Method to suppress period doubling during manufacture of micro and nano scale wrinkled structures
OwnerSourabh Kumar Sahainventor
Life of this patent
Estimating the term…
Abstract
The range of stretch-tunability of sinusoidal wrinkled surfaces that are obtained by compression of supported thin films is limited by the emergence of a period-doubled mode at high compressive strains. This disclosure presents a method to suppress the emergence of the period-doubled mode at high strains. This is achieved by compressing pre-patterned supported thin films, wherein the pre-patterns are substantially similar to the natural pattern of the supported thin film system. As compared to flat thin film systems, pre-patterned thin film systems exhibit period doubling behavior at a higher compressive strain. The onset strain for emergence of period-doubling is tuned by altering the amplitude of the pre-patterns.
Claims20
A method of suppressing the phenomenon of period doubling at high strains during wrinkling of bilayers, comprising the steps of:
- providing a topographically patterned surface, wherein the topographic pattern is a sinusoidal periodic pattern and has a period that is substantially similar to the natural period of the bilayer;
- replicating the patterned surface onto a base substrate, thereby forming a non-flat pre-patterned surface on the base;
- stretching the pre-patterned base substrate beyond the nominal period doubling onset strain, thereby forming a stretched and pre-patterned base layer;
- generating a thin film on top of the stretched pre-patterned base layer, wherein the film conforms to the pre-patterned surface, thereby forming a composite pre-patterned material comprising a thin film on top of a stretched and pre-patterned base layer;
- partially releasing the stretch in the stretched pre-patterned base layer of the composite pre-patterned material, wherein the thin film buckles into the pre-patterned mode upon releasing the stretch, thereby leading to an increase in the amplitude of pre-patterns on the pre-patterned composite material;
- fully releasing the stretch in the stretched pre-patterned base layer of the composite material, wherein releasing the stretch leads to a further increase in the amplitude of the pre-patterns without emergence of a period that is different from that of the pre-pattern, thereby forming a high aspect ratio wrinkled surface with the same period as that of the pre-pattern.
A method of suppressing the phenomenon of period doubling at high strains during wrinkling of bilayers, comprising the steps of:
- providing a topographically patterned surface, wherein the topographic pattern is a sinusoidal periodic pattern and has a period that is substantially similar to the natural period of the bilayer;
- replicating the patterned surface onto a base substrate, thereby forming a non-flat pre-patterned surface on the base;
- stretching the pre-patterned base substrate along two different directions, wherein one stretch direction is aligned along the pre-pattern, and wherein the stretch along this aligned direction is higher than the nominal period doubling onset strain, thereby forming a stretched and pre-patterned base layer;
- generating a thin film on top of the stretched pre-patterned base layer, wherein the film conforms to the pre-patterned surface, thereby forming a composite pre-patterned material comprising a thin film on top of a stretched and pre-patterned base layer;
- releasing the stretch along the aligned direction, wherein releasing the stretch leads to an increase in the amplitude of the pre-patterns without emergence of a period that is different from that of the pre-pattern, thereby forming a high aspect ratio wrinkled surface with the same period as that of the pre-pattern;
- subsequently releasing the stretch along the second direction, wherein releasing the stretch leads to the thin film to buckle along the second direction, thereby forming a high aspect ratio biaxially wrinkled surface.
A method of suppressing the phenomenon of period doubling at high strains during wrinkling of bilayers, comprising the steps of:
- providing a topographically patterned surface, wherein the topographic pattern is a sinusoidal periodic pattern and has a period that is substantially similar to the natural period of the bilayer;
- replicating the patterned surface onto a base substrate, thereby forming a non-flat pre-patterned surface on the base;
- stretching the pre-patterned base substrate along two different directions, wherein one stretch direction is aligned along the pre-pattern, and wherein the stretch along this aligned direction is higher than the nominal period doubling onset strain, thereby forming a stretched and pre-patterned base layer;
- generating a thin film on top of the stretched pre-patterned base layer, wherein the film conforms to the pre-patterned surface, thereby forming a composite pre-patterned material comprising a thin film on top of a stretched and pre-patterned base layer;
- simultaneously releasing the stretch along both the directions, wherein releasing the stretch leads to the thin film to buckle along both the directions, and wherein releasing the stretch leads to an increase in the amplitude of the pre-patterns along one direction without emergence of a period that is different from that of the pre-pattern, thereby forming a high aspect ratio biaxially wrinkled surface.
Dependencies are inferred from the claim text.