Printed Electronics – the Missing Fragments
Many other areas of printed and potentially printed electronics are being relatively neglected. Take batteries. Most potential applications of printed electronics call for batteries, preferably of low cost and flexible. The technical requirements vary greatly between the different applications, yet we are stuck with a handful of suppliers who either offer carbon zinc with its limited life, power storage and rate of delivery or lithium technologies with their problems of cost and environmental credentials. (Some would add that lithium is also a fire hazard given what has happened with large lithium batteries in electric vehicles and laptops but the tiny amount of material in a printed lithium battery means that fire or explosion is the least of its problems.) The important question is, “Who is working on the intermediate printed battery technology demanded by the market place?” With large battery technology we have nickel metal hydride for example. For printed electronics we have nothing.
A similar question can be asked about large printed memory – from kilobytes to gigabytes. So few companies are working on this that AMD has about 80% of the patents for potentially printable, thin film versions, yet large memory will be needed for a high proportion of applications involving printed transistors.
Printing of transistors and of photovoltaics seem to have their fair share of the cake, with about 100 organisations now working on each. Several companies promise initial commercialisation one or other of these this year and many are to be on flexible substrates. In particular, the Japanese have moved into overdrive in registering patents relevant to printed transistors in the last year.
One can not be as sanguine about printed sensors, fuel cells or even development of alternatives to printing silver for conductors, fuses, antennas and so on. Too few organisations are working on these aspects.