New 'metamaterial' could create ultra-sensitive sensors and faster electronics

A new “metamaterial” with properties not found in nature could help create ultra-sensitive sensors and high-speed electronics, researchers have claimed.

The team at King’s College London engineered a nanoscale device with the material, made of liquid metal eutectic gallium indium and gold nanorods separated by an air gap less than a nanometre across. When a voltage is applied, a stream of “hot electrons” with very high kinetic energy flows between the two sides.

These consistent and controllable electrons could be useful in high-energy techniques for synthesising new chemicals, the researchers said. The process, demonstrated with oxidisation and reduction reactions involving oxygen and hydrogen, also changes the flow of electrons. This change affects the flow of current and the emission of light, meaning operators could closely and sensitively monitor reactions.  

The material’s sensitivity could be useful in detecting hydrogen leaks from fuel cells or monitoring the presence of oxygen, the team said, although it could be modified to react to different molecules.

Future research could also exploit the light generated by the material by rapidly turning the voltage on and off to optically transmit information between or within microchips. The material’s tiny scale could replace semiconductors in electronic devices, the King’s scientists said, potentially aiding the development of faster electronics.