Research led by Professor Kourosh Kalantar-zadeh and Dr Torben Daeneke, based at RMIT University’s node of the ARC Centre of Excellence in Future Low-Energy Electronics Technology (FLEET) has developed a breakthrough method for creating ultra-thin metal oxide sheets, which have wide applications in today’s electronic and optical devices.

The novel and extraordinarily simple process developed by the researchers uses non-toxic liquid alloys of gallium as a reaction medium. The oxide layer forms on the surface of liquid gallium, which can then be removed in large quantities either by printing processes or by injecting air into the liquid metal, collecting the metal oxides from the bubble surfaces into naturally formed ultra-thin sheets.

The process is scalable, and does not require complex techniques currently in use by industry to create ultra-thin metal oxide sheets. In fact, the researchers describe the process as simple enough to be performed on a kitchen stove.

As well as greatly simplifying the creation of thin metal oxides, and so making them more widely available to electronics manufacturers, the process also has implications for catalysis, which is the basis of the modern chemical industry, with the potential to reshape how medicines, fertilisers and plastics are made.

Image: This image of a liquid metal ‘slug’ and its clear atom-thick ‘trail’ shows the breakthrough in action. When dissolved in a liquid metal core, certain metals leave behind this clear layer of their oxide, which is no thicker than a few atoms and can be peeled away by touching or rolling.
Image credit: RMIT University.