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Controlled mud-crack patterning and self-organized cracking of polydimethylsiloxane elastomer surfaces.

Seghir R, Arscott S - Sci Rep (2015)

Bottom Line: The density of the mud-crack patterns depends on the plasma dose and on the metal thickness.The mud-crack patterning can be controlled depending on the thickness and shape of the metallization - ultimately leading to regularly spaced cracks and/or metal mesa structures.Such patterning of the cracks indicates a level of self-organization in the structuring and layout of the features - arrived at simply by imposing metallization boundaries in proximity to each other, separated by a distance of the order of the critical dimension of the pattern size apparent in the large surface mud-crack patterns.

View Article: PubMed Central - PubMed

Affiliation: Institut d'Electronique, de Microélectronique et de Nanotechnologie (IEMN), CNRS UMR8520, The University of Lille, Cité Scientifique, Avenue Poincaré, 59652 Villeneuve d'Ascq, France.

ABSTRACT
Exploiting pattern formation - such as that observed in nature - in the context of micro/nanotechnology could have great benefits if coupled with the traditional top-down lithographic approach. Here, we demonstrate an original and simple method to produce unique, localized and controllable self-organised patterns on elastomeric films. A thin, brittle silica-like crust is formed on the surface of polydimethylsiloxane (PDMS) using oxygen plasma. This crust is subsequently cracked via the deposition of a thin metal film - having residual tensile stress. The density of the mud-crack patterns depends on the plasma dose and on the metal thickness. The mud-crack patterning can be controlled depending on the thickness and shape of the metallization - ultimately leading to regularly spaced cracks and/or metal mesa structures. Such patterning of the cracks indicates a level of self-organization in the structuring and layout of the features - arrived at simply by imposing metallization boundaries in proximity to each other, separated by a distance of the order of the critical dimension of the pattern size apparent in the large surface mud-crack patterns.

No MeSH data available.


Related in: MedlinePlus

Modelling the mud-cracking of metallized, oxygen plasma-treated PDMS.(a) schematic diagram showing film having residual tensile stress  (top) and cracked film having crack width f (middle), and SEM image of a cracked PDMS/SiOx/Cr film – scale bar = 5 μm (bottom). (b) schematic diagram showing pre-cracked, virtual state (top) and cracked state (middle), and mechanical model of the multi-layer (bottom). (c) modelling of crack spacing-to-crack width ratio (λ/f) as a function of chromium thickness  and chromium stress level . Experimental values are shown as red circles for 5 nm, 10 nm and 100 nm thick chromium films. The dashed lines are explained in the text.
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f7: Modelling the mud-cracking of metallized, oxygen plasma-treated PDMS.(a) schematic diagram showing film having residual tensile stress (top) and cracked film having crack width f (middle), and SEM image of a cracked PDMS/SiOx/Cr film – scale bar = 5 μm (bottom). (b) schematic diagram showing pre-cracked, virtual state (top) and cracked state (middle), and mechanical model of the multi-layer (bottom). (c) modelling of crack spacing-to-crack width ratio (λ/f) as a function of chromium thickness and chromium stress level . Experimental values are shown as red circles for 5 nm, 10 nm and 100 nm thick chromium films. The dashed lines are explained in the text.

Mentions: In an effort to understand the cracking behaviour we develop here a simple analytical model to relate the cracking to the residual tensile stress in the layers. The details and assumptions of the model can be found in Section 6 of the Supplementary Information. We will now summarize the key elements of the model. The experimental results (see the SEM image in Fig. 7a) indicate cracking and delamination at the mesa boundaries. It is important to note that the SEM image indicates that the silica-like layer is also cracked and delaminated from the PDMS surface (not visible here) – this is in agreement with Yang et al.65 who demonstrated that the stiffness inside the cracks of plasma-oxidized PDMS is significantly less than on the non-cracked surface. This enables us to define two dimensions: λ (the characteristic mesa size) and f (the characteristic crack width) – see the schematic diagrams in Fig. 7a,b. In a first approximation the cracked layer can thus be considered to be a number of mesas composed of PDMS/SiOx/Cr tri-layers of size λ separated only by PDMS parts of size f.


Controlled mud-crack patterning and self-organized cracking of polydimethylsiloxane elastomer surfaces.

Seghir R, Arscott S - Sci Rep (2015)

Modelling the mud-cracking of metallized, oxygen plasma-treated PDMS.(a) schematic diagram showing film having residual tensile stress  (top) and cracked film having crack width f (middle), and SEM image of a cracked PDMS/SiOx/Cr film – scale bar = 5 μm (bottom). (b) schematic diagram showing pre-cracked, virtual state (top) and cracked state (middle), and mechanical model of the multi-layer (bottom). (c) modelling of crack spacing-to-crack width ratio (λ/f) as a function of chromium thickness  and chromium stress level . Experimental values are shown as red circles for 5 nm, 10 nm and 100 nm thick chromium films. The dashed lines are explained in the text.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4594096&req=5

f7: Modelling the mud-cracking of metallized, oxygen plasma-treated PDMS.(a) schematic diagram showing film having residual tensile stress (top) and cracked film having crack width f (middle), and SEM image of a cracked PDMS/SiOx/Cr film – scale bar = 5 μm (bottom). (b) schematic diagram showing pre-cracked, virtual state (top) and cracked state (middle), and mechanical model of the multi-layer (bottom). (c) modelling of crack spacing-to-crack width ratio (λ/f) as a function of chromium thickness and chromium stress level . Experimental values are shown as red circles for 5 nm, 10 nm and 100 nm thick chromium films. The dashed lines are explained in the text.
Mentions: In an effort to understand the cracking behaviour we develop here a simple analytical model to relate the cracking to the residual tensile stress in the layers. The details and assumptions of the model can be found in Section 6 of the Supplementary Information. We will now summarize the key elements of the model. The experimental results (see the SEM image in Fig. 7a) indicate cracking and delamination at the mesa boundaries. It is important to note that the SEM image indicates that the silica-like layer is also cracked and delaminated from the PDMS surface (not visible here) – this is in agreement with Yang et al.65 who demonstrated that the stiffness inside the cracks of plasma-oxidized PDMS is significantly less than on the non-cracked surface. This enables us to define two dimensions: λ (the characteristic mesa size) and f (the characteristic crack width) – see the schematic diagrams in Fig. 7a,b. In a first approximation the cracked layer can thus be considered to be a number of mesas composed of PDMS/SiOx/Cr tri-layers of size λ separated only by PDMS parts of size f.

Bottom Line: The density of the mud-crack patterns depends on the plasma dose and on the metal thickness.The mud-crack patterning can be controlled depending on the thickness and shape of the metallization - ultimately leading to regularly spaced cracks and/or metal mesa structures.Such patterning of the cracks indicates a level of self-organization in the structuring and layout of the features - arrived at simply by imposing metallization boundaries in proximity to each other, separated by a distance of the order of the critical dimension of the pattern size apparent in the large surface mud-crack patterns.

View Article: PubMed Central - PubMed

Affiliation: Institut d'Electronique, de Microélectronique et de Nanotechnologie (IEMN), CNRS UMR8520, The University of Lille, Cité Scientifique, Avenue Poincaré, 59652 Villeneuve d'Ascq, France.

ABSTRACT
Exploiting pattern formation - such as that observed in nature - in the context of micro/nanotechnology could have great benefits if coupled with the traditional top-down lithographic approach. Here, we demonstrate an original and simple method to produce unique, localized and controllable self-organised patterns on elastomeric films. A thin, brittle silica-like crust is formed on the surface of polydimethylsiloxane (PDMS) using oxygen plasma. This crust is subsequently cracked via the deposition of a thin metal film - having residual tensile stress. The density of the mud-crack patterns depends on the plasma dose and on the metal thickness. The mud-crack patterning can be controlled depending on the thickness and shape of the metallization - ultimately leading to regularly spaced cracks and/or metal mesa structures. Such patterning of the cracks indicates a level of self-organization in the structuring and layout of the features - arrived at simply by imposing metallization boundaries in proximity to each other, separated by a distance of the order of the critical dimension of the pattern size apparent in the large surface mud-crack patterns.

No MeSH data available.


Related in: MedlinePlus