News Release

Making the Internet of Things possible with a new breed of 'memristors'

Easily printable, organic thin films can retain data for more than 10 years without power, work with low voltages -- and become the building block of future computers that mimic the human brain

Peer-Reviewed Publication

Aalto University

The Probe-station Device


Credit: Tapio Reinekoski

The internet of things is coming, that much we know. But still it won't; not until we have components and chips that can handle the explosion of data that comes with IoT. In 2020, there will already be 50 billion industrial internet sensors in place all around us. A single autonomous device - a smart watch, a cleaning robot, or a driverless car - can produce gigabytes of data each day, whereas an airbus may have over 10 000 sensors in one wing alone.

Two hurdles need to be overcome. First, current transistors in computer chips must be miniaturized to the size of only few nanometres; the problem is they won't work anymore then. Second, analysing and storing unprecedented amounts of data will require equally huge amounts of energy. Sayani Majumdar, Academy Fellow at Aalto University, along with her colleagues, is designing technology to tackle both issues.

Majumdar has with her colleagues designed and fabricated the basic building blocks of future components in what are called "neuromorphic" computers inspired by the human brain. It's a field of research on which the largest ICT companies in the world and also the EU are investing heavily. Still, no one has yet come up with a nano-scale hardware architecture that could be scaled to industrial manufacture and use.


Basic components for computers that work like the brain

In their recent article in Advanced Functional Materials, Majumdar and her team show how they have fabricated a new breed of "ferroelectric tunnel junctions", that is, few-nanometre-thick ferroelectric thin films sandwiched between two electrodes. They have abilities beyond existing technologies and bode well for energy-efficient and stable neuromorphic computing.

The junctions work in low voltages of less than five volts and with a variety of electrode materials - including silicon used in chips in most of our electronics. They also can retain data for more than 10 years without power and be manufactured in normal conditions.

Tunnel junctions have up to this point mostly been made of metal oxides and require 700 degree Celsius temperatures and high vacuums to manufacture. Ferroelectric materials also contain lead which makes them - and all our computers - a serious environmental hazard.


What makes ferroelectric thin film components great for neuromorphic computers is their ability to switch between not only binary states - 0 and 1 - but a large number of intermediate states as well. This allows them to 'memorise' information not unlike the brain: to store it for a long time with minute amounts of energy and to retain the information they have once received - even after being switched off and on again.




Sayani Majumdar, Binbin. Chen, Qi Hang Qin, Himadri. S. Majumdar, Sebastiaan van Dijken, Advanced Functional Materials 2017, 1703273.
'Electrode Dependence of Tunneling Electroresistance and Switching Stability in Organic Ferroelectric P(VDF-TrFE)-Based Tunnel Junctions'

Contact information:

Sayani Majumdar, Academy Fellow, Aalto University
phone: 358-50-363-3627
