Patent ID: 9668885
Date: 2017-06-06
CPC Classifications: A61F,Y10T

Claim:
1. A method of making an external covering for use with a mechanical device that provides the external surface of the device with an external skin layer, the method comprising the steps of: providing a mold having a cavity with a predetermined shape and at least one surface having a pattern selected as one from the group of a nano-funnel array, micro-funnel array, or combination thereof; inserting a film into the cavity of the mold, the film being comprised of a polymer composite with carbon nanotubes embedded therein and oriented such that the external skin layer exhibits a gradient in mechanical properties; wherein the film has a first side and a second side; the first side of the film being in contact with the patterned surface of the mold's cavity; applying one selected from the group of heat, vacuum, pressure, or a combination thereof to the cavity or the film to form the film into the predetermined shape and to induce the formation of superhydrophobic cone-shaped projections on the first side of the film; back-molding an internal bulk layer to be in contact with the second side of the film, thereby, forming the external covering; the internal bulk layer comprising a flexible material that can conform to the shape of the mechanical device and be fastened thereto; opening a gap in the mold and injecting an in-mold coating into the gap to form a coating on the first side of the film, the coating being cured, such that the coating exhibits the contour of the cone-shaped projections and does not cause planarization of the outer surface on the first side of the film; and cooling and removing the external covering from the mold; wherein the cone-shaped projections provide the external skin layer with superhydrophobicity, while the embedded carbon nanotubes provide the external skin layer with the ability to transmit heat and enhanced mechanical properties as compared to an external covering comprising the polymer composite film absent the embedded carbon nanotubes; the enhanced mechanical properties being defined as an anisotropic increase in Young's modulus, hardness, and scratch resistance, and an anisotropic decrease in polymer creep.