Engineers from UCL Electrical and Electronic Engineering were trying to make LEDs from a new silicon oxide based material. However, the devices seemed to be unstable: they kept giving varying results. UCL PhD student, Adnan Mehonic was asked to look specifically at the material’s electrical properties. He discovered that the material wasn’t unstable at all, but flipped between various conducting and non-conducting states very predictably depending on the voltage previously applied.
Materials that change electrical resistance in response to an applied voltage are known as ‘memristors’, because they ‘remember’ this change to their properties even after the power is switched off. This can be exploited for use in resistive RAM (ReRAM) devices, leading to memory storage which holds more information while using orders of magnitude less energy and space than existing technologies.
The novel discovery has led to the first ReRAM devices which are made of pure silicon oxide – therefore suitable for incorporation into existing silicon chip designs – and can operate in ambient conditions rather than requiring a vacuum. Another interesting aspect of the UCL chip is that it could be made transparent: opening up potential uses in touchscreens and mobile devices.
UCL Business provided the team with commercialisation funding, and the device has been developed to the point of filing a patent. Discussions and research are ongoing with a number of leading semiconductor companies including Sematech, and it is hoped that a device will be developed from this work.
Dr Tony Kenyon, who led the team producing the device, said: “Our ReRAM memory chips need just a thousandth of the energy and are around a hundred times faster than standard Flash memory chips. The fact that these devices can operate in ambient conditions and have a continuously variable resistance opens up a huge range of potential applications.”
Just one example of how research at UCL Electronic and Electrical Engineering could change the world.