Ripple Patterns Spontaneously Emerge through Sequential Wrinkling Interference in Polymer Bilayers

Pellegrino, Luca; Tan, Annabelle; Cabral, João T.

doi:10.1103/physrevlett.128.058001

Cited by 8 publications

(10 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[42][43][44][45] Multiaxial strain fields can induce a plethora of patterns; for instance 2D wrinkles can be fabricated, either through the simultaneous or sequential application of strain in two directions, yielding hexagonal, checkerboard, and herringbone wrinkled structures. [46][47][48] Sequential wrinkling approaches, [35,36] use surface wave superposition at varying angles (from 0° to 90°) to tune wrinkled surfaces from 1D to checkerboard, creating a variety of "s and ripple" structures, with additional in-plane (xy) periodicities. Representative topographies were designed and fabricated to yield desired optical effects detailed below.…”

Section: E Ementioning

confidence: 99%

“…The idea of directionality of wrinkle surfaces can be extended to that of 2D structures, where we can further manipulate the colors exhibited depending on the observer's perspective. As previously mentioned, 2D structures can be fabricated through either a simultaneous or sequential step, [35,36,46] where the sequential step can be performed at different angles. A symmetrical checkerboard was achieved through a sequential step performed at 90° with the conditions stated in the Experimental Section, achieving d = 680 nm.…”

Section: Homogeneity and Directional Colormentioning

confidence: 99%

“…We then quantify the joint roles of amplitude and periodicity in color brightness, and finally consider color modulation and directionality with gradient wrinkles (i.e., surfaces with spatially varying periodicity) and multi‐axial (bidirectional and isotropic) patterns that can be readily fabricated. We demonstrate both uniform and spatially varying colors with observation angle, and further expand the palette of pattern complexity by leveraging wrinkling wave superposition in both simultaneous and sequential steps, [ 35,36 ] to yield directional color resulting from the interference and relative orientation of wrinkling generations.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Tunable Structural Color with Gradient and Multiaxial Polydimethylsiloxane Wrinkling

Tan

Pellegrino

Ahmad

et al. 2022

Advanced Optical Materials

Self Cite

View full text Add to dashboard Cite

in dragonflies Rhyothemis resplendens. [20] Randomly oriented wrinkles were demonstrated to produce uniform bright structural colors with broad viewable angles, which can further be tunable using light sensitive polymers skins. [23] Mechanochromic response, that is, the change of color under stress, of wrinkled structures has been recently reported, employing various bilayer film structures. [22,24,25] The use of soft matter substrates, including elastomers, is advantageous as it readily allows optical properties to be tuned by the applied strain, by adjusting surface periodicity and amplitude, in addition to film thickness and mechanical modulus. Further, a wide range of surface patterns, including uniand multiaxial and hierarchical wrinkles, can be readily fabricated. Bilayers are generally fabricated by deposition or lamination of a thin and stiff film, typically a few 10-100 nm and GPa modulus, atop a thicker (mm) and softer (≈MPa), for instance an evaporated metal of a spun-coated glassy polymer supported by a polydimethylsiloxane (PDMS) elastomer. The mismatch in mechanical properties between films, provided that there is strong adhesion between them (to minimize delamination, crack formation, etc.), leads to surface buckling under strain. Strain can be induced thermally, by film evaporation/shrinkage, and commonly, by mechanical strain.Plasma oxidation provides a facile route to generating a thin, glass-like film onto PDMS, [26] enabling precise control of film thickness growth kinetics. [27][28][29] We have previously demonstrated the design of tunable optical gratings [30] using this method (building on the previous demonstrations with polymer bilayer laminates [31] ). The impact of the PDMS substrate thickness on the mechanochromic response of 1D plasma oxidized PDMS films has been recently reported, [32,33] and color tunability according to illumination and viewing angle examined. Recently, the incorporation of polystyrene nanoparticles and the use of wire-bar coating (yielding regular arrays) was demonstrated to produce both angle-independent and -dependent structural colors, upon plasma exposure and wrinkling. [34] In this study, we build upon the structural color and mechanochromic response exhibited by 1D plasma oxidized wrinkled PDMS topographies ranging from nano to the micronscale, and quantitatively examines the emergence of color mixing, by superposition of diffraction orders of distinct colors at similar observation angles. We then quantify the joint roles of amplitude and periodicity in color brightness, and finally consider The generation of structural color from wrinkled polydimethylsiloxane (PDMS) surfaces, fabricated by plasma exposure, subjected to uni-and multi-axial, and sequential strain fields is examined. The approach is based on the well-known, mechanically-induced, buckling instability of a supported bilayer, whereby the top glassy "skin" is formed by plasma oxidation. Surface periodicities 200 nm ≲ d ≲ 3 μm, encompassing the visible spectrum, are investigated in terms of the obs...

show abstract

Section: E Ementioning

confidence: 99%

Section: Homogeneity and Directional Colormentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Tunable Structural Color with Gradient and Multiaxial Polydimethylsiloxane Wrinkling

Tan

Pellegrino

Ahmad

et al. 2022

Advanced Optical Materials

Self Cite

View full text Add to dashboard Cite

show abstract

“…The resulting 2D pattern amplitude has been found to be reduced by a factor equal to the amplitude ratio A 2 /A 1 of the two generations. 58,67 Our data indicate that rodlike bacteria, with an intrinsic elongated shape, appear more efficiently constrained and directed by the wrinkling pattern, even when subjected to a lower amplitude. Spheroidal S. aureus, whose size is commensurate to the pattern scale, exhibits lower alignment on C surfaces, with a lower amplitude, compared to that on 1D patterns; therefore, additional correlation angles, beyond 0 and 90°, are observed.…”

Section: ■ Results and Discussionmentioning

confidence: 66%

Microbial Response to Micrometer-Scale Multiaxial Wrinkled Surfaces

Pellegrino

Kriem

Robles

et al. 2022

ACS Appl. Mater. Interfaces

Self Cite

View full text Add to dashboard Cite

We investigate the effect of micrometer-scale surface wrinkling on the attachment and proliferation of model bacteria (Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli K12) and fungi (Candida albicans). Specifically, sinusoidal (1D), checkerboard (C), and herringbone (H) patterns were fabricated by mechanical wrinkling of plasma-oxidized polydimethylsiloxane (PDMS) bilayers and contrasted with flat (F) surfaces. Microbial deformation and orientation were found to correlate with the aspect ratio and commensurably with surface pattern dimensions and local pattern order. Significantly, the proliferation of P. aeruginosa could be described by a linear scaling between bacterial area coverage and available surface area, defined as a fraction of the line integral along each profile with negative curvature. However, in the early stages of proliferation (up to 6 h examined), that C and H patterns disrupt the spatial arrangement of bacteria, impeding proliferation for several hours and reducing it (by ∼50%) thereafter. Our findings suggest a simple framework to rationalize the impact of micrometer-scale topography on microbial action and demonstrate that multiaxial patterning order provides an effective strategy to delay and frustrate the early stages of bacterial proliferation.

show abstract

“…Finally, building on our previous work, we explore the manipulation of structural colour in two-dimensional (2D) samples further [ 31 , 53 , 54 ]. 2D samples can either be fabricated in a sequential or simultaneous wrinkling step.…”

Section: Resultsmentioning

confidence: 99%

Multifaceted Structurally Coloured Materials: Diffraction and Total Internal Reflection (TIR) from Nanoscale Surface Wrinkling

et al. 2023

Self Cite

View full text Add to dashboard Cite

We investigate the combined effects of surface diffraction and total internal reflection (TIR) in the design of 3-dimensional materials exhibiting distinct structural colour on various facets. We employ mechanical wrinkling to introduce surface diffraction gratings (from the nano to the micron scales) on one face of an elastomeric rectangular parallelepiped-shaped slab and explore the roles, in the perceived colours, of wrinkling pattern, wavelength, the directionality of incident light and observation angles. We propose a simple model that satisfactorily accounts for all experimental observations. Employing polydimethylsiloxane (PDMS), which readily swells in the presence of various liquids and gases, we demonstrate that such multifaceted colours can respond to their environment. By coupling a right angle triangular prism with a surface grating, we demonstrate the straightforward fabrication of a so-called GRISM (GRating + prISM). Finally, using a range of examples, we outline possibilities for a predictive material design using multi-axial wrinkling patterns and more complex polyhedra.

show abstract

Ripple Patterns Spontaneously Emerge through Sequential Wrinkling Interference in Polymer Bilayers

Cited by 8 publications

References 37 publications

Tunable Structural Color with Gradient and Multiaxial Polydimethylsiloxane Wrinkling

Tunable Structural Color with Gradient and Multiaxial Polydimethylsiloxane Wrinkling

Microbial Response to Micrometer-Scale Multiaxial Wrinkled Surfaces

Multifaceted Structurally Coloured Materials: Diffraction and Total Internal Reflection (TIR) from Nanoscale Surface Wrinkling

Contact Info

Product

Resources

About