Taking Inspiration from Nature
Currently, there is a need for improved materials which can overcome traditional problems faced by device design in areas like flat screen panels. Materials that mimic natural structures have been the focus of research in many industries, such as biomedicine, robotics, and wearable tech.
One such organic structure which can provide flat panel displays with enhanced functionality is the eye of a moth. Moths are nocturnal insects, and as such, have evolved eye structures that help them see in low light levels. This allows them to evade predators and find food.
On the surface of the eye, microscopic bumps uniformly arranged into rows give this organic structure the ability to take in small amounts of light without reflecting it. Each bump is smaller in size than visible light wavelengths. Their curved, spindle-shaped structure allows them to absorb incident light from multiple angles. The refractive index can continuously change, meaning that almost no light is reflected.
Effectively imitating this natural structure provides innovative coverings for flat display panels, touchscreen interfaces, mobile phone lenses, PDAs, and electroluminescent lamps which are both anti-reflective and anti-glare. This ability helps to overcome conventional issues with light flare and iridescence faced by these devices.
Anti Reflective Vs. Anti Glare
Anti-reflective and anti glare coatings are similar, but there are some key differences between the two. Anti-glare coatings reduce the impact of external sources of light by roughening the surface of the display, converting specular reflection into diffuse reflection. Etching and dip-coating methods can be used to prepare these coatings. However, due to the roughness of these coatings, an anti-fingerprint film is generally applied.
Anti-reflective coatings take into account both external and internal light sources that impact readability by reducing the amount of light transmitted through the display. Cumulative reflections can cause an image to become “washed-out” and therefore largely unreadable. These coatings achieve destructive interference in reflected light and enhance the incidence of transmitted light.
Constructing films for flat display screens and other key optical device components which possess both anti-glare and anti-reflective properties are therefore central to improving the quality of image output and readability, especially in environments with high levels of ambient light or sunlight.
MothEye Anti Reflective Anti Glare Films
MothEye Anti Reflective Anti Glare (MARAG) films are a novel and innovative type of biomimicking anti glare films and anti reflective coating material for use in applications such as flat panel displays and mobile phones. Incredibly durable, they reflect virtually no visible light, improving their use in environmental conditions such as bright sunlight.
The Autoflex MARAG (MothEye Anti-Reflective Anti-Glare) film was developed by UK manufacturers Autoflex and the Fraunholer Institute for Solar Energy, Germany.
The material has a hard coat finish and is tough and durable, resistant to scratches and fingerprints. Less than 1% of visible light is reflected by this material. Moreover, it possesses an exceptional level of optical clarity.
Companies such as Dexerials and Molex have also developed anti-reflective and anti-glare coatings in recent years based on the structure of moth eyes. In Dexerials’ material, resin bumps are formed which are smaller than visible light wavelengths.
The technology used by Dexerials to manufacture these films is the same as that used in Blu-ray discs. Pits are formed on a rolled master disc which correspond to the moth-eye structures using a method known as laser lithography. Nanoimprinting is then used to transfer the structures to films, and the entire process is precisely controlled by advanced software, which allows intimate control of microstructural patterns.
Another key benefit of Dexerials’ product is its anti-fogging capabilities, and it can easily be wiped clean. Aside from imparting electronic displays with enhanced anti-reflective and anti-glare capabilities, Dexerials’ film can be used in medical shields.
Benefits of MARAG Films
There are a number of key benefits with MARAG films for applications such as displays, optics, and so forth. These include mitigating problems such as cracking on flexible surfaces, low manufacturing costs, creating A/R layers which retain properties over a wide array of angles, and eliminating the need for complex, multi-layered coatings.
In Summary
MARAG films represent a next-generation, innovative solution to common problems in the fields of displays, optics, and associated application areas. Durable, easy to manufacture, cost-effective, and with high-performance capabilities, these moth-eye inspired film coatings offer enhanced read clarity compared to other materials, even in direct sunlight.
More from AZoM: Biomimetic Imprinted Polymers - A Guide to Their Possible Applications
Further Reading
Microcontinuum (website) Moth-eye Anti-Reflective Surfaces [online] Microcontinuum.com. Available at:
https://microcontinuum.com/nanofabrication-technology/moth-eye-ar-surfaces
Dexerials (2022) Moth-Eye Structures: The Ultimate Anti-Reflection Technology [online] techtimes.dexerials.com. Available at:
https://techtimes.dexerials.jp/en/optics/moth-eyes-type-anti-reflection/
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