ADHESIVE SYSTEM FOR ROUGH SURFACES

Abstract

A device having a structured coating for adhering to rough, in particular, biological surfaces, includes a carrier layer, wherein a plurality of protrusions is arranged on the carrier layer, which protrusions each comprise at least one stem having an end face pointing away from the surface, and wherein a further layer is arranged at least on the end face, wherein the layer has a lower modulus of elasticity and is in the form of a film that interconnects the protrusions. The film can also be in the form of a removable film.

Claims

1. A device having a structured coating, comprising: a backing layer bearing a multiplicity of protrusions which comprise at least in each case a stem having an end face pointing away from the surface, wherein the end face bears at least one further layer which is configured as a film, this layer comprising as surface at least one layer which has a lower modulus of elasticity than the respective protrusion.

2. The device of claim 1, wherein the protrusions have an aspect ratio of greater than 1.

3. The device of claim 1, wherein the protrusions have an aspect ratio of at least 1.5.

4. The device of claim 1, wherein the modulus of elasticity of the protrusions and of the backing layer is 1 MPa to 2.5 MPa and the modulus of elasticity of the layer having the lower modulus of elasticity is 40 kPa to 800 kPa.

5. The device of claim 1, wherein the further layer having the lower modulus of elasticity is detachable from the device.

6. The device of claim 1, wherein the device is configured for adhesion to soft substrates.

7. The device of claim 1, wherein the device is configured for adhesion to biological tissues.

8. The device of claim 7 for use in the treatment of eardrum perforations.

9. An implant comprising a device of claim 1.

10. A process for producing a device of claim 1, comprising: applying a layer to a substrate, where the material of the layer has a different solubility than the cured materials of the device; applying the material for the layer having the lower modulus of elasticity; curing the layer; optionally applying further layers; applying the microstructure; selectively dissolving the lowermost layer; and detaching the device.

11. The process of claim 10, wherein instead of the lowermost layer which has a different solubility, a release liner is used.

12. A device, comprising: a backing layer having a surface and a multiplicity of protrusions, each protrusion comprising a stem having an end face pointing away from the surface, wherein the end face of each protrusion comprises a film, said film comprising different layers, with an outermost layer forms a surface of the film and has a lower modulus of elasticity than the protrusion.

13. A method for treating eardrum perforations, comprising: providing the device according to claim 1; and applying the device to a surface of the eardrum.

Description

[0114] The exemplary embodiments are represented schematically in the figures. Identical reference numerals in the individual figures here designate identical or functionally identical elements or elements which correspond to one another in terms of their functions. Specifically:

[0115] FIG. 1 shows an overview of the operation of producing the film-terminated sticking structures;

[0116] FIG. 2 shows an overview of the A sample in plan view at low magnification (A), the bottom arrow showing an upright pillar, the orange arrow a number of collapsed pillars; overview of the A sample in plan view at greater magnification (B), the collapsed pillars being shown from close up (top arrow); overview of the cross section of the A sample at high magnification (C) with dissolved layers of the substrate (adhesive layer and glass substrate) serving only for securement; schematic overview of the A sample, with MDX-4 being marked in gray; (D) with indication of size order, all lengths being in μm. The scale is 500 μm for A and 100 μm for B and C;

[0117] FIG. 3 shows an overview of the B sample in plan view at low magnification (A)—the arrow points to a vacancy caused by collapsed pillars; overview of the B sample in plan view at greater magnification (B)—the arrow points to unevennesses and impurities on the surface; overview of the cross section of the B sample at high magnification (C); schematic overview of the B sample, with MDX-4 being marked in gray; (D) with indication of size order, all lengths being in μm. The scale is 500 μm for A and 100 μm for B and C;

[0118] FIG. 4 shows SEM micrographs of the samples: the A sample: only the microstructured part is depicted (A). B) shows the B sample, where the terminal film, composed of the same material as the microstructured part, has been applied as supporting layer (B). The * points to the terminal layer. C) shows the C sample, following application of the soft, skin-adhering layer (C). The * points to the boundary layer between the two layers. D) allows a view of the bottom side of the terminal layer (D);

[0119] FIG. 5 shows a cross section of the C sample;

[0120] FIG. 6 shows cross sections of different B samples: the layer thickness of the terminating layer may be adjusted here in a defined way by means of spincoating. A spincoating speed of 800 rpm (A) results in a layer thickness of 60.5 μm, 2000 rpm (B)=31.3 μm, 9000 rpm (C)=12.2 μm. The layer thickness may also be reduced further by the addition of a solvent to the polymer;

[0121] FIG. 7 shows various microstructured samples and flat reference samples with comparable thickness and construction; A) A sample with backing layer and microstructure, and A reference sample; B) B sample with backing layer, microstructure and supporting layer, and B reference sample with base and supporting layer; C) C sample with backing layer, microstructure, supporting layer and “bonding layer”, and C reference sample with base, supporting layer and “bonding layer”, in each case from bottom to top;

[0122] FIG. 8 shows stress and detachment energy (work) from the samples from FIG. 7 and table 1 (holding time 1 second);

[0123] FIG. 9 shows rheology measurements for various samples;

[0124] FIG. 10 shows production of film-terminated pillars without supporting layer;

[0125] FIG. 11 shows a schematic representation for the use of the sticking system with partable film;

[0126] FIG. 12 shows an exemplary embodiment of a sticking system with partable film;

[0127] FIG. 13 shows a schematic representation of the peel measurement;

[0128] FIG. 14 shows an embodiment of the production process for the sticking system;

[0129] FIG. 15 shows a schematic construction of the measuring apparatus used for determining the adhesion values;

[0130] FIG. 16 shows an exemplary representation of a stress-time curve (left) and of a stress-displacement travel curve;

[0131] FIG. 17 shows a picture of a microstructure after extraction from the mold (A) and after mechanical treatment (B);

[0132] FIG. 18 shows a light-micrograph of an embodiment of the invention;

[0133] FIG. 19 shows peel measurements with different removal velocities;

[0134] FIG. 20 shows measurement of the vibration properties in eardrums of mice.

[0135] FIG. 1 shows an overview of the operation of producing the film-terminated sticking structures. The completed sticking system consists of a microstructured part (101), made of Silastic MDX4-4210, and a terminal film, consisting here of a combination of the layers of MDX4-4210 (102, 103, step III. a.i.) and subsequent application of the skin-adhesive terminal layer of MG7-1010 (104, VI. a.i.). The terminal layer may also be produced without an MDX4 supporting layer, as shown in III. b.i. The individual steps are described below. The material and the thickness of the respective layers or structures may be varied by varying the materials or the conditions of application.

[0136] I. Wafer Modeling

[0137] The wafer (silicon wafer) is placed in a petri dish, which is filled with the material for the microstructure mold (PDMS, Elastosil 4601, Wacker, Riemerling, Germany, 100). After degassing, a glass plate (111) is placed on and curing takes place at least for 3 hours at 75° C. The cured mold (100) is then removed. The wafer has the later microstructure.

[0138] The mold produced was silanized with fluorosilane (tridecafluoro-1,1,2,2-tetrahydrooctyl)trichlorosilane, 50 μL solution) under reduced pressure (20 mbar).

[0139] II. Production of the Microstructured Part of the Sticking System

[0140] For the material of the microstructure, the two components (Silastic MDX4-4210) are weighed out and mixed in a ratio A:B (10:1). This material was used for all the structures and layers of Silastic MDX4-4210.

[0141] The mold (100) is placed onto a glass plate (111) and filled with the material for the microstructure. The surface is leveled by spincoating (3000 rpm, 120 seconds). This gives a filled mold with a small overlaying. It may be necessary to carry out degassing prior to spincoating.

[0142] In parallel the material for the backing layer (Silastic MDX4-4210) is applied to a plasma-activated glass plate. A layer having a defined thickness is produced by spincoating (9000 rpm, 120 seconds). The plasma-activated glass plate thus coated is then applied to the filled microstructure. The structure is rotated by 180° and placed onto the plasma-activated glass plate (112, oxygen-argon plasma, 2 minutes) and cured (95° C., 1 hour). This causes the microstructure to connect to the backing layer. Effective binding of the structure to the glass plate has been achieved using oxygen-argon plasma, for effective parting of the cured microstructure from the mold.

[0143] The structure is applied to a new glass plate (111). It may be necessary to align the pillars of the microstructure by mechanical action, e.g., brushing or combing (FIG. 17). This gives the A sample, i.e., the microstructure without terminating film. The separate production of the backing layer allows its thickness and material to be easily adapted.

[0144] FIG. 2 shows micrographs (A, B, C) and a schematic representation of the A sample. The microstructure was also used for the other experiments.

[0145] As a reference sample, a film composed of the same material and with similar thickness is produced via a doctor blade.

[0146] III. a.i. Production of the Supporting Layer

[0147] The material of the outer layer (Silastic MDX4-4210, 103) is applied to a glass plate (111) and distributed by spincoating (9000 rpm, 180 s). The coating is cured for an hour at 95° C. Thereafter the material for the supporting layer (Silastic MDX4-4210, 102) is applied and is distributed by spincoating (9000 rpm, 180 s). After that, the microstructure (101) produced, with the pillars, is placed onto the as yet uncured applied layer, so that the pillars at least make contact with the last-applied layer. Thereafter the whole is cured for an hour at 95° C. The structure obtained (B sample) is rotated by 180° and applied with the backing layer to a glass plate.

[0148] FIG. 3 shows micrographs of the B sample.

[0149] For the reference sample, the material of the reference structure (Silastic MDX4-4210) is applied to a glass plate, using a doctor blade, for example. The thickness is similar to the microstructure. Applied to this layer is the material of the bottom layer (Silastic MDX4-4210), which is distributed by spincoating (9000 rpm, 180 s), and the whole is cured for an hour at 95° C. The material for the second layer (Silastic MDX4-4210) is applied to this layer, distributed by spincoating (9000 rpm, 180 s), and cured for an hour at 95° C.

[0150] III. b.i. Production of the Terminal Film without Supporting Layer

[0151] The production is represented schematically in FIG. 10. The material for an auxiliary layer (120, 20% PVA polyvinyl acetate in H.sub.2O) is applied to a glass plate (111), distributed by spincoating (3000 rpm, 60 s), and cured for 10 minutes at 95° C. Applied to this is the material of the adhesion layer (106, Dow Corning MG7-1010), which is distributed by spincoating (4000 rpm, 120 s, 100 rpm/s) and cured for an hour at 95° C. Thereafter the material for a further adhesion layer (105, Dow Corning MG7-1010) is applied and is distributed by spincoating (9000 rpm, 180 s). After that the microstructure produced (101), with the pillars, is placed onto the as yet uncured applied layer (105), so that the pillars at least make contact with the layer. Thereafter the whole is cured for an hour at 95° C. The sample is subsequently cut to size as and when necessary. Thereafter the auxiliary layer (120) is selectively dissolved with water (ultrasound bath for 10-20 minutes). The composite structure detached is applied with the backing layer to a glass plate and dried. This gives the B-OS sample. The thickness of the adhesion layer was on average 27 μm. A B-OS sample with 70 μm thickness was also produced.

[0152] For the reference sample, the material of the reference structure (Silastic MDX4-4210) is applied to a glass plate, using a doctor blade, for example. The thickness is similar to the microstructure. Applied to this layer is the material of the bottom layer (Dow Corning MG7-1010), which is distributed by spincoating (1000 rpm, 120 s), and the whole is cured for an hour at 95° C. Applied to this layer is the material for the second layer (Dow Corning MG7-1010), which is distributed by spincoating (9000 rpm, 180 s) and cured for an hour at 95° C.

[0153] The process with the auxiliary layer may also be used for producing the C sample, if the microstructure with terminating film is placed on.

[0154] IV a.i. Production of the Final Adhesion Layer

[0155] For a viscoelastic layer, a mixture of the viscoelastic material MG7-1010 (Dow Corning, Midland, USA) was prepared. The two-component system was weighed out and mixed in a ratio of 1:1.

[0156] The material for the adhesion layer (104, Dow Corning MG7-1010) is applied to the structure from III. a.i., distributed by spincoating (4000 rpm, 120 s), and cured for an hour at 95° C. This gives the C sample.

[0157] FIGS. 4, 5 and 6 show pictures of different samples. Measurement was carried out using a C sample with the following values: backing layer: 71.99+/−25.16 μm, microstructure height 208.44+/−18.87 μm, supporting layer thickness (102, 103): 19.7+/−4.94 μm, adhesion layer: 21.25+/−12.05 μm.

[0158] Table 1 and also FIG. 8 show the sticking stress and work of various samples (FIG. 7) determined in a tack test on a substrate which models the roughness of skin: determination of the sticking stress and detachment energy of the various microstructured samples in comparison to unstructured samples having a comparable layer construction. It is clearly apparent that the microstructured samples have not only a higher sticking stress but also a higher work on the rough substrate.

[0159] Table 4 shows the measured sticking stress (holding time 1 second) for various samples on substrates with different roughness (R.sub.z) in kPa. Table 3 shows the same data, with the value for the smooth substrate being set at 100% in each case. It is clearly apparent that the samples having an adhesion layer (C, BoS) lose much less adhesion in the case of the rough substrates. The samples were produced with auxiliary layer or release liner and therefore have better adhesion values than the samples in table 1, since with these processes the planarity of the surface of the adhesion layer is better.

[0160] FIG. 11 shows a sticking system with partable terminal film. This system consists of the two components, the terminal film (I) and the microstructured part (II, 101), which are produced separately from one another and brought together by pressing in step 1. The layer construction of the three-layer terminal film is as follows: adhesion layer (131, Dow Corning MG7-1010), elastic supporting layer (132, Silastic MDX4-4210) and adhesion layer (132, Dow Corning MG7-1010). In the second step the sticking system can be used and can be applied to a rough surface (134, e.g., skin). In the course of use, the lowermost layer 132 becomes soiled. Since the connection between the microstructure 101 and the inner adhesion layer 131 is reversible, the microstructure and the film can be parted from one another. In this case the terminal film is disposed of, while the microstructured component can be passed back to the product life cycle. It is also possible for the terminal film to be applied to a microstructure already bearing an applied supporting layer. In the case of this process, the microstructure, which is costly and complicated to produce, can be reused.

[0161] FIG. 12 shows an exemplary embodiment of a sticking system with partable film. The film was produced by three-fold spincoating of the various materials. The terminal film (A) was produced from adhesion layers (131, 132), and a supporting layer (130). B) shows a light-micrograph of a cross section of the film. The two adhesion layers (MG7-1010) appear darker, while the middle supporting layer (MDX4-4210) appears lighter. It has a thickness of 32.32 μm. The film itself is applied to glass. This film was applied to different structures (C, microstructure of Sylgard 184, Tesafilm, Sylgard 184 film with the thickness of the microstructure) and used for the peel measurements (D, see FIG. 13, 180°, 1 mm/step, maximum force measured divided by the width of the sample). It is clearly evident that this system enables the advantages of the system of the invention, while at the same time the film remains detachable.

[0162] FIG. 18 shows a light-micrograph of the detachable film (top) on a microstructure.

[0163] FIG. 19 shows the maximum force measured for different backing systems applied to the film. The pillar is the microstructure composed of Sylgard 184 (height of the protrusions: 187±1.5 μm, backing layer 62±4 μm), the tape is Tesafilm (thickness 59±1.3 μm); Sylgard 184 is a film of Sylgard 184 (thickness 295±8.4 μm).

[0164] In the measurement with a removal velocity of 0.5 mm/step (top), measurement was carried out with a film having the following construction: MG7-1010: 30±4.5 μm/MDX4-4210: 25±5 μm/MG7-1010: 33±7 μm. Measurement was carried out three times.

[0165] In the measurement with a removal velocity of 1 mm/step (bottom), measurement was carried out with a film having the following construction: MG7-1010: 28±3.5 μm/MDX4-4210: 22±4.5 μm/MG7-1010: 27±4 μm. Measurement was carried out three times.

[0166] FIG. 13 shows a schematic representation of the peel measurement. A backing 143 is applied to a hexapod 144. The substrate 142 is applied to a perpendicular area. The substrate used had an elasticity similar to that of skin. Additionally, a modeling of artificial skin (Vitroskin) was made in order to obtain a replica of human skin. The substrate under test is mounted on a strip 141, which is connected to a load cell 140, which can be pulled away parallel to the surface, with measurement of the force. Measurement parameters used were as follows: holding time: 60 s; removal direction 180°, removal velocity 1 mm/step, preload: 1.1 kPa (area 0.75×0.75 cm). Different substrates were measured. The measurements shown in the diagrams were carried out using a model (Turboflex) of Vitroskin (R.sub.a=4.43 μm, R.sub.z=25.3 μm). The width of the strip was 6.5-7 mm. The measurement length was dependent on the substrate and was not more than 7 mm.

[0167] FIG. 14 shows a further embodiment of the process for producing the sticking system. In this case the adhesion layer 132, which is later to be the outermost layer, is applied to a release liner (fluorinated, 135, step I, 3M Scotchpak 9709 release liner film, fluorosilicone-coated polyester film). On this basis it is then possible to apply further layers in accordance with the desired embodiment, such as adhesion layers and supporting layers, for example, and then the microstructure is applied to these layers. The layers may be produced as in the process already described, by spincoating and curing. For application of the microstructure 101, the last applied layer with applied microstructure is cured or the last layer applied is an adhesion layer. FIG. 14 shows as step II the application of a supporting layer 130. Applied to this layer is an adhesion layer 131 (step III). Applied to this layer is the microstructure 101 (step IV). In the alternative Ia, the microstructure 101 is applied directly or after application of a further adhesion layer (105, 106). In the case of different materials, it may be necessary to treat the surface with air plasma before application of the next material. In this way it is possible to prevent soft layers in particular having their properties altered by the successive curing steps.

[0168] The release liner 135 allows the sticking system to be detached easily and without damage. There is also a shortening of the production time and the quality of the system.

[0169] The process with the release liner may also be used for producing the B sample, if the microstructure with terminating film is placed on. An alternative possibility is to apply one or more MDX4-4210 layers as the last layer, which then, as described above, are connected to the microstructure. For better attachment of the MDX4-4210 layer, it may be necessary to carry out a plasma treatment (air plasma) prior to application in order to improve the attachment.

[0170] Through the use of the release liner it has been possible to achieve a more uniform surface of the sample, resulting in a further improvement in the adhesion. For a one-second holding time, BoS sample (30 μm thickness of the adhesion layer with the same microstructure) provides a detachment energy of 641±79 mJ/m.sup.2 and a stress of 14.84±1.18 kPa, while the reference gives only 79.03±39.91 mJ/m.sup.2 and 7.25±3.04 kPa. If the holding time is increased, the detachment energy rises by more than two fold for the BOS sample, more specifically by 56%. The sticking stress shows an increase by 35%. In the case of the BoS-Ref sample, it is possible to measure an increase in the detachment energy of 61% and in the sticking stress of 33%.

[0171] The rheometric data were measured by means of a rheometer (MCR 300, Anton Paar formerly Physica, Graz, Austria). The rheometer has a cone-plate geometry. Before the measurements could be carried out, small amounts of the polymer mixtures were prepared in each case. MG7-1010, MDX4-4210, Sylgard 184 in a mixing ratio of 10:1 and Sylgard 184 in a mixing ratio of 100:1.6 were tested. The latter two mixtures are comparative mixtures, which are used in the literature for microstructure. Each sample was subjected to measurement three times, and was prepared freshly each time for this purpose.

[0172] FIG. 9 shows the graphical evaluation of the rheometry measurements (A: storage modulus (G′), B: complex modulus (G*), C: loss modulus (G″), D: attenuation factor (tan δ=G″/G′)).

[0173] The modulus of elasticity can be estimated for each material with the aid of the storage modulus. These values differ from the values measured with a nanoindenter, but do give the relative proportions.

[0174] On the assumption of E˜3*G′, the values reported in table 2 are obtained for 1 Hz. These values also show that Sylgard 184 10:1 is much harder than MDX4-4210. This corresponds to the measured nanoindenter values of 2.7 MPa and 1.9 MPa, respectively (steel hemisphere, sample thickness >1 mm, sample indentation depth 5000 nm).

[0175] FIG. 15 shows a schematic construction of the measuring apparatus for determining the adhesion values. In the graphic, s describes the position of the platform in the z direction. The platform moves in a positive z direction to bring sample and substrate into contact. As soon as a defined compressive prestress has been reached, the position is held for a defined holding time. The measured variables, such as the forces induced, are detected by means of a load cell and can be read off from a screen. The sample is secured by means of a bonding substrate on a glass slide, which is secured on the platform with a screw apparatus of the sample mount. In order to vary the sample position, the platform together with the sample can also be displaced in x and y directions. The position and the contact of the sample may be observed and adjusted by means of optical elements, such as the prism, camera 1 and 2.

[0176] The platform was moved toward the substrate in a positive z direction with a speed of 30 μm/s until the compressive prestress established was 70±20 mN (or 10±4 kPa). After contact between sample and substrate had been maintained for a defined holding time of either one or thirty seconds, the sample was detached from the substrate. For this the platform was moved in a negative z direction at a removal velocity of 10 μm/s. The measurement setup includes a load cell (max. 3N, Tedea-Huntleigh 1004, Vishay Precision Group, Basingstoke, GB), which is oriented for the capture of low detachment forces. The system recorded the induced normal forces F in z direction relative to the time t and to the platform position s.sub.z. A prism was integrated into the sample mount for the optical detection of the sample position and hence to enable observation of the contact between sample and substrate. With the aid of two cameras (camera 1 and 2) (DMK23UX236, The Imaging Source, Germany), this made it possible to follow and record the measurements on a computer screen. A goniometer was used to adjust the contact area between sample and test substrate.

[0177] FIG. 16 shows an exemplary representation of a stress-time curve and of a stress-displacement travel curve. The respective maximum of the curves indicates the selected compressive prestress, in other words the stress with which the sample was pressed onto the test substrate. The minimum of the curves corresponds in each case to the sticking stress (σ.sub.s). The area included by the curve in the stress-displacement travel diagram and the zero line corresponds to the detachment energy (W.sub.deb) which has to be applied in order to detach the sample from the substrate. The areas of the respective test substrates were determined by optical microscopy. At the time t.sub.0, where the detachment operation begins, but sample and substrate are still completely in contact with one another and the compressive prestress passes through the zero, the position of the platform s.sub.z is referred to as s.sub.0 (FIG. 16). The time point t.sub.end is defined as the point in time at which the detachment operation was concluded (s.sub.end), this being the time at which the sticking stress equals zero.

[0178] Test substrates used were as follows: model of smooth glass (polished glass) in epoxy resin (EGS area 6.2 mm.sup.2, R.sub.a=0.01 μm, R.sub.z=0.10 μm), model of rough glass (etched matt glass) in epoxy resin (EGR, area 6.95 mm.sup.2, R.sub.a=0.22 μm, R.sub.z=1.97 μm) and model of Vitroskin from epoxy resin (area 7.26 mm.sup.2, R.sub.a=9.48 μm, R.sub.z=49.66 μm). Models of mouse eardrums were also used. For these models it was possible to determine a roughness depth of R.sub.z=2.2 μm (pars tensa) and R.sub.z=13 μm (pars flaccida). All Ra and Rz values were measured using a profilometer (SURFCOM 1500SD3, Carl Zeiss, Oberkochen, Germany). Ra and Rz were determined according to DIN EN ISO standard 4287:2010-07.

[0179] The curvature of an eardrum of pars tensa is 35.33±3.5° (determined by light microscopy). In the case of use on eardrums, however, excessively good sticking may also turn out to be disadvantageous on detachment, owing to the great sensitivity of the eardrum. In the case of the device of the invention, the adhesion is adjustable in a simple way by variation of the parameters.

[0180] FIG. 20 shows the vibration properties on mouse eardrums (intact, perforated, perforated with simple film, perforated with microstructure).

[0181] Distortion product otoacoustic emissions (DPOAE) were measured in anesthetized female mice 6-8 weeks of age. The strain was CBA/J. The frequency range investigated was from 8 kHz to 17.9 kHz. Flat films and microstructured systems having a diameter of about 1 mm were used. The diameter of the perforation was between 0.5 and 0.9 mm.

[0182] The microstructure used was a structure having an adhesion layer of 20 μm without supporting layer, protrusion height 40 μm with a diameter of 20 μm, and 20-50 μm backing layer. The smallest distance between the pillars was 20 μm. They had a regular hexagonal arrangement.

[0183] The results show that the films of the invention do not have any negative effect. For a given weight, the microstructure of the invention is somewhat bulkier than for the unstructured film.

[0184] The microstructure inherently is significantly more stable and can be applied with greater precision.

TABLE-US-00001 TABLE 1 Sample Microstructured Flat A Stress 0.4 +/− 0.33 kPa 0 kPa sample Detachment 5.8 +/− 5.6 mJ/m.sup.2 0 mJ/m.sup.2 energy B Stress 1.13 +/− 0.9 kPa 0 kPa sample Detachment 16.9 +/− 17 mJ/m.sup.2 0 mJ/m.sup.2 energy C Stress 17 +/− 1.6 kPa 9.2 +/− 2.2 kPa sample Detachment 1003 +/− 196 mJ/m.sup.2 191 +/− 54 mJ/m.sup.2 energy

TABLE-US-00002 TABLE 2 Storage modulus E~3 * G′ [Pa] G′ [MPa] G′ Sylgard 184 10:1 41 400 1.24 G′ MDX4-4210 360 666  1.08 G′ MG7-1010 27 600 0.0828 G′ Sylgard 100:1.6   7673 0.023

TABLE-US-00003 TABLE 3 R.sub.z [μm] 0.10 1.97 49.66 A 100 80.7 2.50 A-Ref 100.00 56.2 0.00 B 100 66.5 5.23 B-Ref 100.00 62.9 0.00 C 100 79.9 32.70 C-Ref 100.00 67.4 4.80 B-OS (30 μm) 100 85.9 51.20 B-OS Ref (30 μm) 100.00 65.3 7.70 B-OS (70 μm) 100 83.77 51.30 B-OS Ref (70 μm) 100.00 67.2 12.20

TABLE-US-00004 TABLE 4 R.sub.z [μm] 0.10 1.97 49.66 A 5.44 4.39 0.14 A-Ref 53.50 30.06 0.00 B 11.85 7.88 0.62 B-Ref 49.07 30.84 0.00 C 32.8 26.21 10.74 C-Ref 91.46 61.64 4.38 B-OS (30 μm) 23.86 20.50 12.22 B-OS Ref (30 μm) 80.22 52.40 6.23 B-OS (70 μm) 18.12 15.18 9.30 B-OS Ref (70 μm) 79.66 53.55 9.73

REFERENCE SIGNS

[0185] 100 mold for microstructure (Elastosil 4601) [0186] 101 microstructure (Silastic MDX4-4210) [0187] 102 supporting layer (Silastic MDX4-4210) [0188] 103 layer (Silastic MDX4-4210) [0189] 104 adhesion layer (Dow Corning MG7-1010) [0190] 105 adhesion layer (Dow Corning MG7-1010) [0191] 106 adhesion layer (Dow Corning MG7-1010) [0192] 110 wafer [0193] 111 glass plate [0194] 112 plasma-activated glass plate [0195] 120 auxiliary layer [0196] 130 supporting layer [0197] 131 adhesion layer [0198] 132 adhesion layer [0199] 133 soiling [0200] 134 rough surface (skin) [0201] 135 release liner [0202] 140 load cell [0203] 141 strip [0204] 142 substrate [0205] 143 backing (glass) [0206] 144 hexapod