Inkjet coatings with novel properties
Coatings have long played an important role in protection against corrosion, friction and wear, as well as in adding aesthetic value via metallic or coloured finishes. Advanced electroceramics represent an emerging technology with exciting potential for application in sensors, fuel cells, superconductors and more due to their electrical, magnetic or dielectric properties. Penetration of electroceramics into the global marketplace has been limited by the lack of efficient and cost-effective large-scale processing technology. Scientists initiated the EU-funded project 'Efficient environmental-friendly electro-ceramics coating technology and synthesis' (EFECTS) to deliver just that with modified inkjet printing at ambient temperature using commercially available equipment. Scientists investigated four different materials for separate uses to determine processing potential with inkjet application. Superconducting yttrium barium copper oxide (YBCO) is widely used to coat conductors such as power cables and magnetic energy-storage devices. The consortium obtained coated conductors with best superconducting properties ever recorded for solution based processing and almost perfect growth of ceramic layers on the metal substrate. Inkjet printed yttria-stabilised zirconia (YSZ) electrolyte layers for solid oxide fuel cells (SOFCs) demonstrated performance comparable to or better than that of conventionally fabricated electrolytes. This makes it a great cost-effective alternative. A partner is now commercialising the fuel cell. YSZ layers for thermal barrier coatings have proved equally successful and are now being tested by the Greek aerospace industry for turbine protection. Titanium dioxide (TiO2) is well known for its hydrophilicity and use in self-cleaning surfaces. The photocatalytically active TiO2 coatings on glass exhibit similar performance to commercially available self-cleaning coatings. They can also be used on ceramic tiles and other surfaces. Lanthanum strontium manganate (LSMO) is used in magnetic nanoparticle (NP)-based inks for memories, sensors and more. Jettable LSMO inks compatible with high-resolution printing from computer-aided design/computer-aided manufacturing (CAD/CAM) systems have also been demonstrated. EFECTS has delivered low-cost, environmentally friendly and high-performance inks and printing technology to facilitate use of electroceramics in multi-functional coatings. Novel products have been commercialised by some partners, two patents were awarded and 14 papers have already been published with more in preparation.