Coated Microstructured Film for Wavelength-Selective Light Control
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Solution Overview
Problem
Existing microstructured films lack the ability to achieve customizable wavelength-selectivity, particularly for small-volume applications, as they typically rely on light-absorbing pigments that may not provide the desired spectral properties.
Innovation Solution
A coated microstructured film is developed, featuring a plurality of microstructures with a coating comprising one or more polyelectrolytes. The coating is applied selectively, with a thicker layer on one portion of the microstructures and a thinner or absent layer on another portion, and is essentially free of light absorptive materials. This allows for the subsequent infusion of light absorptive materials or application of pigments to achieve desired wavelength-selectivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If light-absorbing pigments are used in microstructured films to achieve wavelength-selectivity, then wavelength-selectivity is improved, but visible light transmission deteriorates
Solution Approach 1:
The film is divided into multiple discrete microstructures (ribs and channels) that can be independently controlled. By selectively applying coating to specific portions of microstructures rather than uniformly across the entire film, the invention segments the light control function across different spatial regions, enabling wavelength-selectivity in certain areas while maintaining high transmission in others.
Solution Approach 2:
Different regions of the microstructured film are given different properties through selective coating application. The first portion of microstructures receives a coating that enables wavelength-selectivity, while the second portion remains uncoated or receives minimal coating to maintain high visible light transmission. This local differentiation resolves the contradiction by applying light-absorbing properties only where needed.
2Stability of the object's composition
If uniform coating is applied across all microstructures to achieve consistent optical properties, then optical uniformity is improved, but customization capability deteriorates
Solution Approach 1:
The coating application process is made dynamic and adjustable rather than fixed and uniform. The system allows for variable coating thickness and selective application to different portions of microstructures, enabling the same film structure to be customized for different applications by adjusting which portions receive coating and how thick the coating is applied.
Solution Approach 2:
The microstructured film design is universal in that it can serve multiple functions depending on coating application. The same underlying microstructure can be configured for high transmission, wavelength-selectivity, or intermediate properties by simply varying the coating application parameters, making the base structure multi-functional and highly adaptable.
3Adaptability or versatility
If light-absorbing materials are incorporated into the film structure to achieve wavelength-selectivity, then spectral control is improved, but manufacturing complexity deteriorates
Solution Approach 1:
The microstructured film is manufactured with the precise microstructure geometry and surface properties in advance, before the light-absorbing coating is applied. This preliminary preparation of the substrate simplifies the overall manufacturing process by separating the structural fabrication (which requires high precision) from the optical property customization (which can be done through simpler coating processes).
Solution Approach 2:
The coating layer acts as an intermediary between the microstructure and the light. Rather than incorporating light-absorbing materials directly into the microstructure fabrication process, the coating serves as a separate, adjustable layer that provides spectral control while leaving the microstructure manufacturing relatively simple and modular.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The coated microstructured film achieves a transmission of visible light of 75% or greater at a viewing angle of 0 degrees, while allowing for customizable light control and wavelength-selectivity by incorporating light absorptive materials, making it suitable for various applications including wearable sensors.
Implementation Method 1
The coating comprises one or more polyelectrolytes
Data Source
AI summary
The present disclosure provides a coated microstructured film (100a-c). The coated film includes microstructures (110) extending across a first surface of the microstructured film (100a-e) and a coating (130) on a first portion of at least some of the microstructures (110). The coating (130) includes one or more polyelectrolytes and has an average thickness T. A second portion of the coated microstructures either lacks the coating or has the coating with an average thickness of no more than 50% of T. The coating (130) is essentially free of any light absorptive material. A method of making the coated microstructured film (100a-c) is also provided. The method includes obtaining a microstructured film (100a), applying a coating (130) containing one or more polyelectrolytes to at least some of the microstructures (110), and removing at least some of the coating (130) from a second portion of the coated microstructures. Additionally, the present disclosure provides a method of making a light control film (110d. 100e). The method includes the above method as well as either infusing a light absorptive material into the coating of the coated microstructured film (100b-d) or applying a layer of a pigment on the coating. Such a light control film exhibits a transmission of visible light of 75% or greater at a viewing angle of 0 degrees.