Researchers at the University of Turku are developing microscopic memory resistors, memristors, that mimic brain activity, which could be the key to the growth in electricity consumption driven by artificial intelligence. A technology developed in Turku won two Finnish invention prizes this autumn.
A memristor is so small that it is invisible to the naked eye, but it could help solve a major global problem in the future.
Professor of Physics Petriina Paturi highlights a report by the International Energy Agency (IEA) showing that in some countries, such as Ireland, more than 20 percent of the country's electricity is used by large data centres.
Globally, the figure is more modest, at around 2 percent of total electricity, but it is expected to double in a few years.
According to Paturi, one reason for the rapid growth in consumption is artificial intelligence.
“Each question posed to AI takes ten times more energy than a regular Google search,” says Paturi, whose research group is developing new types of energy-efficient memory resistors.
AI is not the sole cause of data centre power consumption, but the number of AI users is growing rapidly and evolving applications are demanding increasing amounts of computing power.
“This means that the growth in consumption will only accelerate unless we find ways to curb it. One option is to build large data centres in colder countries. Another option is to develop more efficient electronics.
Paturi compares energy consumption to the human brain. For example, in a neuromorphic computer, a single synaptic learning event consumes a nanojoule with conventional electronics. If the memristors developed by the research group were used, energy consumption would be a thousand times lower. And in the human brain, consumption is a thousand times less than this.
“The processing power of the brain is incredible when compared to a semiconductor computer of comparable size. The difference between them is significant. By using memristors, we could get closer to the energy efficiency of the brain," says Paturi.
Invention developed in Turku is a world leader
A memristor is a new type of super-efficient nanoscale memory resistor that can be used in a variety of applications that mimic brain activity. They are being developed around the world by research groups at universities and technology giants.
The University of Turku has invented its own patented material and structure for memristors, giving the finished component top-class properties.
The invention was sparked a decade ago when Paturi, who had previously studied low-bandwidth manganites, and her research group realised that semiconducting manganite materials could be a perfect fit for memristors. However, they needed to be processed first.
The researchers developed a completely new type of material, a gadolinium-calcium-manganese oxide compound. It had excellent conductivity for a memristor and its scalability was also exceptional, meaning that it would enable the fabrication of really small memristors.
A project is already underway to commercialise the memristors, with the aim of taking the component to international markets. But at the moment, this technology is still only produced for research and development purposes.
“For example, memristors are being tested in a friction-sensing robot currently developed by Associate Professor Wallace Bessa at the Faculty of Technology. The robot could be used in autonomous cars or drones, for example. Developing better autonomous driving requires very fast and energy-efficient computing devices capable of learning, with computation performed on-device rather than in the cloud.
According to Paturi, memristors are at their most natural in such computing devices. Another suitable target could be various battery-powered sensors where low power consumption is important.
Theoretically, they could be used in any electronics, but the features of a memristor do not always provide additional benefit compared to conventional electronics. They are most useful in neural networks or neuromorphic computing devices, which are also needed for artificial intelligence.
“If all neural networks used memristors, their power consumption could be reduced to as little as one-thousandth of the current level. The number of neural networks in the world has multiplied at a tremendous rate, so there could be a huge demand for memristors if they could be made commercially available. We are currently working on a solution,” promises Paturi.
"I would say our memristor is the best."
– Petriina Paturi
The main difference between the memristor developed in Turku and its competitors is precisely its unique material that enables the production of smaller memory resistors than in competing devices. In addition, the material is so conductive that the resistor can be highly efficient with a very light and simple structure.
“Our memristor uses only a small amount of raw materials, making it more environmentally friendly to manufacture. At the same time, the price of the product can be kept as low as possible for the end user. “
It sounds like the memristor developed in Turku would be better than its competitors in almost all features.
“I would say ours is the best," laughs Paturi.
The idea of the research group has already been recognised by others. Last autumn, it won two Finnish innovation prizes. The Union of Professional Engineers in Finland awarded it the Engineering Invention of the Year, and the Junior Chamber International in Finland named it the winner of the innovation series of the Productive Idea competition. The memristor from Turku even got featured on the famous Times Square billboards in New York.
“This truly is inspiring! It is great to be involved in such interesting and exciting research," says Paturi.
At the same time, she points out that inventions are not made from scratch. The development of memristors has also required expensive equipment and the construction of clean rooms. She would like to give special thanks to the Jenny and Antti Wihuri Foundation.
“Without all the support we have received, our work would not have been possible and this invention would not have been created," says Paturi.
Text: Liisa Reunanen
Translation: Saara Yli-Kauhaluoma
Photos: Hanna Oksanen
