Printed and potentially printed electronics was first seen as a way of sharply reducing the cost of everything from lighting to personal electronics.That remains an objective. However, it is also proving to be a way of providing electronic and electrical devices that were previously impossible to manufacture. This includes transparent displays, transistors, lighting, loudspeakers, photovoltaics, sensors and batteries.  There are devices working in the terahertz band and very wide area devices such as sensors, ac electroluminescent and other displays and photovoltaics. And they are increasingly deposited on top of each other.  This is leading to components and products that can re-invigorate the following markets:

SECTOR - (Figure relates to global market $ billion)
Conventional electronics - 1,300
Packaging - 430
Silicon chip - 280
Publishing - 200
Electronic displays - 120
Lighting - 65
Cosmetics - 40
Sensors - 30
Photovoltaics - 15

Source: Industry statistics

Little wonder, then, that analysts see printed electronics rising exponentially to around $300 billion in twenty years' time, with the demand for conductive inks alone reaching several billion dollars yearly in little more than five years from now. Little wonder that over 1500 organisations across the world  are now doing major work in this area, about half of them being academic. That is about twice the level of interest and investment of only three years ago and it goes beyond the well publicised organic electronics - indeed, half the materials being developed and used for printed electronics are inorganic. The number of patents in all aspects is sharply increasing as giant corporations down to start-ups announce a raft of exciting new inventions.

The conventional silicon chip is hitting the buffers. Major problems include the cost of the research and development supporting improved production rising exponentially and the cost of silicon factories rising exponentially. This is what Professor Neil Gershenfeld of Massachusetts Institute of Technology calls the Inverse Moore's law. Making small quantities of chips is already very expensive and design and production changes are very slow and expensive. The next step down in transistor size (to reduce cost and provide cleverer circuits) results in short life of the chip. In addition, making chips ever smaller means you cannot subsume large components such as displays, batteries, antennas, microphones etc. They cannot be put on top of the tiny chip so they all have to be connected alongside thus creating something big and unreliable. Printed electronics can get over almost all of these problems but it can also take us into a new world.

Here we have the magic of the new metamaterials, with their negative refractive index and other surreal properties promising previously impossible devices, from the cloak of invisibility to unusually small RFID labels. For example, some metamaterials are flexographically printed to give the necessary microscopic three dimensional patterns over a wide area, such as split ring resonators on microwires.

We now have the reduction in melting point of metals by a factor of ten achieved by  printing them in particles of only a few nanometers across. They can then be annealed on something as delicate as acetate film. What are the new products soon to be launched in biodegradable paper electronics and in electrophoretics where the display uses no electricity until it is changed? The leaders are being eagerly followed as they push the boundaries forward, from tightly rollable electronics and power to edible electronics.