MOULDED BODY COMPRISING A STRUCTURED SURFACE FOR CONTROLLED ADHESION

Abstract

A moulded body comprising includes a structured surface, wherein the surface has a structuring including a plurality of protrusions (pillars), at least each having a stem and comprising an end face pointing away from the surface. With this end face, the protrusions come into contact with the surface of the adhered object, wherein at least one protrusion comprises at least one structural feature, which, when loading the protrusion, leads to a directed deformation of the protrusion by changing the adhesion.

Claims

1. A shaped body having a structured surface whose structuring comprises a multiplicity of pillars each having at least one stem and at least one end face pointing away from the surface and at least one pillar comprises at least one structural feature, wherein the structural feature leads to directed deformation on loading of the pillar.

2. The shaped body as claimed in claim 1, wherein the at least one structural feature is a recess and/or bulge of the pillar relative to its basic shape.

3. The shaped body as claimed in claim 1, wherein the at least one structural feature is arranged on one side of the pillar.

4. The shaped body as claimed in claim 1, wherein at least one structural feature is a recess.

5. The shaped body as claimed in claim 1, wherein at least one structural feature comprises parts of the end face of the pillar.

6. The shaped body as claimed in claim 1, wherein at least one structural feature is a flexion.

7. The shaped body as claimed in claim 1, wherein the structural features are arranged on the individual pillars such that the lateral forces of the deformation cancel one another out.

8. The use of a shaped body as claimed in claim 1.

9. A shaped body, comprising: a structured surface comprising a multiplicity of pillars, each pillar having at least one stem and at least one end face pointing away from the surface, wherein at least one pillar comprises at least one structural feature that provides directed deformation on loading of the pillar.

10. A method, comprising: contacting a surface of an object with the shaped body as claimed in claim 1; and loading the at least one pillar comprising the at least one structural feature, thereby leading to a directed deformation of the at least one pillar with a change in adhesion.

Description

[0077] FIG. 1 shows micrographs (left) and three-dimensional representations (right) of the structures A2 and A2;

[0078] FIG. 2 shows micrographs (left) and three-dimensional representations (right) of the structures A3, A4 and A5;

[0079] FIG. 3 shows micrographs (left) and three-dimensional representations of the structures A6 and A7;

[0080] FIG. 4 shows micrographs (left) and three-dimensional representations of structures, 2×3 arrangement of the pillars;

[0081] FIG. 5 shows schematic representations of the reference structures A, B, C, D, E;

[0082] FIG. 6 shows schematic representations and cross sections of various structures with a notch (notch A to notch E);

[0083] FIG. 7 shows schematic representations and cross sections of various structures with one slot or two or more slots (slot A to slot E);

[0084] FIG. 8 shows schematic representations of various structures with a corner and a notch, and also a cross section through the corner structure (corner A to corner E);

[0085] FIG. 9 shows three-dimensional representation and cross section through a structure with curvature (S shape);

[0086] FIG. 10 shows schematic representation of structures with 6 columns, structures, reference F, notch F, corner F and S structure F;

[0087] FIG. 11 shows schematic representation of the parameters of the corners;

[0088] FIG. 12 shows schematic representation of the structures corner G, corner H, corner I, corner J, corner K and corner L;

[0089] FIG. 13 shows images of structures with Euler buckling;

[0090] FIG. 14 shows measurement of the adherence force (F.sub.H) for a compression of 25% as a function of a misorientation in x-direction for various samples;

[0091] FIG. 15 shows adhesion measurements on different samples a) 250 mN force measuring sensor, velocity: 100 μm/s; reference B and A1; b) 2 N force measuring sensor, velocity 5 μm/s; no hold time on contact with the substrate; compression force 500 μN;

[0092] FIG. 16 shows force-displacement diagram for structure A2 (a) and A1 (b) measured with 2N force measuring sensor, velocity 10 μm/s;

[0093] FIG. 17 shows measurement of the pressing force as a function of the distance for reference A, notch A, notch B, 250 mN force measuring sensor; velocity 100 μm/s;

[0094] FIG. 18 shows percentage decrease in the adhesion force of various structures (reference A and slotted structures) on compression of 15% (250 mN force measuring sensor, velocity 10 μm/s);

[0095] FIG. 19 shows adherence force profile as a function of the compression for the structure reference F;

[0096] FIG. 20 shows measuring series for the structure reference F for adherence force (F.sub.H), pressing force (F.sub.r) and standardized contact area at the transition from advance and removal (A/A.sub.0), 250 mN force measuring sensor, advancing and retreating velocity 10 μm/s, no hold times on contact, waiting time between each measurement 3 minutes;

[0097] FIG. 21 shows measuring series like FIG. 20 for the structure notch F;

[0098] FIG. 22 shows measuring series like FIG. 20 for the structure corner F;

[0099] FIG. 23 shows measuring series like FIG. 20 for the S structure F;

[0100] FIG. 24 shows force-displacement diagrams for the structures a) reference F, b) notch F for compressions of 10%, 25% and 45%;

[0101] FIG. 25 shows force-displacement diagrams for the structures a) corner F, b) S structure F for compressions of 10%, 25% and 45%;

[0102] FIG. 26 shows influence of the velocity on detachment on the adherence force for compressions of 10%, 25% and 45% a) reference F, b) notch F, 250 mN force measuring sensor, advancing velocity 10 μm/s, detachment velocity 5 μm/s-500 μm/s;

[0103] FIG. 27 shows influence of the velocity on detachment on the adherence force for compressions of 10%, 25% and 45% a) corner F, b) S structure F, 250 mN force measuring sensor, advancing velocity 10 μm/s, detachment velocity 5 μm/s-500 μm/s;

[0104] FIG. 28 shows measuring series relating to the dependency relationship between the corner angle according to table 9 and the adherence force (each first column: adherence force in the range of use; each second column: max. compression force; each third column: peel compression);

[0105] FIG. 29 shows measuring series relating to the dependency relationship between the corner dimension according to table 9 and the adherence force (each first column: adherence force in the range of use; each second column: max. compression force; each third column: peel compression);

PRODUCTION

[0106] The structures were produced in three steps. First the positive structures were produced by means of 2-photon polymerization (2PP), after which this structure was modeled using an elastomer (preferably silicone) to form a negative shape, and lastly an impression was taken from this negative shape of the positive structure, using a further elastomer (polyurethane or silicone).

[0107] 2-Photon Polymerization (2PP)

[0108] The surface of the substrates was activated in a plasma oven for 3 minutes. Then a silanization was performed with the reagent 3-(trimethoxysilyl)propyl methacrylate (MPTS), by placing a few drops of the reagent onto the substrate. After 60 minutes, the reagent was washed off with ethanol and the substrate was dried.

[0109] The structures were written using the Photonic Professional GT or GT2 (PPGT or PPGT2) from Nanoscribe. Writing took place using the Zeiss lenses 10×(NA 0.3), 25×(NA 0.8) and 63×(NA 1.4). Nanoscribe photoresists IP-S, IP-Dip, IP-Q, IP-G 780 were used. The substrates used were borosilicate glass, quartz glass (25×25×0.7) mm or glass coated with indium-tin oxide (ITO). The writing parameters were adapted so that the structures could be reproduced without defects and as exactly as possible.

[0110] For example, writing took place with a 25×(NA 0.8) lens with 26 mW laser power and a writing speed of 100,000 μm/s onto ITO-coated glass with IP-S. The structures were written in solid form, since the stability is needed for the impression in order to prevent the structures collapsing.

[0111] The structures produced using 2PP were developed in the solvent propylene glycol monomethyl ether acetate (1-methoxy-2-propyl acetate, MPA) until the unpolymerized photoresist dissolved. The MPA solvent was then replaced by isopropanol. Remaining in the isopropanol solvent, the written structure was post polymerized for 5 minutes under a nitrogen atmosphere with a UV lamp. The structure was subsequently removed cautiously from the isopropanol and rinsed.

[0112] Production of a Negative Shape

[0113] First of all the surface of the written structure was activated in a plasma oven for a minute. Subsequently a number of drops of the reagent (3,3,3-trifluoropropyl)trimethoxysilane were placed onto the structure and the substrate, and after 45 minutes were washed off with ethanol, and the structure was dried.

[0114] An impression was taken of the substrate using a silicon elastomer, as for example with Koraform A40 (from CHT Bezema) or Elastosil® M4601(from Wacker).

[0115] Production of the Positive Structures

[0116] The model may either be impressed directly onto a suitable substrate (e.g. a metal peg with which the structure is to be handled), to which it adheres as a result of the curing, or may be bonded adhesively to a holder only after curing has taken place. Materials used included, inter alia, polyurethane (PU) PMC-780 (from Smooth-On) with a Shore A hardness of 80, PMC-770 (from Smooth-On) with a Shore A hardness of 70, or silicones such as Sylgard 184 (Dow), Silopren® LSR 7060 (Momentive) or KER-4690 (Shin-Etsu). A small amount of the material was placed cautiously onto the corresponding mold. The mold was then covered accordingly under reduced pressure with a full filling. The structures obtained as impressions were characterized by microscope.

[0117] Structures Produced

[0118] Structures having different features for influencing the pillars were produced, in particular with notches, slots and flexions, but also the modification of the end face (contact area) with corners for a deliberate contact area changeover. An overview of the structures produced, with the corresponding dimensions, is given below.

[0119] Table 1 shows the dimensions of the various structures of type A1 to A7. FIGS. 1, 2 and 3 depict micrographs and three-dimensional representations of the various structures.

[0120] Table 2 reports the respective features of the individual structure.

[0121] Table 3 shows the dimensions and features of the structures from FIG. 4.

[0122] Table 4 shows the features of the reference structures produced, from FIG. 5.

[0123] Table 5 shows various structures with notches. Schematic representations and the cross section of the respective structure are shown by FIG. 6. A typical shape of a notch is a hemisphere having a radius of 14.4 μm (20% of the column diameter), 28.8 μm (40% of the column radius) or an oval notch radius. Typical positions of the notch are central, near to the contact area (end face) or near to the backing layer, preferably central, since it is there that the buckling takes place.

[0124] Table 6 shows various structures with slots. Schematic representation and the cross section of the respective structure are shown by FIG. 7. The typical cutting angle is 30°. The positions of the slot are central, near to the contact area (end face), near to the backing layer on both sides of the column. Customarily there may be 1 to 3 slots. They may be arranged on the inside and/or outside.

[0125] Table 7 and FIG. 8 show structures which have a corner on the end face, and also, as a further structural feature, have a notch. The cross section shown in FIG. 8 shows a cross section through the upper region with the corner. A typical corner angle is 45°. A typical corner dimension is 35% relative to the diameter of the end face without corner (35 μm for a diameter of 100 μm).

[0126] FIG. 9 shows a structure produced of the S type. A typical radius of the flexion is around 134 μm, corresponding to almost half the column height. The figures in the cross section correspond to millimeters.

[0127] FIG. 10 shows structures each having six columns. The circle diameter on which the center points of the outer columns lie is 300 μm in each case. The dimensions are shown in table 8.

[0128] FIG. 11 shows the definition of the parameters of the different corners (parameters in table 9) for structures based on corner F.

[0129] FIG. 12 shows the parameters and schematic representations of the structures corner G to L (parameters in table 9).

[0130] Table 10 shows the buckling behavior of different structures. The reference structures A to D always buckle outward or entirely. The results show that the features of the structures influence the buckling behavior, in particular the buckling direction (e.g., internal or external, or centrically inward or outward). Only if the slots are very close on the contact area (slot D) does the structure not buckle outward. In the case of the structures having two or more different features (corner inside, notch inside), the corner dominates the buckling behavior in the case of structures A to C. Only in the case of the notch with larger diameter (D) or oval notch (E) does the notch dominate the buckling behavior. This shows that the radius of the notch determines its influence. With slots in the vicinity of the contact area it might be possible to increase the adaptability of the structures to irregular surfaces.

[0131] FIG. 13 shows images of various structures on buckling. The reference to structure A buckles unpredictably. The direction is determined by influencing factors such as orientation of the structures to the substrate and quality of the structure. The notch structure A deliberately buckles outward relative to the center point of the structure. This reduces the contact area of the end face that is available for adhesion. The notch structure B with the larger notch radius buckles to an ever greater extent. This reduces the contact area to an even greater extent.

[0132] The adhesion is weakened to an even greater extent. The S structure A buckles outward in accordance with the predefined shape.

[0133] The buckling behavior of the notch structures with offset caps (inside or outside) is always dominated by the notch.

[0134] The 2×3 structures as well buckle selectively outward in accordance with their arrangement of the notches.

[0135] For the structures F, the influence of a tilting in x-direction on the adherence force and the buckling behavior was measured. For all structures, the adherence force decreases up to a tilting angle of 3°. The structure reference F buckles entirely in one direction in accordance with the tilt direction. The other structures (notch F, corner F and S structure F) always buckle centrically outward. The decrease in the adherence force is smaller in the case of the notch structure than in the case of the other structures (FIG. 14; adherence force (F.sub.H), compression force (F.sub.r)).

[0136] FIG. 15 shows the influence of the curvature of the S structure A1 on the adhesion force (FIG. 15 a) and b)). For the same contact area, lower adhesion forces are measured with the bent structures (A1) for a comparable pressing force. This is advantageous for the detachment of lightweight components.

[0137] From FIG. 16 it is evident that the structure A2 has an altered force-displacement profile in comparison to the structure A1. With the structure A1 there is no drop in force (drop in the pressing force) through buckling of the columns.

[0138] Similar results were measured for the structures from FIG. 4. The adhesion force is still constant even after 10 cycles. Moreover, the adhesion force also rises with increasing detachment velocity, provided no buckling has as yet been obtained in the structures.

[0139] FIG. 17 shows the influence of the notch radius on the pressing force. With increasing notch radius, the columns buckle earlier and the maximum pressing force is reduced. This is an advantage for automated operations, which are consequently not required to be advanced as precisely up to sensitive components.

[0140] FIG. 18 shows the reduction in the adhesion force at 15% compression (visual buckling, but no loss of contact area). Hence the adhesion force can be lowered by 20-50% for a pressing force of 5 mN, but only around 15% in the case of reference A (FIG. 18). The adhesion force increases by 30-40% with increasing detachment velocity (5-100 μm/s). In the non-buckled state, the hold time (0-10 seconds) has no influence on the adhesion force. At 15% compression, the hold time (0-10 seconds) likewise has no influence on the adhesion force.

[0141] FIG. 19 shows a typical adherence force profile as a function of the compression. With increasing compression, there is an upper plateau, a drop in force, a lower plateau and a further drop in force apparent. Particularly preferred are structures having a compression of 25% for a reduced adherence force. This allows the detachment even of sensitive objects. The first plateau is an effect of the buckling. With the second plateau the columns are strongly viscoelastically deformed, and so on removal the contact area can no longer be brought completely into contact and, as a result, the adherence force is reduced.

[0142] FIG. 20 shows a measuring series for the determination of the adherence forces at different pressing force (2.5% compression to 45% compression) for structure reference F. For each compression, a new measurement was carried out, and for this the adherence force F.sub.H, the pressing force F.sub.P and the contact area at the transition between advancing and removal were evaluated. Here, F.sub.H,Pt stands for the adherence force at a compression of 25%; F.sub.H,max for the maximum adherence force, and K for a compression.

[0143] Visual buckling occurs at z.sub.1≈7.5% and reduction of the contact area by peeling of the structure occurs at z.sub.2≈18.75%. The maximum possible compression force is F.sub.P,max≈33.3 mN and is attained at a compression of K(F.sub.P,max)≈19.25%. The maximum adherence force is F.sub.H,max≈13.3 mN and is attained at a compression of K(F.sub.H,max)≈12.5%. The contact area decreases as a result of the buckling and peeling by a maximum of 77.6% (A.sub.min≈22.4%). On a percentage basis, the adherence force can be lowered by the buckling to F.sub.H,min=44% relative to the maximum adherence force.

[0144] FIG. 21 shows a measuring series for the determination of the adherence forces at different pressing forces (2.5% compression to 45% compression) for structure notch F. For each compression, a new measurement was carried out, and for this the adherence force F.sub.H, the pressing force F.sub.P and the contact area at the transition between advancing and removal were evaluated.

[0145] Visual buckling occurs at z.sub.1≈9.25%. Start of peeling occurs at z.sub.2≈18.5%. The maximum compression force is F.sub.P,max≈27.6 mN and is attained at a compression of K(F.sub.P,max)≈19.0%. The maximum adherence force is F.sub.H, max≈10.8 mN and is attained at a compression of K(F.sub.H, max)≈6.25%. The contact area decreases as a result of the buckling and peeling by a maximum of 81.7% (A.sub.min≈18.3%). On a percentage basis, the adherence force can be lowered by the buckling to F.sub.H,min=45.8% relative to the maximum adherence force.

[0146] In comparison to the reference structure, no earlier buckling was observed. Reduced compression forces and reduced adherence forces were measured.

[0147] FIG. 22 shows a measuring series for the determination of the adherence forces at different pressing force (2.5% compression to 45% compression) for structure corner F. For each compression, a new measurement was carried out, and for this the adherence force F.sub.H, the pressing force F.sub.P and the contact area at the transition between advancing and removal were evaluated.

[0148] Visual buckling occurs at z.sub.1≈4.75%. Start of peeling occurs at z.sub.2≈12.5%. The maximum possible compression force is F.sub.P,max≈21.9 mN and occurs at a compression of K(F.sub.P,max)≈15.75%. The maximum adherence force is F.sub.H,max≈6.1 mN and occurs at a compression of K(F.sub.H,max)≈11.75%. On a percentage basis, the adherence force can be lowered by the buckling to F.sub.H,min=54.2%. The contact areas switch in a compression range from Z.sub.KFW,A≈13.0% to z.sub.KFW,Ω≈22.5%. The contact area decreases by a maximum of 48.1% (A.sub.min≈51.9%).

[0149] The structure buckles early. Compression force in the range of use is reduced by around 35%. The adherence force in the range of use is reduced by around 50%.

[0150] FIG. 23 shows a measuring series for the determination of the adherence forces at different pressing forces (2.5% compression to 45% compression) for S structure F. For each compression, a new measurement was carried out, and for this the adherence force F.sub.H, the pressing force F.sub.P and the contact area at the transition between advancing and removal were evaluated.

[0151] Visual buckling occurs at a compression of K(z.sub.1) 3.75%. Start of peeling occurs at a compression of K (z.sub.2) 10.5%. The maximum compression force is F.sub.P,max≈14.3 mN and occurs at a compression of K(F.sub.P,max)≈22.5%. The maximum adherence force is F.sub.H,max 8.8 mN and is attained at a compression of K(F.sub.H,max)≈10.0%. The contact area decreases by a maximum of 81% (A.sub.min≈19.0%). On a percentage basis, the adherence force can be lowered to F.sub.H,min=4.5% of the maximum adherence force.

[0152] In comparison to the reference structure, the structure buckles early. The compression force is reduced in the range of use by around 55%. The adherenece force in the range of use is reduced by around 40%.

[0153] FIGS. 24 and 25 show force-displacement diagrams for various structures.

[0154] FIGS. 26 and 27 show the dependency relationship between the adherence force and the detachment velocity.

[0155] FIG. 28 shows a measuring series in which the corner angle of a structure was varied from 15° to 60°. The corner dimension was kept constant (table 9). Large corner angles are the most advantageous, since in this case the buckling begins at the lowest compressions, the maximum compression force is the lowest, and the adherence force drops the greatest. The best structure from this measuring series, structure I, however, does not exhibit any massive improvement in comparison to the structure F.

[0156] FIG. 29 shows a measuring series in which the corner dimension of a structure was varied from 25 μm to 55 μm. The corner angle was kept constant (table 9). Corner dimensions in the range of 35-45% of the pillar diameter are the most advantageous, since here the buckling begins at the lowest compressions, the maximum compression force is the lowest, and the adherence force drops the greatest. The best structure from this measuring series, structure K, again shows an improvement in comparison to the structure F.

TABLE-US-00001 TABLE 1 A1 A2 A3 A4 A5 A6 A7 Type (FIG. 1) (FIG. 1) (FIG. 2) (FIG. 2) (FIG. 2) (FIG. 3) (FIG. 3) Diameter of 1000 1000 1000 1000 1000 1000 1000 Backing Layer 1 [μm] Thickness of 100 100 100 100 100 100 100 Backing Layer 1 [μm] Diameter of 300 300 300 300 300 300 300 Backing Layer 2 [μm] Thickness of 50 50 50 50 50 50 50 Backing Layer 2 [μm] Height of 288 288 288 288 288 288 288 column [μm] Diameter of 72 72 72 72 72 72 72 column [μm] Diameter of 90 90 90 90 90 90 90 caps [μm]

TABLE-US-00002 TABLE 2 A1 A2 A3 A4 A5 A6 A7 Type (FIG. 1) (FIG. 1) (FIG. 2) (FIG. 2) (FIG. 2) (FIG. 3) (FIG. 3) Feature Protrusion Notching Notching Notching Notching Notching Notching at at at at at at at half half half half half half half column height height height; height; height; height; height oriented inside; Caps Caps Caps Caps inward; Caps offset offset offset offset Caps offset outward inward outward outward offset inward outward

TABLE-US-00003 TABLE 3 2 × 3 with notches 2 × 3 without notches Type (FIG. 4) (FIG. 4) Diameter of round 1000 1000 backing layer [μm] Thickness of round 100 100 backing layer 1 [μm] Length of rectangular 320 320 backing layer [μm] Width of rectangular 570 570 backing layer [μm] Thickness of 50 50 rectangular backing layer [μm] Height of column 307.2 307.2 Diameter of column 76.8 76.8 Diameter of caps 96 96 Feature Notching at half height — with a diameter of 15.36 μm

TABLE-US-00004 TABLE 4 Reference A B C D E structure (FIG. 5) (FIG. 5) (FIG. 5) (FIG. 5) (FIG. 5) Structure 3 col- 5 col- 3 col- 5 col- 3 col- umns umns umns umns umns Diameter of 1000 1000 1000 1000 1000 Backing Layer 1 [μm] Thickness of 100 100 100 100 100 Backing Layer 1 [μm] Diameter of 300 300 300 300 300 Backing Layer 2 [μm] Thickness of 50 50 50 50 50 Backing Layer 2 [μm] Height of 288 288 288 288 288 column [μm] Diameter of 72 72 72 72 72 column [μm] Diameter of 90 90 — — — caps [μm] Feature — — — — With 45° corner

TABLE-US-00005 TABLE 5 Notch (notch A B C D E structure) (FIG. 6) (FIG. 6) (FIG. 6) (FIG. 6) (FIG. 6) Dimensions A A A A A according to reference structure Notch Diameter Oval Diameter Diameter Diameter 14.4 μm notch 28.8 μm 14.4 μm 14.4 μm Notch Central Central Central Near Near position contact Backing area Layer

TABLE-US-00006 TABLE 6 A B C D E Slot (FIG. 7) (FIG. 7) (FIG. 7) (FIG. 7) (FIG. 7) Dimensions A A A A A according to reference structure Number of 2 3 1 1 1 slots Slot opening 30° 30° 30° 30° 30° angle Slot Central, Central, Central, Near Near position inside inside inside contact contact area, area, inside inside and outside

TABLE-US-00007 TABLE 7 Corner inside, A B C D E Notch inside (FIG. 8) (FIG. 8) (FIG. 8) (FIG. 8) (FIG. 8) Dimensions A D E B C according to notch structure Corner angle 45° 45° 45° 45° 45°

TABLE-US-00008 TABLE 8 Reference Notch S-Structure Corner F F F F Type (FIG. 10) (FIG. 10) (FIG. 10) (FIG. 10) Columns 6 6 6 6 Diameter of 1000 1000 1000 1000 Backing Layer 1 [μm] Thickness of 100 100 100 100 Backing Layer 1 [μm] Diameter of 500 500 500 500 Backing Layer 2 [μm] Thickness of 50 50 50 50 Backing Layer 2 [μm] Height of 400 400 400 400 column [μm] Diameter of 100 100 100 100 column [μm] Diameter of — — — — caps [μm] Feature — Notch at upper S shape Corner ⅓ near to angle contact area; 45° notch radius: 15 μm

TABLE-US-00009 TABLE 9 Cor- Cor- Cor- Cor- Cor- Cor- Cor- ner F ner G ner H ner I ner J ner K ner L e [μm] 35 35 35 35 25 45 55 φ [°] 45 15 30 60 45 45 45

TABLE-US-00010 TABLE 10 Reference Reference Reference Reference Reference Structure A B C D E Behavior Outside Outside Outside Outside Buckles or entire or entire or entire or entire inward Structure Notch A Notch B Notch C Notch D Notch E Behavior Outside Outside Outside Outside Outside Structure Slot A Slot B Slot C Slot D Slot E Behavior Outside Outside Outside Inside Outside Structure Corner Corner Corner Corner Corner inside, inside, inside, inside, inside, notch notch notch notch notch inside A inside B inside C inside D inside E Behavior Inside Inside Inside Outside Outside