US-12617913-B2 - Reversible wrinkle patterns and methods of making and using the same

Abstract

The present disclosure relates to reversibly wrinkled silk-based compositions. The provided compositions are tunable and the reversible wrinkles are sensitive to water vapor, methanol vapor, and UV irradiation. The present disclosure also provides methods for making and using the same.

Inventors

• Fiorenzo G. Omenetto
• Yu Wang
• Beom Joon Kim

Assignees

• TRUSTEES OF TUFTS COLLEGE

Dates

Publication Date

20260505

Application Date

20200327

Claims (12)

1. 1 . An article of manufacture, comprising: a layered composition comprising a silk fibroin substrate in direct contact with a flexible polymer substrate, wherein the layered composition, following heating and cooling of the layered composition, exhibits reversible wrinkles on at least a portion of a surface of the silk fibroin substrate, and wherein at least some of the reversible wrinkles are reduced or erased following exposure to water vapor, methanol vapor, or ultra violet (UV) radiation.
2. 2 . The article of manufacture of claim 1 , wherein the silk fibroin substrate is or comprises amorphous silk fibroin.
3. 3 . The article of manufacture according to claim 1 , wherein the silk fibroin substrate is or comprises silk fibroin characterized by a presence of β-sheet formation.
4. 4 . The article of manufacture according to claim 1 , wherein the silk fibroin substrate and the flexible polymer substrate have different plane-strain moduli.
5. 5 . The article of manufacture according to claim 1 , wherein the flexible polymer substrate is or comprises polydimethylsiloxane (PDMS).
6. 6 . The article of manufacture according to claim 1 , wherein an extent of a change in reversible wrinkles is tunable with exposure time.
7. 7 . The article of manufacture according to claim 1 , wherein an extent of a change in reversible wrinkles is tunable with water vapor exposure time.
8. 8 . The article of manufacture according to claim 1 , wherein an extent of a change in reversible wrinkles is tunable with methanol vapor exposure time.
9. 9 . The article of manufacture according to claim 1 , wherein an extent of a change in reversible wrinkles is tunable with UV radiation exposure time.
10. 10 . The article of manufacture according to claim 1 , wherein the layered composition includes at least a portion of the silk fibroin substrate in a wrinkled state, wherein the wrinkled state is optically opaque.
11. 11 . The article of manufacture according to claim 1 , wherein the layered composition includes at least a portion of the silk fibroin substrate in a wrinkle-free state, wherein the wrinkle-free state is optically clear having a visible light transmittance from 70% to 95%.
12. 12 . The article of manufacture according to claim 1 , wherein at least a portion of the silk fibroin substrate exhibits structural color, and wherein the structural color is adjustable from a first structural color to a second structural color in response to the reversible wrinkles being reduced or erased following exposure to the water vapor, methanol vapor, or ultra violet (UV) radiation.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This patent application represents the U.S. national stage entry of International Application Ser. No. PCT/US2020/025386 filed on Mar. 27, 2020, which claims the benefit of priority of U.S. Provisional Application Ser. No. 62/824,962 filed on Mar. 27, 2019, entitled “Reversible Wrinkle Patterns and Methods of Making and Using the Same,” the contents of each of which are hereby incorporated by reference herein. STATEMENT REGARDING FEDERALLY FUNDED RESEARCH This invention was made with government support under grant N00014-16-1-2437 awarded by the United States Navy. The government has certain rights in the invention. BACKGROUND Protein micropatterning and nanopatterning have long provided sophisticated strategies for a wide range of applications including biointerfaces, tissue engineering, optics/photonics, and bioelectronics. In recent years, various micro- and nanofabrication technologies have been utilized to transform a water-based suspension of silk protein into all sorts of final material formats with periodic or aperiodic micro- or nanopatterns. However, the resulting patterned structures were stable, irreversible, and largely insensitive to external stimuli. Accordingly, there remains a need for improved methods of fabricating reversible, multi-responsive protein-based micropatterns using silk fibroin as the stimuli-responsive component. SUMMARY OF THE DISCLOSURE The present disclosure addresses the aforementioned drawbacks by providing reversibly wrinkled silk-based compositions. The provided compositions are tunable and the reversible wrinkles are sensitive to water vapor, methanol vapor, and UV irradiation. The present disclosure also provides methods for making and using the same. In one aspect, provided herein is an article of manufacture. The article of manufacture comprises or consists essentially of a layered composition comprising a silk fibroin substrate in direct contact with a flexible polymer substrate, where the layered composition, following heating and cooling of the layered composition, exhibits reversible wrinkles on at least a portion of a surface of the silk fibroin substrate, and wherein at least some of the reversible wrinkles are reduced or erased following exposure to water vapor, methanol vapor, or ultra violet (UV) radiation. The silk fibroin substrate can be or can comprise amorphous silk fibroin. The silk fibroin substrate can be or can comprise silk fibroin characterized by a presence of β-sheet formation. The silk fibroin substrate and the flexible polymer substrate can have different plane-strain moduli. The flexible polymer substrate can be or can comprise polydimethylsiloxane (PDMS). An extent of the change in reversible wrinkles can be tunable with exposure time. An extent of the change in reversible wrinkles can be tunable with water vapor exposure time. An extent of the change in reversible wrinkles can be tunable with methanol vapor exposure time. An extent of the change in reversible wrinkles can be tunable with UV radiation exposure time. In another aspect, provided herein is a method of producing a reversible wrinkled surface. The method can comprise or consist essentially of applying a silk fibroin solution to a flexible polymer substrate to form a bilayer structure comprising a silk fibroin layer and a flexible polymer layer; heating the bilayer structure, whereby the bilayer structure expands in response to heat stimulus; and cooling the heated bilayer structure to form a reversibly wrinkled surface on the silk fibroin layer. The method can further comprise exposing at least a portion of the wrinkled silk surface of the silk fibroin layer to methanol vapor, water vapor, or ultraviolet (UV) light to remove surface wrinkling from the exposed portion, thereby forming a patterned reversible wrinkled surface. One or more shadow masks can be used to selectively expose at least a portion of the reversibly wrinkled surface. The silk fibroin layer can comprise amorphous silk protein. The silk fibroin layer can comprise crystalline silk protein. The silk fibroin and the flexible polymer can have different plane-strain moduli. The flexible polymer substrate can comprise polydimethylsiloxane (PDMS). BRIEF DESCRIPTIONS OF THE DRAWINGS FIGS. 1a-1e demonstrate wrinkle patterns with different thicknesses of silk film. a, AFM images. The heating temperature used to form wrinkle is 140° C. b, Dependence of wavelength on the thickness of silk film. c, The wrinkle amplitude as a function of wavelength. Solid lines in (b) and (c) are the fitted lines of the experimental data. d, Transmittance spectra of the wrinkled structures with different thicknesses of silk film. e, Dependence of transmittance at λ=630 nm on the thickness of silk film. FIGS. 2a-2e demonstrate wrinkle patterns formed under different heating temperatures. a, AFM images. The thickness of silk film is fixed to 147 nm. b, Dependence of amplitude (black square) and wavelengt