Nanocoatings are making a significant impact in the electronics sector, driven by consumer requirements and the need to enhance the speed and performance of computing components, while reducing their size. Protection and conductivity are key areas for nanocoatings in electronics. Films and coatings incorporating silver nanowires, graphene, carbon nanotubes, quantum dots include transparent electrodes for touch screens, liquid crystal displays, e-paper and OLED devices, and thin film photovoltaics. Transparent conductive films (TCF) have been incorporated into sensors on touchscreen technologies and as protective coatings on consumer electronics. Nanocoatings are also being used to boost the efficiency with which heat can be removed from semiconductors and other devices and add anti-static and electromagnetic shielding properties.
Market drivers
The demand for TCFs is expected to grow rapidly as electronic devices, such as touch screens, displays, solid state lighting and photovoltaics, will become ubiquitous in our lives. Indium tin oxide (ITO) replacement is a key theme among product development.
ITO replacement: ITO is the dominant transparent conductor in the electronics market for touch screens. However it has certain limitations in applications for next-generation flexible display devices including:
• increasing price due to indium scarcity and processing requirements, which renders it difficult to use in low-cost, large-area electronics;
• ITO is mechanically rigid and can easily wear out or crack when used in applications where bending is involved. This renders it unsuitable for future flexible electronics applications.
Carbon nanotubes (CNTs) and graphene are leading candidates to replace ITO in current systems and in flexible electronics.
Anti-fingerprint: Touch screen devices are also routinely subjected to touch and thus commonly stained with undesirable fingerprint, skin oil, sweat and cosmetics. Anti-fingerprint nanocoatings are growing in demand as they provide material surfaces with self- cleaning, or easy-to-clean features that improve aesthetic appearance and save maintenance costs.
Waterproofing: Water is the main cause of lost function in electronic devices. Millions of mobile phones and many other devices are damaged by water annually. There is therefore a large opportunity to offer consumers protection for their electronics against water and moisture damage.
Performance benefits
The development of future flexible and transparent electronics relies on novel materials, which are mechanically flexible, lightweight and low-cost, in addition to being electrically conductive and optically transparent.
Nanocoatings have therefore emerged as an interesting alternative material system for electronics as they promise the high electronic performance of crystalline inorganic materials, and at the same time offer a low temperature processibility of organic materials. These unique attributes have opened up completely new possibilities for future thin film electronics.
Commercialization
Liquid repellent, thermal, conductive, magnetic and anti-corrosive nanocoatings have been applied inside and outside electronic devices, but to now have mainly been applied in specialist applications in the military, aerospace and automotive industries.
There are around 200 companies and research institu-tions currently developing ITO film alternatives such as metal meshes, silver nanowires, conductive polymers, carbon nanotubes, other 2-D materials and GaN. Quantum dot, nanoparticle silver, silver nanowires, graphene enabled consumer electronics products are on the market in 2014-2015.
A number of companies are now producing superhydrophobic nanoscale coatings for smartphones and tablets. As well as providing a direct barrier to moisture, these coatings are also used for anti-icing, anti corrosion, anti-fouling, and anti-microbial surfaces.
Liquipel, HzO and P2i are the main players in this market and their products coat Sony’s Xperia Tablet Z and the Motorola RAZR range.
