanthylidene, 10,10'-bianthronylidene or bis-diethylammonium tetrachloro-cuprate (II). Of course, combinations of such fillers can be used. By means of the electromagnetically influenced fillers 215, the FGP layer 110 can be heated, for example, by inductive and / or capacitive heating. Therefore, in the embodiment according to FIG. 2, the Peltier element 130 is also replaced by a magnet coil 230. By means of the electromagnetic radiation generated by the coil 230, the FGP layer 210 is heated slightly above the switching temperature, for example, due to the filler 215 dispersed therein. After impressing the surface profile, the temperature drops in the FGP layer 210 below the switching temperature, so that the embossed profile is sufficiently fixed for the scanning process. Of course, cooling can additionally be provided in order to cool the FGP layer 210 below the switching temperature. According to other embodiments However, one or more fillers are added to the FGP composite of the layer 210, which change the mechanical properties of the composite so that the embossed profile is sufficiently maintained at least for the duration of the scan.

According to yet another development, which is not shown, however, a voltage source for applying a voltage to the FGP layer 210 may additionally or alternatively also be provided. In this way, for example, a heating by means of

Resistance heating done.

3 shows a device 300 for detecting three-dimensional profiles according to a further exemplary embodiment of the present invention. The basic structure is similar to the devices already described insofar as an FGP layer 310 and a scanner 320 for detecting the embossed profile are included. However, that shows

Restore means a source 330 for UV light 335 on. Certain FGPs, for example butyl acrylates whose side chains have cinnamic acid groups, can crosslink on irradiation with UV light of a first wavelength and redissolve these bonds upon irradiation with UV light of a second wavelength. If a three-dimensional surface profile is impressed into the FGP layer 310, this can be fixed by irradiating UV light of the first wavelength. After the subsequent scanning process, by irradiating UV light of the second wavelength, the FGP layer 310 can be returned to the initial state. The UV source 330 is therefore typically configured to generate both the first and second wavelengths. For this purpose, the UV source 330 may have, for example, a first source for the first wavelength and a second source for the second wavelength, wherein the first and the second source are selectively controllable.

4 shows various steps in carrying out a method according to an embodiment of the present invention. In FIG. 4A, a device 100, as described with reference to FIG. 1, is first provided. The device 100 in particular comprises a layer 110 of a shape memory polymer. The FGP layer 110 is now heated by means of the Peltier element 130 above a switching temperature of the FGP. This heating is indicated in FIG. 4A by the arrows which indicate the heat flow from the Peltier element 130 into the FGP layer 110. As already stated above, the Switching temperature is a glass transition temperature or a melting temperature of

Be soft segments of the shape memory polymer.

In a next step, shown in FIG. 4B, a three-dimensional one will now be shown

Surface structure of an object 10 embossed in the FGP layer 110. While the object 10, for example, a fingertip, exerts pressure on the FGP layer 110, the FGP layer 110 becomes below a glass transition temperature for fixing

Cooling temperature of the shape memory polymer cooled. This is indicated again in FIG. 4B by arrows which indicate the heat flow from the FGP layer 110 to the Peltier element 130. In this way, the embossed three-dimensional

Surface structure before scanning in the FGP layer 110 fixed.

A next step of the method is shown in FIG. 4C. This shows that a three-dimensional profile 15 of the surface structure of the object 10 is now embossed and fixed in the surface 112 of the FGP layer 110. This three-dimensional profile of the surface structure impressed into the FGP layer 110 is now detected by the 3D scanner 120. The scanner 120 scans the embossed profile 15 optically by means of laser light 125. Additionally or alternatively, the scanning of the profile 15 can also be done mechanically.

In a final step, shown in FIG. 4D, the embossed FGP layer 110 is now restored to the initial state by heating above the switching temperature, where the shape memory polymer layer has a substantially smooth surface 112.

The basis of the Fign. 4A to 4D can in principle also with

Devices are carried out in which the FGPe be heated, for example by means of the application of an electrical voltage or a magnetic field. Likewise, the described method for FGPe can be carried out, in which the fixation and re-deformation of the FGP layer by means of the irradiation of UV light takes place. The adjustments necessary in these cases, the process steps will make the skilled person depending on the application in a suitable manner.

5 shows a device 500 for identifying and / or authorizing persons or objects according to an embodiment of the present invention. there For example, the apparatus comprises one of the device 300 for detecting three-dimensional profiles according to an exemplary embodiment of the present invention. The apparatus further comprises a storage means 550 for storing three-dimensional profiles and a comparison means 540 arranged to compare a detected three-dimensional profile with one or more stored three-dimensional profiles and to determine whether a detected three-dimensional profile matches a stored profile. The three-dimensional profiles can be formed in particular by fingerprints of persons. On the other hand, even complex three-dimensional surface structures of objects can be used as keys.

A method for identifying persons or objects carried out with the device described above comprises in particular the detection of a three-dimensional profile as already described above with reference to FIGS. 4A to 4D has been explained. The profile thus detected is forwarded by the scanner 520 and the comparison means 540. The comparison means 540, for example a suitably equipped computer, has access to a storage means 550 in which three-dimensional profiles are stored. In one

Memory mode, the comparison means is set up to store the profile detected by the scanner 520 on the memory means 550. Furthermore, typically person or object specific data are assigned to the detected profile and also stored on the storage means 550. In an identification or authorization mode, the comparison means 540 is arranged to compare the profile acquired by the scanner 520 with one or more three-dimensional profiles stored on the storage means 550. In particular, the comparison means 540 is arranged to determine whether the detected three-dimensional profile matches a stored profile. In the case of agreement, an object or a person can be identified and / or authorized according to the application. In particular, this identification or authorization can take place on the basis of a fingerprint.

With the described device so three-dimensional fingerprints of

Persons or imprints of objects are taken. In a free scan in which the body part to be scanned is e.g. placed on a glass plate, effect

unintentional movements easily blurred image. In processes that work with stains, unpleasant residues remain on the body part. At the here

described method, the heated shape memory polymer by the exercise deformed by pressure. By cooling, the impression in the polymer can then be quickly fixed temporarily. After three-dimensional scanning of the impression, the heating of the polymer to a temperature above the material-specific switching temperature leads to the recovery of the initial state.

Accordingly, there are advantages in that the scan is performed on an immovable accurate impression, which allows for better data capture especially in hectic people or underage or disabled people. Furthermore, no unpleasant dye residues remain on the body part. The 3-D scan also provides information that goes far beyond the achievable results of traditional methods. This makes the described method safer compared to previously used methods. Finally, the polymeric shape sensing body can be reused as often as desired.

In the embodiments of the present invention described above, shape memory polymers and / or shape memory polymer composites are always used.

At present, most of the materials described in the literature exhibit a thermally induced shape memory effect, that is, upon heating of the

Polymer material above the defined switching temperature (transition temperature) takes place driven by Entropieelastizität provision. Shape memory polymers are typically polymer networks in which chemical (covalent) or physical (noncovalent) crosslinking sites determine the permanent shape. Phase-segregated, linear block copolymers are composed of hard and soft segments. In general, a distinction is made between materials in which rebounding is triggered by

Exceeding the switching temperature, which corresponds either to a glass transition (TV _ans ⁼ T _g ) or the melting temperature of the soft segments (T _trans = T _m ). In both cases, the programming is done by above the transition temperature of a switching segment deforms the polymer material and then while maintaining the

Deformation forces below this temperature (in case T _trans = T _g ) or under the

Crystallization temperature of the soft segments (T _trans = T _c ) is cooled to fix the temporary shape. Renewed heating above the transition temperature (T _trans = T _g or T _m ) results in a phase transition and restoration of the original shape.

Shape memory polymers whose switching temperature for shape recovery slightly above the temperature of the human body and their switching temperature for the Form fixation in a perceived as pleasant area, for example, O ⁰ C, for example, can be used for impressing fingerprints. However, it can also be selected materials in which T _trans = T _g, and which have, for example, a switching and shape retention temperature of about 4O ⁰ C. At the same time, the surface hardness should be selected for the FGPe in such a way that impressions are produced with sufficient accuracy.

In the above-described embodiments of the present invention, in particular thermoplastic shape memory polymers, in particular from the group of linear block copolymers, in particular polyurethanes and polyurethanes with ionic or mesogenic components, block copolymers of polyethylene terephthalate and

Polyethylene oxide, block copolymers of polystyrene and poly (1,4-butadiene), ABA triblock copolymers of poly (2-methyl-2-oxazoline) (A block) and polytetrahydrofuran (B block), multiblock copolymers of polyurethanes with poly ( ε-caprolactone) -Schaltsegment,

Block copolymers of polyethylene terephthalate and polyethylene oxide, block copolymers of polystyrene and poly (1,4-butadiene), polyurethane systems whose hard segment-forming phase of methylene diphenyl diisocyanate (MDI) and a diol, in particular 1,4-butanediol, or a diamine and a switching segment on the Base of an oligoether, in particular polytetrahydrofuran or an oligoester, in particular polyethylene adipate

Polypropylenadipat, Polybutylenadipat, Polypentylenadipat or Polyhexalenadipat consists, materials with a hard segment-forming phase of toluene-2,4-diisocyanate, MDI, diisocyanates, in particular from MDI or hexamethylene diisocyanate in carbodiimide-modified form and from chain extenders, in particular ethylene glycol, bis ( 2-hydroxyethyl) hydroquinone or a combination of 2,2-bis (4-hydroxyphenyl) propane and ethylene oxide are constructed whose switching segment-determining blocks of oligoethers, in particular polyethylene oxide, polypropylene oxide, polytetrahydrofuran or a combination of 2,2-bis ( 4-hydroxyphenyl) propane and propylene oxide, or from oligoesters, especially polybutylene adipate, materials of polynorbornene, graft copolymers of polyethylene / nylon 6, block copolymers with polyhedral oligomeric silsesquioxanes (POSS), including the combinations polyurethane / POS S, epoxide / POSS,

Polysiloxane / POSS, polymethylmethacrylate / POSS, silicone-based FGPs, and poly (cyclooctene) materials.

In the embodiments of the present invention described above, elastomeric shape memory polymers, in particular from the group Polyvinyl chloride, polyethylene-polyvinyl acetate copolymers, covalently crosslinked copolymer systems of stearyl acrylate and esters of methacrylic acid.

In the embodiments of the present invention described above, thermosetting, in particular styrene-based, shape memory polymers can also be used.

In the above-described embodiments of the present invention, shape memory polymers comprising butyl acrylates whose side chains have cinnamic acid groups may also be used.

In the embodiments of the present invention described above, shape memory polymer composites may be used in which one or more fillers are embedded in the FGP matrix. Suitable fillers are, for example, magnetic nanoparticles, ferromagnetic particles, in particular NiZn particles,

Iron oxide particles and magnetite particles. Also called Nanoclays as

Fillers are used. The Nanoclays can be based on, for example,

Silicon nitride, silicon carbide, silicon oxide, zirconium oxide and / or alumina may be formed. Other possible fillers are oligomeric silsesquioxanes, graphite particles,

Carbon nanotubes, synthetic fibers, in particular carbon fibers, glass fibers or Kevlar fibers, but also metal particles. Other suitable fillers are thermochromic materials, in particular rutile, zinc oxide, 9,9'-bixanthylidene, 10,10'-bianthronylidene or bis-diethylammonium tetrachloro-cuprate (II). Of course, combinations of such fillers can be used. The fillers are suitable for adjusting the mechanical, electrical, magnetic and / or optical properties of the FGP and adapting them to a particular application.

Photo deformation polymer. Such materials can have a two-dimensional memory and a two-way effect. Furthermore, the shape memory polymer can be formed as a thermo-sensitive and / or UV-sensitive and / or magneto-sensitive and / or electroactive material. Optically controllable shape memory polymers include, for example, butyl acrylates, which crosslink at their side chains via cinnamic acid groups under UV light of a specific wavelength and redissolve the binding upon irradiation with a different wavelength. Magnetically controllable shape memory polymers can, for. B. be obtained by incorporating finely divided magnetic nanoparticles of eg iron oxide in the plastic. Such materials are then able to convert the energy of a magnetic field into heat. About the proportion of nanoparticles and the strength of the magnetic field, a desired temperature in the polymer can be adjusted specifically. As electroactive polymers (EAP) can eg

To trigger shape memory effect.

The present invention has been explained with reference to exemplary embodiments. These embodiments should by no means be understood as limiting the present invention. In particular, individual characteristics of the various

Embodiments are adopted in other embodiments or different embodiments are combined with each other, as long as the combined

Do not mutually exclude features for technical reasons.

Claims

1. A device for detecting three-dimensional profiles, comprising a shape memory polymer layer (110, 210, 310, 510), which in an initial state has a substantially smooth surface (112, 512) and into which a three-dimensional surface structure of an object (10 ), a scanner (120) adapted to detect a three-dimensional profile (15) of the surface structure embossed in the shape memory polymer layer (110, 210, 310, 510), and restoring means (130, 230, 330, 530 ) to transfer the

Shape memory polymer layer (110, 210, 310, 510) from the embossed state to the initial state.

The apparatus of claim 1, wherein the recovery means (130, 230) comprises a heater adapted to heat the shape memory polymer layer (110, 210).

The device of claim 2, wherein the heater comprises at least one Peltier element (130), a magnetic coil (230) and / or a voltage source for applying a voltage to the shape memory polymer layer (110, 210).

The apparatus of claim 1, wherein the restoration means (330) comprises a source (330) for UV light (335).

5. Device according to one of the preceding claims, wherein the scanner (120, 220, 320, 520) is a laser scanner or a mechanical scanning system.

6. Device according to one of the preceding claims, further comprising means (130) for fixing the embossed surface structure in the

Shape memory polymer layer (110).

The apparatus of claim 6, wherein the fixing means (130) comprises cooling.

8. Apparatus according to claim 7, wherein the cooling comprises at least one Peltier element.

9. Device according to one of the preceding claims, wherein the

Shape memory polymer is a thermoplastic shape memory polymer.

10. The device of claim 9, wherein the shape memory polymer is selected from the group consisting of: linear block copolymers, in particular polyurethanes and polyurethanes with ionic or mesogenic components, block copolymers of polyethylene terephthalate and polyethylene oxide, block copolymers of polystyrene and poly (l, 4-butadiene), ABA triblock copolymers of poly (2-methyl-2-oxazoline) (A block) and polytetrahydrofuran (B block), multiblock copolymers of polyurethanes with poly (ε-caprolactone) switching segment, block copolymers of polyethylene terephthalate and polyethylene oxide, block copolymers Polystyrene and poly (l, 4-butadiene), polyurethane systems whose hard segment-forming phase

Methylendiphenyldiisocyanat (MDI) and a diol, in particular 1,4-butanediol, or a diamine and a switching segment based on an oligoether, in particular polytetrahydrofuran or an oligoester, in particular

Polyethylenadipat, Polypropylenadipat, Polybutylenadipat, Polypentylenadipat or Polyhexalenadipat consists, materials with a hard segment-forming phase of toluene-2,4-diisocyanate, MDI, diisocyanates, in particular of MDI or

Hexamethylene diisocyanate in carbodiimide-modified form and from

Chain extenders, in particular ethylene glycol, bis (2-hydroxyethyl) hydroquinone or a combination of 2,2-bis (4-hydroxyphenyl) propane and ethylene oxide are constructed whose switching segment-determining blocks of oligoethers, especially polyethylene oxide, polypropylene oxide, polytetrahydrofuran or a combination from 2,2-bis (4-hydroxyphenyl) propane and propylene oxide, or from oligoesters, in particular polybutylene adipate, consist of materials

Polynorbornene, polyethylene / nylon-6 graft copolymers, block copolymers with polyhedral oligomeric silsesquioxanes (POSS), including the combinations polyurethane / POSS, epoxide / POSS, polysiloxane / POSS, polymethylmethacrylate / POSS, silicone-based FGPs and poly (cyclooctene) materials, a poly (ester urethane) copolymer, a nematic liquid crystal elastomer, a photodeformation polymer.

The device of any one of claims 1 to 8, wherein the shape memory polymer is an elastomeric shape memory polymer.

12. The device of claim 11, wherein the shape memory polymer is selected from the group consisting of: polyvinyl chloride, polyethylene-polyvinyl acetate copolymers, covalently crosslinked copolymer systems of stearyl acrylate and esters of methacrylic acid, trans-polyisoprene / polyurethane-based, segregated FGP, poly (ether esters) such as poly (ethylene oxide) / poly (ethylene terephthalate) copolymers, norbornyl / POSS copolymers, poly (methylene-1,3-cyclopentane) and its copolymer with polyethylene, styrene / butadiene copolymers, thiol-ene / acrylate copolymers, polynorbornene .

Polymer networks made of poly (ε-caprolactone) (PCL) and dimethacrylates, poly (ε-caprolactone) (PCL) -based FGPs, acrylate-based FGPs, (meth) acrylate networks, cross-linked polyethylene, epoxide-based FGPs

Polyurethane / phenoxy blend, a polyurethane / polyvinyl chloride (PVC) blend.

13. Device according to one of claims 1 to 8, wherein the shape memory polymer is a thermosetting, in particular a styrene-based or epoxide-based,

Shape memory polymer is.

14. Device according to one of the preceding claims, wherein the

Shape memory polymer is designed as a shape memory polymer composite.

The device of claim 14, wherein in the shape memory polymer matrix

embedded in at least one filling material which is selected from the group comprising: magnetic nanoparticles, ferromagnetic particles, in particular AlN particles, Ni particles, Fe ₂ O ₃ particles, Fe ₃ O ₄ particles, NiZn particles, iron oxide particles, a Nanoclay comprising silicon nitride, silicon carbide, silicon dioxide, zirconium oxide and / or aluminum oxide, oligomeric silsesquioxanes, graphite particles,

Carbon nanotubes, synthetic fibers, in particular carbon fibers, glass fibers or Kevlar fibers, metal particles, thermochromic materials, in particular rutile, Zinc oxide, 9,9'-Bixanthyliden, 10.1 (T-Bianthronyliden or bis-diethylammonium tetrachloro-cuprate (II), and combinations of said fillers.

16. Device according to one of the preceding claims, wherein the

Shape memory polymer layer (110, 210, 310, 510) has a thickness in the range of 0.5 mm to 50 mm.

17. Device (500) for identifying and / or authorizing persons or

An article comprising a device (500) for detecting three-dimensional profiles according to one of the preceding claims, storage means (550) for storing three-dimensional profiles, comparison means (540) arranged to have a detected three-dimensional profile with one or more stored three-dimensional profiles to compare and determine whether a detected three-dimensional profile matches a stored profile.

18. A device according to claim 17, wherein the three-dimensional surface structure is an area of a human finger.

19. A method for detecting a three-dimensional surface structure of an object, comprising

Providing a layer of a shape memory polymer,

Imprinting a three-dimensional surface structure of an object in the

Shape memory polymer layer,

Scanning a three-dimensional profile of the embossed into the shape memory polymer layer surface structure.

20. The method of claim 19, wherein the shape memory polymer layer is heated prior to imprinting over a switching temperature of the shape memory polymer.

21. The method of claim 20, wherein the switching temperature is a

Glass transition temperature or a melting temperature of the soft segments of the shape memory polymer.

22. The method according to any one of claims 19 to 21, wherein the embossed

three-dimensional surface structure before scanning in the

Shape memory polymer layer is fixed.

A method according to claim 22, wherein the shape memory polymer layer is cooled for fixing.

24. The method of claim 22 or 23, wherein the shape memory polymer layer is cooled to fix below a glass transition temperature or a crystallization temperature of the shape memory polymer.

The method of any one of claims 19 to 24, further comprising transferring the shape memory polymer layer from the embossed state into a

Initial state in which the shape memory polymer layer has a substantially smooth surface.

26. The method of claim 25, wherein the shape memory polymer layer for

Transfer to the initial state via the switching temperature of the

Shape memory polymer is heated.

27. The method of claim 26, wherein the shape memory polymer layer is heated by applying a voltage or a magnetic field to the shape memory polymer layer.

28. The method of claim 25, wherein the shape memory polymer layer by

Irradiation with UV light is converted to the initial state.

29. A method of identifying and / or authorizing persons or objects, comprising acquiring a three-dimensional profile according to any one of claims 19 to 28, comparing a detected profile to one or more stored three-dimensional profiles, and determining whether the detected three-dimensional profile matches a saved profile.

30. The method of claim 29, wherein the three-dimensional surface texture is an area of a human finger.