One of the most important uses for gold in industry is its use in electronics. In electronics, gold is valued for its thermal resistance, electrical conductance, and its corrosion-resistance. Gold makes electronic components highly reliable and is used in soldered joints, relay contacts, connecting wires, and connection strips. Solid-state electronics use low- voltage and low-current circuits which can be impeded by corrosion at its contact points. It is important that contact points remain corrosion-free so that the currents in electronics can operate correctly.
In all sophisticated electronic devices, a small amount of gold is used. This includes cell phones, electronic tablets, global positioning system (GPS) units, calculators, personal digital assistants, televisions, large electronic appliances, and other types of electronics. Each cell phone produced only uses roughly fifty cents worth of gold. Although this may not seem like much, one billion cell phones produced each year and each having a lifespan of about two years, their enormous numbers translate to a colossal amount of unrecycled gold being used.
Visual display technologies such as touchscreens use indium tin oxide (ITO). The continued use of ITO in touchscreens translates to high demand for ITO and will continue to be in demand as touchscreen technologies proliferate. ITO is valued for its use as a transparent conductor and more than 90% of touchscreen displays use ITO, however it is not the only transparent conductor. Gold and silver may not be the first thing that comes to mind for materials that are transparent but according to Professor Dimos Poulikakos at ETH Zurich, gold and silver are both choice materials for transparent conductors. ITO is used since it has a high degree of transparency and can be produced in thin layers, but it is only moderately conductive. To resolve conflicting objectives between high-conductivity and transparency made from gold and silver, the team at ETH Zurich created electrode metal grid walls of gold or silver of 80-500nm thick using 3D printing technology. This technology realizes high conductivity and a strong degree of transparency.
The nanowalls are created using a 3D printing process called NanoDrip that uses inks made of gold and silver nanoparticles in a solvent. The process uses an electric field to draw out ultra-small droplets of the metallic ink from the capillary and as the ultra-small droplets evaporate, structures of the metal grid arc built drop by drop. This new system has several advantages over ITO systems including greater cost efficiency, flexibility and it doesn't require a clean room environment as is required for ITO electrodes. Furthermore, the height of the electrodes can be scaled to allow for greater conductivity that is necessary for larger touchscreen, as well as producing faster and more accurate smaller touchscreens.
Gold is also used for advanced data storage. Scientists from China and Australia have created a new type high-capacity optical disk that can securely hold data for more than 600 years. The technology offers a compelling solution to the global data problem and offers more cost- efficient data storage. Big Data and cloud storage consume about 3% of the world's electricity and largely rely on hard disk drives that have a limited capacity of only 2TB per disk and a limited lifespan of about two years. The technology demonstrated by scientists at RMIT University in Melbourne, Australia and wuhan Institute of Technology in China, has the capacity to store four times as much as traditional optical disk drives-up to 10TB of storage-and with a lifespan of six centuries. Furthermore, the technology could greatly improve the energy efficiency of data storage centers, using 100p times less power than traditional hard disk data centers which require massive cooling and data migration tasks every two years.
The optical disks that RMIT and Wuhan scientists have created are far more superior than other optical disks and much more secure than hard disks. The technique for developing these optical disks combines gold nanomaterials with a hybrid glass material that has outstanding mechanic strength and is also suitable for mass production. The synthesis of nano-plasmodic hybrid glass composites through sintering-free incorporation of gold nanorods allow for data to be recorded in five dimensicthree dimensions of space plus polarization and color.
Scientific opportunities for new discoveries rely on storing large amounts of information to be collected and analysed. The information scientists collect also needs io be stored long-term in order for it to benefit humanity and later generations down the road. Ambitious scientific projects such as the Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Initiative is handling data measured in yottabytes, or one trillion terabytes to map the human brain and needs sufficient storage solutions. It also takes about 8 terabytes of data to study and analyse a genetic mutation in just one family tree. Another project that requires mass data storage is the Square Kilometre Array (SKA) radio telescope which produces 576 petabytes of raw data per hour. These types of projects are just a few examples of why gold-based advanced storage solutions will proliferate and how it will benefit humanity.
In 2017, the electronics sector used 265 tonnes of gold, a 4% increase on 2016 and the first year-on-year percentage growth since 2010.