Wearable light emitting transistors for future communication devices

Lead Research Organisation: University of Exeter
Department Name: Engineering Computer Science and Maths

Abstract

Nowadays, display and communication devices are supplementary items, many times posing transportation problems to the user, due to volume, weight and size, making them uncomfortable and inconvenient to use and carry. Current technology and innovation efforts look for alternative substrates, materials and ideas that eliminate or reduce much of these inconveniences. Products have been developed not only with reduced size and weight, but also improved flexibility. These products, including e-readers or rollable displays mimic more traditional forms of displaying information such as the information printed on paper. However, all of these applications are far from being fully integrated in basic objects of our society.

This proposal seeks to establish a new ground-breaking technology for flexible, transparent, comfortable and easy to carry textile-embedded communication devices. The approach to realize this aim is to build the first fibre-embedded device with controllable light emission: a light-emitting transistor completely entrenched in a fabric. This will be achieved by combining organic semiconductors and dielectrics with graphene as conductive layer, in a novel concept that merges flexibility, transparency, optoelectronic properties and fabrication compatibility of these materials with textiles.

Graphene and organic semiconductors combine mechanical flexibility and optical transparency with excellent electronic characteristics and low-temperature processing and are ideal for non-conventional substrates such as fibres of textiles. With just 3-4 Å thickness, monolayer graphene not only ensures high transparency, but it is bendable and stretchable. Together with its robustness and high conductivity, it is an extremely good candidate to replace current metallic electrodes. Polymers and organic small molecules, on the other hand, present a wide range of electrical behaviour, from conductors to insulators, with the possibility of solution processing. Several families of organic compounds present semiconductor behaviour and are successfully used in organic field-effect-transistors. Another advantage of organic materials is the possibility of chemical modification to add functionalities or change mechanical and optoelectronic properties. Such unique properties, allied with the potential that organic-semiconductor devices have demonstrated for display technology make it reasonable that a ground-break idea of wearable displays is achievable.

The outputs of the proposed project, the development of textile-embedded optoelectronic devices, will be fundamental to the development of smart textiles as well as of transparent and flexible electronics. Achieving this goal is of strategic importance to secure a leading role of UK in these research fields. The results of this research are also likely to be of wide use in consumer applications. For instance, the project will allow the development of completely new approaches for integrated electronics and forms of displaying information, capable to be embedded into our everyday clothing. Since textiles are so present in society, the ability to embed display-based information and communication devices into wearable textiles would transform our clothing into mobile phones, displays with electronic newspapers or GPS-activated maps, and would certainly facilitate interactions and exchanges between individuals and communities. Such devices represent a radical alternative to conventional technologies as they must bend, stretch, compress, twist and deform into complex shapes while maintaining their levels of performance and reliability. Establishing the foundations for this future in electronics is also essential for other societal needs, such as biomedical monitoring, communication tools for the sensory impaired people, and personal security.

Planned Impact

Devices embedded into textiles, for simple, comfortable and handy transport could be used for display and communication devices, expanding social interactions. For instance, simple information display on clothes that could change colour for security alert, or display with informative tags in sport or social events could be attained. Furthermore, simple information like an address, maps or medicine alert to provide assistance to children or senior people could also be envisioned. The use of embedded discrete wearable devices would avoid loses and facilitate acceptance from the person who would wear it. More complex displays, combining communication technology could lead in the future to textile GPS or phones. Moreover, through the development of new fabrication techniques and innovative materials, this strategy could also be applied to other type of textile applications in the fields of health, security and energy harvesting. For example, in health care monitoring, fibre embedded light emitting devices can be used to integrate monitor displays that show and govern the usage of drug implants through a wireless communication system. Since textiles are a basic product in people's life, completely integrated devices could improve social care and inclusion, as well as opening new possibilities for health care. Wearable power sources that could use body heat and kinetic energy produced on movement as well as textile photovoltaics are also potential applications where technology developed by this project could be employed.

The outputs of our project, the development of graphene and organic materials based optoelectronic devices, will be fundamental to the development of transparent and flexible electronics. We have identified a number of areas that would potentially benefit from graphene and organic materials based transparent flexible devices. These include: photovoltaic devices, electronic circuits, sensors, detectors and displays. The ability to embed transparent graphene-based electronic circuits, sensors and detectors into windows in public areas is of great interest and would improve national security. Transparent devices have the potential to improve social welfare by transforming the windscreens of cars, trains and airplanes into display controls and GPS-activated maps. Transparent photovoltaic devices embedded in the windows in houses and offices will allow the production of electricity via solar energy. Graphene could be orders of magnitude cheaper than the indium tin oxide (ITO) electrodes and the silicon transistors currently used in vast numbers in many industrial sectors. The use of graphene in these devices opens up an entirely new avenue towards the development of efficient and economical transparent optoelectronics, thus fostering the economic competitiveness of the UK. Apart from their expense, today`s transparent devices, based on ITO, can create major recycling problems. Many other materials that are currently used in these devices, such as carbon nanotubes may be carcinogenic if they become airborne and are inhaled. The chances that graphene could be inhaled are very low since this material is a two-dimensional sheet which can be fabricated in large areas (100cmx100cm). Thus, by incorporating graphene in devices, the components of the future will not have negative effects on our health, will be much easier to recycle, and thereby will be environmentally more attractive.

Publications

10 25 50
 
Description Ground-breaking research has successfully created the world's first truly electronic textile, using the wonder material Graphene.

An international team of scientists, including Professor Monica Craciun from the University of Exeter, have pioneered a new technique to embed transparent, flexible graphene electrodes into fibres commonly associated with the textile industry.

The discovery could revolutionise the creation of wearable electronic devices, such as clothing containing computers, phones and MP3 players, which are lightweight, durable and easily transportable.
Exploitation Route This new research has identified that 'monolayer graphene', which has exceptional electrical, mechanical and optical properties, make it a highly attractive proposition as a transparent electrode for applications in wearable electronics.
The concept of wearable technology is emerging, but so far having fully textile-embedded transparent and flexible technology is currently non-existing. Therefore, the development of processes and engineering for the integration of graphene in textiles would give rise to a new universe of commercial applications. We are surrounded by fabrics, the carpet floors in our homes or offices, the seats in our cars, and obviously all our garments and clothing accessories. The incorporation of electronic devices on fabrics would certainly be a game-changer in modern technology.

"All electronic devices need wiring, so the first issue to be address in this strategy is the development of conducting textile fibres while keeping the same aspect, comfort and lightness. The methodology that we have developed to prepare transparent and conductive textile fibres by coating them with graphene will now open way to the integration of electronic devices on these textile fibres
Sectors Digital/Communication/Information Technologies (including Software),Electronics,Energy,Healthcare,Leisure Activities, including Sports, Recreation and Tourism

URL http://www.exeter.ac.uk/news/featurednews/title_450654_en.html
 
Description Dr Ana Neves participates in the Soapbox Science event in Exeter. During her spell on the soapbox, Dr Ana Neves amazed the audience with the possibilities of smart textiles and her research into building electronic devices directly onto textile fibres, posing the question, "What if you could make a phone call using your sweater instead of your mobile?" Female scientists took to their soapboxes at city centre spectacle. A host of Devon's leading female scientists took to their soapboxes at the weekend to showcase their fascinating science to the general public at a free event in Exeter city centre. On Saturday 13th June 2015 Princesshay Square was transformed into a hub of scientific learning and discussion, with 12 experts speaking on subjects as far ranging as the human brain, alien planets, animal migration and wearable electronics. This event was part of a nation-wide initiative by Soapbox Science, which aims to bring science to the people and challenge gender stereotypes in science careers by raising the profile of women in science. Its organisers want to make sure that everyone has the opportunity to enjoy, learn from, heckle, question, probe, interact with and be inspired by some of our leading scientists.
First Year Of Impact 2015
Sector Digital/Communication/Information Technologies (including Software),Education
Impact Types Cultural,Societal

 
Description Graphene photonic metamaterials for fast information and communication photonics. Royal Society (International Exchange Scheme with Russia).
Amount £12,000 (GBP)
Organisation The Royal Society 
Sector Charity/Non Profit
Country United Kingdom
Start 07/2016 
End 06/2018
 
Description Imperceptible, flexible and ultra-lightweight radioactivity detectors, Defence Science and Technology Laboratory (DSTL) UK-France grant scheme on New materials and Nanotechnologies
Amount £148,000 (GBP)
Organisation Defence Science & Technology Laboratory (DSTL) 
Sector Public
Country United Kingdom
Start 09/2015 
End 09/2019
 
Description Long distance spin communication in high quality single domains graphene. Royal Society (International Exchange Scheme with Sweden,
Amount £12,000 (GBP)
Organisation The Royal Society 
Sector Charity/Non Profit
Country United Kingdom
Start 07/2016 
End 06/2018
 
Description Marie Curie Individual Fellowship
Amount € 195,450 (EUR)
Funding ID EU proposal 701704 - FLAIR 
Organisation Marie Sklodowska-Curie Actions 
Sector Charity/Non Profit
Country Global
Start 03/2016 
End 10/2019
 
Description Marie Curie individual fellowship
Amount € 195,450 (EUR)
Funding ID project 704963 - E-TEX 
Organisation Marie Sklodowska-Curie Actions 
Sector Charity/Non Profit
Country Global
Start 09/2016 
End 09/2016
 
Description Room Temperature Quantum Electronics, Leverhulme research grants
Amount £256,000 (GBP)
Organisation The Leverhulme Trust 
Sector Charity/Non Profit
Country United Kingdom
Start 03/2017 
End 03/2020
 
Description Room temperature quantum electronics. Royal Society (International Exchange Scheme with the Netherlands
Amount £12,000 (GBP)
Organisation The Royal Society 
Sector Charity/Non Profit
Country United Kingdom
Start 07/2016 
End 06/2018
 
Description Royal Academy of Engineering Research Fellowship for Dr Freddie Withers
Amount £320,000 (GBP)
Organisation Royal Academy of Engineering 
Sector Charity/Non Profit
Country United Kingdom
Start 10/2016 
End 01/2019
 
Description Participation to nation-wide Soapbox Science. 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact This initiative aims to bring science to the people and challenge gender stereotypes in science careers by raising the profile of women in science. My research group has participated to this event on the 13th June 2015 in Princesshay Square in Exeter, with one of my female associate research fellows (Dr Ana Neves) presenting our work on graphene-based wearable electronics. See university press release: Female scientists took to their soapboxes at city centre spectacle "During her spell on the soapbox, Dr Ana Neves of Engineering amazed the audience with the possibilities of smart textiles and her research into building electronic devices directly onto textile fibres, posing the question, "What if you could make a phone call using your sweater instead of your mobile?"
Year(s) Of Engagement Activity 2015
URL http://www.exeter.ac.uk/news/university/title_456565_en.html
 
Description press release 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Graphene holds key to unlocking creation of wearable electronic devices
"Ground-breaking research has successfully created the world's first truly electronic textile, using the wonder material Graphene"
Year(s) Of Engagement Activity 2015
URL http://www.exeter.ac.uk/news/featurednews/title_450654_en.html