G-Sense
Lead Research Organisation:
University of Surrey
Department Name: Physics
Abstract
The project consortium: M-Solv (a process developer), Thomas Swan (a graphene manufacturer), Printed Electronics Ltd
(an inkjet ink formulator) and the University of Surrey, aims to bring innovations to capacitive touch sensor (CTS)
manufacture. In a typical consumer device, CTS comprises of structured transparent conductors (TC), which sense the
capacitance variations when fingers approach. Conventional CTS are made of indium tin oxide (ITO). However, indium is
known to be scarce and hence expensive in the near future. This project will explore the use of silver nanowire (AgNW),
together with graphene to replace ITO for fabricating CTS at a much lower cost. We have developed optimised silver
AgNW films and made functional CTS based on such coatings. We also have recently filed a patent for depositing
graphene platelets (GP) onto networks of very low density AgNW to change its sheet resistance by orders of magnitude
from Mohm/sq to less than hundreds ohm/sq. The project takes the idea further and aims to revolutionise the technical
approach of CTS manufacture by printing GP onto AgNW networks to directly form electrodes for CTS, while the industry is
currently manufacturing CTS by depositing large area of transparent conduct and subsequent patterning to structure
electrodes. Two printing techniques, inkjet printing and relief printing, are chosen to demonstrate the idea of the project; the
low cost AgNW/graphene structured film, the material-on-demand approach, and the rapid selective deposition techniques
can provide massive cost advantage (~10x) to CTS manufacture.
(an inkjet ink formulator) and the University of Surrey, aims to bring innovations to capacitive touch sensor (CTS)
manufacture. In a typical consumer device, CTS comprises of structured transparent conductors (TC), which sense the
capacitance variations when fingers approach. Conventional CTS are made of indium tin oxide (ITO). However, indium is
known to be scarce and hence expensive in the near future. This project will explore the use of silver nanowire (AgNW),
together with graphene to replace ITO for fabricating CTS at a much lower cost. We have developed optimised silver
AgNW films and made functional CTS based on such coatings. We also have recently filed a patent for depositing
graphene platelets (GP) onto networks of very low density AgNW to change its sheet resistance by orders of magnitude
from Mohm/sq to less than hundreds ohm/sq. The project takes the idea further and aims to revolutionise the technical
approach of CTS manufacture by printing GP onto AgNW networks to directly form electrodes for CTS, while the industry is
currently manufacturing CTS by depositing large area of transparent conduct and subsequent patterning to structure
electrodes. Two printing techniques, inkjet printing and relief printing, are chosen to demonstrate the idea of the project; the
low cost AgNW/graphene structured film, the material-on-demand approach, and the rapid selective deposition techniques
can provide massive cost advantage (~10x) to CTS manufacture.
Planned Impact
Project success has clear financial impact and can potentially place the UK at the forefront of a multi-billion dollar industry
and more importantly a market where the potential of graphene can be truly realized. In recent years the market for
Capacitive Touchscreen Sensors (CTS) has grown to 2 billion units or $40 billion per annum driven by the smartphone and
tablet markets. However the commercial impact maybe more general as the growth is forecast to continue with 15% CAGR as touch technology is adopted in ultra books, laptops and more widely: e.g. automotive controls, white goods, medical,
industrial, etc. The introduction of our novel CTS will mean M-Solv, as the end user in the consortium will have a
sustainable, differentiated and low cost product with strong IP giving a significantly competitive advantage.
A successful project will also result in financial success for the other industrial partners. Thomas Swan can sell graphene
products in kg scale quantities (£100K) while Printed electronics Ltd can make profits from £150K worth of graphene based
ink, based on materials used for every million phone-size CTS sold. For both of these partners, the project is a good
starting point to open up new market opportunities and increase their market share of the graphene and conductive ink
industries, which will generate a forecasted $2 billion and $100 million respectively in revenue by 2019 [IDTechEx].
Outside the consortium, there are benefits to the machine supply chain (£1M). There is also potential to support AgNW and
graphene based businesses in the UK by supplying equipment and materials.
The project will generate funding for future R&D and research student training at the University of Surrey, by licensing the
IP developed for AgNW/G based electrodes. There will be opportunities for UK-China and China-UK, travel & working
abroad with the potential collaborations between the consortium and M-Solv's Hong Kong-based parent company CNI.
The replacement of ITO by our proposed technology may have significant health implications. Indium is a toxic material and
its continued mining to meet the industries needs has detrimental effects on the health and safety of miners.
and more importantly a market where the potential of graphene can be truly realized. In recent years the market for
Capacitive Touchscreen Sensors (CTS) has grown to 2 billion units or $40 billion per annum driven by the smartphone and
tablet markets. However the commercial impact maybe more general as the growth is forecast to continue with 15% CAGR as touch technology is adopted in ultra books, laptops and more widely: e.g. automotive controls, white goods, medical,
industrial, etc. The introduction of our novel CTS will mean M-Solv, as the end user in the consortium will have a
sustainable, differentiated and low cost product with strong IP giving a significantly competitive advantage.
A successful project will also result in financial success for the other industrial partners. Thomas Swan can sell graphene
products in kg scale quantities (£100K) while Printed electronics Ltd can make profits from £150K worth of graphene based
ink, based on materials used for every million phone-size CTS sold. For both of these partners, the project is a good
starting point to open up new market opportunities and increase their market share of the graphene and conductive ink
industries, which will generate a forecasted $2 billion and $100 million respectively in revenue by 2019 [IDTechEx].
Outside the consortium, there are benefits to the machine supply chain (£1M). There is also potential to support AgNW and
graphene based businesses in the UK by supplying equipment and materials.
The project will generate funding for future R&D and research student training at the University of Surrey, by licensing the
IP developed for AgNW/G based electrodes. There will be opportunities for UK-China and China-UK, travel & working
abroad with the potential collaborations between the consortium and M-Solv's Hong Kong-based parent company CNI.
The replacement of ITO by our proposed technology may have significant health implications. Indium is a toxic material and
its continued mining to meet the industries needs has detrimental effects on the health and safety of miners.
Organisations
Publications
Garriga R
(2016)
Two-Dimensional, pH-Responsive Oligoglycine-Based Nanocarriers.
in ACS applied materials & interfaces
Large M
(2016)
Predicting the optoelectronic properties of nanowire films based on control of length polydispersity
in Scientific Reports
Large MJ
(2016)
Finite-size scaling in silver nanowire films: design considerations for practical devices.
in Nanoscale
Large MJ
(2018)
Functional liquid structures by emulsification of graphene and other two-dimensional nanomaterials.
in Nanoscale
Large MJ
(2017)
Selective Mechanical Transfer Deposition of Langmuir Graphene Films for High-Performance Silver Nanowire Hybrid Electrodes.
in Langmuir : the ACS journal of surfaces and colloids
Martine P
(2015)
Carbon Nanotube Networks Reinforced by Silver Nanowires with Improved Optical Transparency and Conductivity
in APS Meeting Abstracts
Worajittiphon P
(2015)
Stretchable Conductive Networks of Carbon Nanotubes Using Plasticized Colloidal Templates
in Frontiers in Materials
| Description | In this work, we found that silver nanowire hybrid electrodes prepared through the addition of small quantities of pristine graphene by mechanical transfer deposition from surface- assembled Langmuir films produce high performance transparent electrodes. This technique is a fast, efficient, and facile method for modifying the optoelectronic performance of AgNW films. We demonstrated that it is possible to use this technique to perform a two-step device production by selective patterning of the stamp used, leading to controlled variation in the local sheet resistance across a device. This is particularly attractive for producing extremely low cost sensors on arbitrarily large scales. Our findings address some of the concerns surrounding the use of AgNW films as replacements for indium tin oxide (ITO), namely, the use of scarce materials and poor stability of AgNWs against flexural and environmental degradation. |
| Exploitation Route | We have demonstrated a method for the production of AgNW:G hybrid films based on the mechanical transfer deposition of graphene onto spray-deposited AgNW films. These hybrid films show an orders-of-magnitude decrease in sheet resistance relative to that of the pristine nanowire films. As well as having superior electro-optical properties, AgNW:G hybrids prepared by direct L-S deposition have been shown to have additional benefits such as stabilization against atmospheric degradation and mechanical annealing. We believe that these properties will also be characteristic of stamped AgNW:G films, albeit dependent on the transferred graphene coverage. Mechanical transfer deposition facilitates one-step electrode deposition, achieving levels of track-to-gap sheet resistance contrast required for device production with spatially resolved features. Such local modification of the film properties cannot be achieved directly using L-S deposition. By optimizing the deposited graphene film density, we have demonstrated resistance contrast values of approximately 103 with a negligible change in the film transmittance. Together, these characteristics of stamped AgNW:G hybrids make them an attractive option for low-cost, scalable transparent device electrodes. Our work could be taken forward by a commercial transparent electrode or touch screen manufacturer such as our partner M-SOLV. |
| Sectors | Aerospace, Defence and Marine,Chemicals,Digital/Communication/Information Technologies (including Software),Electronics,Leisure Activities, including Sports, Recreation and Tourism,Manufacturing, including Industrial Biotechology |
| Description | The findings of the project so far has provided proof of concept verification to our industrial partners (funded through Innovate) that the graphene/nanowire hybrid system can potentially be used as a viable alternative to ITO for touch screen applications. The research has offered Thomas-Swan ( a graphene producer) vital data to modify and tailor their approach to processing their elicarb material for such applications. The project has so far shown that ,unlike their main key market areas, materials processed for the applications outlined in this project must have specifically tailored aspect ratios and surface chemistries. The project has allowed the device manufacturer, M-SOLV, to calculate a realistic costing for the material to be used as the active layer in touch sensor devices as they think about scale up. |
| First Year Of Impact | 2015 |
| Sector | Chemicals,Digital/Communication/Information Technologies (including Software),Electronics,Manufacturing, including Industrial Biotechology |
| Impact Types | Economic |