In the yearly nineties, Mark Weiser, a chief scientist at the Xerox Palo Alto Research Center (PARC), introduced the concept of Ubiquitous Computing. Accordingly to Weiser, computers require too much attention from the user, drawing his focus from the tasks at hand. Instead of being the centre of attention, computers should be so natural that they would vanish into the human environment. Within this vision, computers, and others digital technologies, are integrated seamlessly into everyday objects and activities, hidden from our senses whenever not used or needed. Computers become not only truly pervasive but also effectively invisible and unobtrusive to the user.
The work undertaken in this research project pursues this vision. It explores how the concepts behind printed electronics and electrochromism can be used to seamlessly merge the physical and digital worlds. Common printing techniques, such as screen printing and inkjet printing, are used in combination with conductive and electrochromic functional inks as a mean to introduce electro-optic functionalities into objects and products where it was previously unavailable, and thus create simple, embedded, computational structures and digital display devices with novel form factors (e.g. paper based displays). Whereas conductive inks are used to mimic the function of electrical wires, connecting the different electrical components to one another, electrochromic inks are employed to transform lifeless objects and surfaces into dynamic displays (electrochromic displays).
It is expected that the use of printing technologies for the production electronic systems will not only contribute to the incorporation of digital display devices into the most various objects, creating new products and new ways to experience and interact with digital information, but as well enable their mass production at a very low-cost. Electrochromic based displays are used here, as these present some distinctive features particularly relevant for the production of low cost, low power consumption display devices. The structural simplicity of electrochromic displays and the easiness which they are manufactured, together with the nature and availability of the raw materials used to produce this type of displays, makes them very well suitable for mass production. Indeed, the costs are expected to be low enough to render them practical for single-use applications. In addition, the displays are bistable and the average power consumptions are sufficiently low to enable their operation with small batteries. Also, electrochromic displays can be manufactured and assembled under normal environment conditions, not requiring special installations. Electrochromic displays are also characterised for having a high reflectivity and a high contrast, presenting the same agreeable readability as printed paper, whether in direct sunlight or in dimmed light.