Nanostructures with anti-counterefeiting features and methods of fabricating the same
Embodiments of the invention relate to methods of anti-counterfeiting for nanostructures and nanostructured devices. Specifically we describe a method of embedding a coded micro- or nanopatterns in nanostructures fabricated using Near-field rolling mask lithography, where areas of such features can be embedded into a transparent cylindrical or conic frame, or fabricated on the surface of flexible film laminated on the surface of the frame. Alternatively, specific coded nanofeatures distribution can be created using modulation of intensity or wavelength of the light source along the width or length of such cylinder or cone, or modulation of flexible film thickness or contact pressure between the rotatable mask and a substrate.
1 . A method of fabricating nanostructures having anti-counterfeiting features comprising:
a) providing a substrate having a radiation-sensitive layer on said substrate surface;
b) providing a rotatable mask having a nanopattern on an exterior surface of said rotatable mask;
c) providing a coded micro- or nanopattern in addition to said nanopattern of said rotatable mask
d) contacting said nanopattern with said radiation-sensitive layer on said substrate surface;
e) distributing radiation through said nanopattern, while rotating said rotatable mask over said radiation-sensitive layer, whereby a 2 sets of images are created in said radiation-sensitive layer, one is a main nanostructure image, and a second a coded anti-counterfeiting image
2 . A method in accordance with claim 1 , wherein said rotatable mask consists of a transparent cylinder or cone frame, and a flexible film is laminated on said rotatable mask frame.
3 . A method in accordance with claim 2 , wherein said coded micro- or nanopattern is fabricated on a said transparent cylinder or cone frame.
4 . A method in accordance with claim 2 , wherein said coded micro- or nanopattern is fabricated on a said flexible film
5 . A method in accordance with claim 2 , wherein said coded micro- or nanopattern is a diffractive optical element
6 . A method in accordance with claim 2 , wherein said coded micro- or nanopattern is a missing nano features on the said main nanopattern
7 . A method of fabricating nanostructures having anti-counterfeiting features comprising:
a) providing a substrate having a radiation-sensitive layer on said substrate surface;
b) contacting said nanopattern with said radiation-sensitive layer on said substrate surface;
c) distributing radiation through said nanopattern, while rotating said rotatable mask over said radiation-sensitive layer,
8 . A method in accordance with claim 7 , wherein an intensity of such radiation is modulated along the width of said rotatable mask in accordance with a specific code
9 . A method in accordance with claim 7 , wherein a wavelength of such radiation is modulated along the width of said rotatable mask in accordance with a specific code
10 . A method in accordance with claim 7 , wherein a wavelength radiation is created using 2 or more light sources having different wavelength or intensity
11 . A method in accordance with claim 7 , wherein said rotatable mask consists of a transparent cylinder or cone frame, and a flexible film is laminated on said rotatable mask frame.
12 . A method in accordance with claim 11 , wherein said flexible film thickness is modulated along the mask widths or length in accordance with a specific code
13 . A method in accordance with claim 11 , wherein a contact pressure between said rotatable mask and a substrate is modulated during said rotating process in accordance with a specific code