One of the markets firmly in the sights of those developing printed electronics is the improvement in human interfaces such as prompts to take medicine and moving colour advertisements on disposable packages. In the Tom Cruise film Minority Report, this ubiquitous interaction was portrayed as something irritating that would be misused. However, while that makes good cinema, on the day when these capabilities become commonplace, they will more likely be used to enhance brands in ways that consumers appreciate, or they will be rejected. Indeed, in medicine, they will save lives and reduce stress. They have to because the demands of consumers are changing radically for two reasons.
Demanding more and willing to pay
Firstly we are becoming more demanding and we are often willing to pay for something better. We want to know much more about a product before buying it, we demand more help when using it because we are increasingly intolerant of the time taken to interpret instructions, read a notice or advertisement, avoid dangers of cooking, of eating food that is too hot and so on. Fast food is the order of the day. Time is of the essence but we also appreciate novelty, amusement and style. Indeed, nearly all major brands have lost market share to supermarket own brands and they desperately need unique, valued features that cannot be so easily copied, for example because they are patented.
The demographic timebomb
Secondly we have the demographic timebomb where most of the leading nations of the world have declining indigenous populations and immigration is demonised by the press and frowned on by the politicians. The result will be far too many elderly, compounded by the present generation living longer while the birth rate drops. Few realise the stark horror of what will result. The average age of the population of Europe, for example, will rise by ten years by 2015 and then it gets really nasty, with dependent elderly rising to 50-60% of the population so there will be nowhere near enough doctors, nurses and carers to cope let alone earned income to fund pension and care liabilities. Obesity in the young, notably in the USA and UK can only worsen this situation because they will themselves need help with certain movements and many will die young, further reducing the pool of fit earners to cope with the army of dependent elderly.
The sick and elderly will have to do much more to care for themselves. Gone will be instructions that are too small and badly written to be understood without assistance. Where there is static print at present, often in ridiculously small fonts, we shall have moving colour displays that unreel from the package, appear on the wall chart and so on. Products must monitor what we do, help us correct our errors, nanny us in doing even the simplest things. Drugs must be delivered automatically in response to monitored need.
Many people optically challenges today
We can get a glimpse of the task ahead by looking at a few recent statistics. One study has claimed that 100 million Americans already have difficulty reading instructions presumably because they are illiterate, dyslexic, partially sighted, blind or perhaps have a pharmacist that needs to put ink in his printer. We could guess that some do not have the intelligence to decipher badly written text or they are shaking from Parkinson's disease or some other condition and cannot hold the text still. Archives of Opthalmology recently analysed a survey and claimed that a rising number of US people over 65 have one of three chronic eye conditions: it has now reached nearly 50%. Now add the demographic timebomb.
Printed electronics to the rescue?
No one technology or procedure can cope with all this but printed electronics will offer many welcome contributions such as
- Moving colour advertisements, instructions etc cheap enough to be ubiquitous and disposable
- Prompts, instructions, warnings etc by electronic spoken voice and sounds
- Flashing lights on things, even the whole of a package or product lighting up
- Disposable devices that monitor health and diagnose illness by touching the skin or sensing the breath
- Disposable medical instruments that are very easy to use and recors what was done, even radio it to the physician if necessary.
- Wristbands, patches and so on that monitor health and alarm the remote carer or relation as required.
- Roadside billboards with moving colour displays. Reconfigurable wallpaper.
- Wallpaper that doubles as a large television screen.
Many routes for research
Many routes are being pursued in researching possible printed electronic solutions. Thin film transistor circuits are being explored in amorphous and crystalline silicon and with insoluble oligomers that call for vacuum processes but the cruder but cheaper soluble, printable polymer semiconductors have the most proponents - more than the rest put together. However, the crudest and cheapest of all may be the electrochemical printed transistors of ACREO in Sweden that can be deposited onto paper and therefore be biodegradeable. We think they have a place.
There are ways of making a whole package or product light up using printed film and there are even sprayable photovoltaic cells in the Matsushita laboratory in Japan and potentially printable ones at Konarka in the US that can drive these and other displays. Thin film silicon circuits already drive some active matrix moving colour displays commercially and printed polymer transistor circuits do the job, albeit at slow speeds, in the Plastic Logic development laboratories in the UK. The first disposable, low cost moving colour printed display appeared on valentine cards in the UK in 2003 thanks to Dow Chemical spinoff Commotion Printed Display Solutions. These displays do not emit light, their colours are not the best but they only cost 5 cents per square centimeter of active area, they are environmental, flexible and available and proven now. 3-4 cents per square centimetre may be possible later.
By contrast, Organic Light Emitting Diode active and passive displays emit their own light and it is targeted that they will be available on cheap flexible substrates in a few years time with a similar cost per square centimetre of 5 cents. Will power consumption be low enough to make today's printed paper batteries a suitable power source?
Other developers are taking very different routes and this bodes well for the future. For example, the Engineering Department of the University of Cambridge in the UKis developing Liquid Crystal Displays LCDs on flexible substrates but the Japanese are working on flexible ferroelectric displays where the voltages required are something of an impediment. The same can also be said of some electrophoretic displays, where the main work is in the US.
Ten or more companies have thin film low cost batteries launched or imminent and they vary from ones that are very low cost and environmental but have shelf life of only 18 months or so and little power to the lithium types that cost more. Progress is needed but these technologies can still be used far more in their present form.
Loudspeakers and microphones
NXT of the UK and its licensees have laminar transparent loudspeakers and microphones cheap enough to have appeared in Japanese cellphones this year. Use on posters, shelf labels, low cost products, even consumables and packages must follow.
Better thin film capacitors, resistors, inductors, actuators, membrane keyboards, switches and other components are coming along and attention will be directed to making as many of these as possible in one manufacturing process with low cost equipment that is easily reconfigurable. In short, we are getting our toolkit in place. We have had one thousand years of static black and white messages on posters, labels and so on. Then we have had one hundred years of ststic colour on everything. Next comes pervasive advanced multimedia using gigabytes of printed memory yet costing only cents. The world will be safer and more fun as a consequence.