[ Back to EurekAlert! ]


[ | E-mail ] Share Share

Contact: Michael Bishop
Institute of Physics

Brain process takes paper shape

A paper-based device that mimics the electrochemical signalling in the human brain has been created by a group of researchers from China.

The thin-film transistor (TFT) has been designed to replicate the junction between two neurons, known as a biological synapse, and could become a key component in the development of artificial neural networks, which could be utilised in a range of fields from robotics to computer processing.

The TFT, which has been presented today, 13 February, in IOP Publishing's journal Nanotechnology, is the latest device to be fabricated on paper, making the electronics more flexible, cheaper to produce and environmentally friendly.

The artificial synaptic TFT consisted of indium zinc oxide (IZO), as both a channel and a gate electrode, separated by a 550-nanometre-thick film of nanogranular silicon dioxide electrolyte, which was fabricated using a process known as chemical vapour deposition.

The design was specific to that of a biological synapse—a small gap that exists between adjoining neurons over which chemical and electrical signals are passed. It is through these synapses that neurons are able to pass signals and messages around the brain.

All neurons are electrically excitable, and can generate a 'spike' when the neuron's voltage changes by large enough amounts. These spikes cause signals to flow through the neurons which cause the first neuron to release chemicals, known as neurotransmitters, across the synapse, which are then received by the second neuron, passing the signal on.

Similar to these output spikes, the researchers applied a small voltage to the first electrode in their device which caused protons—acting as a neurotransmitter—from the silicon dioxide films to migrate towards the IZO channel opposite it.

As protons are positively charged, this caused negatively charged electrons to be attracted towards them in the IZO channel which subsequently allowed a current to flow through the channel, mimicking the passing on of a signal in a normal neuron.

As more and more neurotransmitters are passed across a synapse between two neurons in the brain, the connection between the two neurons becomes stronger and this forms the basis of how we learn and memorise things.

This phenomenon, known as synaptic plasticity, was demonstrated by the researchers in their own device. They found that when two short voltages were applied to the device in a short space of time, the second voltage was able to trigger a larger current in the IZO channel compared to the first applied voltage, as if it had 'remembered' the response from the first voltage.

Corresponding author of the study, Qing Wan, from the School of Electronic Science and Engineering, Nanjing University, said: 'A paper-based synapse could be used to build lightweight and biologically friendly artificial neural networks, and, at the same time, with the advantages of flexibility and biocompatibility, could be used to create the perfect organism–machine interface for many biological applications.'


From Thursday 12 February, this paper can be downloaded from http://iopscience.iop.org/0957-4484/25/9/094001/article

Notes to Editors


1. For further information, a full draft of the journal paper or contact with one of the researchers, contact IOP Press Officer, Michael Bishop:

Tel: 0117 930 1032
E-mail: michael.bishop@iop.org

For more information on how to use the embargoed material above, please refer to our embargo policy.

IOP Publishing Journalist Area

2. The IOP Publishing Journalist Area gives journalists access to embargoed press releases, advanced copies of papers, supplementary images and videos. In addition to this, a weekly news digest is uploaded into the Journalist Area every Friday, highlighting a selection of newsworthy papers set to be published in the following week.

Login details also give free access to IOPscience, IOP Publishing's journal platform.

To apply for a free subscription to this service, please email Michael Bishop, IOP Press Officer, michael.bishop@iop.org, with your name, organisation, address and a preferred username.

Low-voltage protonic/electronic hybrid indium zinc oxide synaptic transistors on paper substrates

3. The published version of the paper 'Low-voltage protonic/electronic hybrid indium zinc oxide synaptic transistors on paper substrates' (Guodong Wu et al 2014 Nanotechnology 25 094001) will be freely available online from 13 February 2014. It will be available at http://iopscience.iop.org/0957-4484/25/9/094001/article


4. Nanotechnology encompasses the understanding of the fundamental physics, chemistry, biology and technology of nanometre-scale objects.

IOP Publishing

5. IOP Publishing provides a range of journals, conference proceedings, magazines, websites, books and other services that enable researchers and research organisations to achieve the biggest impact for their work.

We combine the culture of a global learned society with highly efficient and effective publishing systems and processes. We serve researchers in the physical and related sciences in all parts of the world through our offices in the UK, US, Germany, China and Japan, and staff in many other locations including Mexico and Russia.

IOP Publishing is a wholly owned subsidiary of the Institute of Physics. The Institute is a leading international scientific society with over 55 thousand members promoting physics and bringing physicists together for the benefit of all.

Surplus generated by IOP Publishing is gift aided to the Institute to support science and scientists in both the developed and developing world.

Access to Research

6. Access to Research is an initiative through which the UK public can gain free, walk-in access to a wide range of academic articles and research at their local library. This article is freely available through this initiative. For more information, go to http://www.accesstoresearch.org.uk

The Institute of Physics

7. The Institute of Physics is a leading scientific society. We are a charitable organisation with a worldwide membership of more than 50,000, working together to advance physics education, research and application. We engage with policymakers and the general public to develop awareness and understanding of the value of physics and, through IOP Publishing, we are world leaders in professional scientific communications. Go to http://www.iop.org

[ Back to EurekAlert! ] [ | E-mail Share Share ]


AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.