Memorandum 134
Submission from the Institute of Physics
(IoP)
The current and future roles of engineers in the
field of plastic electronics
1.1 The field of plastic electronics has
its roots in physics and chemistry research into the fundamental
properties of polymers, but in the development of future applications
and devices, engineers and engineering are essential. Currently
engineers are predominantly engaged in translating scientific
innovations and R&D into potential device technology. Further
development of plastic electronics technologies and applications
will require engineers working in a range of fields:
Electrical and Electronic Engineering: Plastic
electronic devices behave in a different manner to traditional
electronic circuits based on silicon; as such they require the
design and implementation of new structures. For example, organic
light emitting diode (OLED) based displays require different driving
electronics than those used in conventional liquid crystal displays
(LCDs). Organic photovoltaic (OPV) solar cells will require new
power electronics to link them into the national grid.
Optical Engineering: The coupling of light out
of OLED based displays, and coupling light into OPVs, requires
new optical designs and modeling to maximise efficiency.
Chemical Engineering: Solution "processable"
plastic electronics require detailed control and understanding
of many factors (eg viscosity, evaporation rate) in the polymer
semiconductor formulations. All of these factors need to be adjusted
depending on the production method used for fabrication. Furthermore
there is the need to scale-up the production of plastic electronic
materials from milligrams in the laboratory to kilograms in factories,
bringing together reactor and reaction engineering with process
modeling and control. This requires chemical engineering design
of the large scale production facilities needed to mass produce
conjugated polymers, small molecules and fullerene based materials.
Production Engineering: Production of solution
processed plastic electronics requires a novel range of fabrication
facilities. The most fully developed is of these in the UK is
ink-jet printing, but other potential techniques include: gravure
printing, "flexo printing", screen printing, micro-stamping
and hot-stamping. Challenges in this area are both registration
between different printed layers, as well as resolution (minimum
feature size) to maximize device performance.
Environmental Engineering: Plastic electronics
is a developing technology and it should be possible to minimize
the environmental impact of production from the bottom up, both
in use and disposal. This includes energy efficiency, biological
toxicity and the use of biodegradable and compostable materials.
The latter aspect covers not only the electronic materials themselves,
but also their production solvents (eg use of water and alcohols
as opposed to chlorinated solvents) and device encapsulation materials.
The potential for plastic electronics in the UK/global
economy
2.1 The economic impact of the plastic electronics
sector could be very significant, both in terms of businesses
and jobs created and in terms of revenue. The global market is
currently worth around $1bn with predictions that this will rise
dramatically over the next two decades reaching $30 bn by 2015[20]
and $330 billion by 2027[21].
Conventional fabrication plants for electronics and displays require
substantial capital resources (of the order of $100 millions).
Plastic electronic devices in contrast can be produced through
ink-jet printing at room temperature and pressure. As such fabrication
plant cost is greatly reduced moving within the reach of small
and medium-sized companies.
2.2 Plastic electronics have the potential
to address some of the key challenges of this century: environmental
protection, and energy generation and usage, through the low energy
consumption in production, use and recycling, as compared with
traditional electronic technologies. There is also the potential
for devices to be engineered to have a much lower biological impact
in terms of toxic waste in production and disposal.
2.3 Some key potential usages of plastic
electronics are:
Solar cells: OPV solar cells are lightweight,
flexible, can cover large areas and can be mass-produced through
solution processing. Although current efficiencies are relatively
low (5%) compared to their inorganic semiconductor counterparts
(28%), their comparatively low production costs compensate for
this in the short term, and in the longer term there is scope
for improvement. Such technology could have a major impact on
the field of renewable energy generation.
Displays & lighting: OLED-based information
displays (both single-colour and full-colour) and large-area lighting
are lightweight, flexible and can be mass-produced by solution
processing. OLED-based devices have the same richness of colour
of a conventional cathode ray tube (CRT) or plasma screens but
have advantages in energy efficiency, size and weight. Large-area
OLED lighting is also energy efficient and can be designed in
any type of curved shape or flexible structure, producing a range
of exciting new design and products.
Display electronics, radio frequency identity
tags (RFID), data storage & processing: Organic field-effect
transistors (OFETs) have similar advantages to OPVs and OLEDs.
They can be used as thin film transistors in liquid crystal displays
(LCD) and electronic paper displays, allowing the production of
flexible, lightweight devices. They can also be used to produce
cheap, printed RFID tags for commercial and security measures.
Novel lightweight electronic devices are also possible, with the
potential for moving into new three-dimensional architectures
not possible with conventional silicon based electronics.
Sensors: Organic photodiodes (OPDs) can be used
to produce new imaging and sensing devices. These include biological
sensors (eg the replacement human eye project at Imperial College)
and X-ray imaging devices for medical use.
Telecom & optical signal processing: Polymer
and small molecule semiconductors can be used in optical amplifiers
and optically pumped lasers for use in fibre optic networks. Their
ease of processing could be used to fabricate using simple methods
a range of different optical device architectures for telecommunications,
local area networks and all-optical processing.
2.4 There are also hybrid technologies that
could combine conventional silicon electronics and organic electronics
on both glass and plastic substrates. These could provide a quicker
route to market than novel technologies.
2.5 Current production techniques are principally
molecular deposition by thermal evaporation and ink-jet printing
from solution. Strong opportunities exist in developing these
and other production methods. Highly specialized, precision engineering
firms will be needed to develop these new techniques; however,
there is a very weak UK presence within these fields compared
with other European nations (eg Switzerland, Germany and Finland).
How universities, industry, venture capital and
Government are involved in the development of the UK plastic electronics
sector
Universities
3.1 There are several examples of a very
high level of involvement in the basic research that underpins
plastic electronics within the UK. Universities currently undertaking
this research area include: Imperial College, Cambridge, Oxford,
UCL, QMUL, Sheffield, Manchester, St Andrews and Durham, principally
in the departments of physics, chemistry and materials science.
The main research interests are in displays and solar cells, but
there are other possible applications in sensors.
Industry
3.2 There is a broad range of companies
currently involved in plastic electronics R&D in the UK including
Cambridge Display Technology (CDT), Merck, Plastic Logic, Microemissive
Displays (MED) BP Solar, Sharp Laboratories of Europe, Kodak UK
and QinetiQ. There is also some investment in production facilities
within the UK: a plastic hybrid solar cell manufacturer (G24i)
is showing an intention to build a major facility in Cardiff.
However, CDT was recently sold to the Japanese Sumitomo Corporation
and Plastic Logic has moved it production base overseas.
Venture Capital
3.3 Start up companies such as CDT, MED,
Plastic Logic and Molecular Vision benefited from both a supply
of venture capital together with government support; these companies
are now successful multi-million pound enterprises. Those wishing
to attempt to repeat these successes still experience difficulty
in obtaining private funding. Venture capital organisations need
to understand the particular risks and benefits of high-technology
start-ups; an issue highlighted in the Engineering and Technology
Board report Set and the City[22].
Government
3.4 Government has a role to play in providing
funding at a proof-of-concept stage of innovations and also providing
assistance at the technology readiness stages of what is currently
a relatively healthy embryonic industry. This approach has previously
yielded successes such as Plastic Logic and MED. An implementation
of "mission-led" funding and the application of an intelligent
procurement strategy in this area have the potential to encourage
growth.
Whether the UK engineering and manufacturing sector
are set up to handle growth in this area or other areas like it
4.1 The UK is currently not well placed
to fully exploit the domestic strength of scientific research
in the field of plastic electronics. In common with related industries
such as nanotechnology and biooptics, there is an insufficient
number of trained engineering being produced in the UK to meet
current demand within the plastic electronics industry. (In particular
the levels of qualifications and experience required by start-up
companies working in this field often results in them recruiting
staff almost exclusively from overseas.)
4.2 In the case of plastic electronics there
are possible avenues for re-training workers from other electronics
and printing industries to meet demand. However, to date we do
not believe that this has been pursued with sufficient vigour
by government and skills agencies and there is very little awareness
of the issues in universities. The UK must substantially increase
its work force from the present level in order to be competitive
with overseas centres. World-leading companies outside
UK including Sony, Samsung, BASF, Philips, Epson, DuPont, Sumitomo
and Kodak are already producing commercial devices such as full-colour
and single-colour displays for mobile phones, electric razors
and MP3 players and flat screen OLED televisions.
4.3 There are strong growth opportunities
in direct manufacturing in the UK. Given the current predicted
global market revenues, a large number of major international
companies (eg Sony, Philips, Samsung, LG and Epson) are putting
considerable resources into this area to produce the equipment
needed to produce plastic electronics devices. In contrast in
UK there are very few companies working in the area so much of
the equipment may have to be purchased from overseas (although
there are some aspects of high technology printing techniques
in which the UK is very strong). The two UK companies who are
leading this field, MED and Plastic Logic, are currently building
fabrication plants in Dresden, Germany (likewise US firm Nanosolar
Inc. is building OPV fabrication plants in California and also
in Germany). One of the reasons for the attractiveness of Germany
to such high-technology manufacturing companies is the ready supply
of skilled workers.
4.4 Underlying the exploitation of plastic
electronics research and device manufacture is the question of
the market. High quality research work from universities in the
past has been "forced" into markets that may not be
in need or have rather different requirements. To fully realise
the potential of plastic electronics, more thought should be given
to whether the plastic electronics technology really offers the
ideal solutions to product needs. Despite the research strength
in the UK, there are currently not enough proof-of-concept demonstrators
in the field and as such there are serious concerns about the
stability and longevity of the end product. We recommend the Technology
Strategy Board's approach of establishing first the market needs
and then assessing much of this technology sector will meet that
need be more closely adhered to.
March 2008
20 http://www.nanomarkets.net/news/pr-detail.cfm?PRID=195 Back
21
http://www.idtechex.com/products/en/articles/00000640.asp Back
22
Set and the City, etb. 2006 Back
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