For the internet of things to penetrate our everyday lives as seamlessly as technologies such as Wi-Fi do, there are still two major hurdles that need to be overcome.
First, a way needs to be discovered to miniaturize transistors in computer chips and brought down in the scale of nanometers. While this can be done in theory, the current transistors don’t work anymore when it is actually done. Second, the analysis and storage of the unprecedented amounts of data produced by smart connected devices require equally high volumes of energy. Sayani Majumdar from the Aalto University is designing the necessary technologies to solve both these issues.
The team has developed a new variety of ferroelectric tunnel junctions. These nanometer-range ferroelectric thin films fitted between two electrodes are said to possess efficient neuromorphic computing and energy efficiency capabilities much better than existing technologies. The researchers say that these junctions work in voltages as low as five volts or even lesser and are compatible with a number of electrode materials, including silicon, which is used in most electronics devices presently. These junctions can also preserve data, without power, for over 10 years and can be manufactured in natural circumstances.
Till now, tunnel junctions have been made of metal oxides and require special conditions with high temperature and vacuum for manufacturing. Moreover, lead is present in most ferroelectric materials, which can pose a serious hazard to the environment. The newly devised ferroelectric thin film components are better for neuromorphic computers as they can switch not only between binary states like most electronic components presently do, but also a large number of intermediate states. This makes them ‘memristors’ – transistors that can memorise information.