RFID (Radio Frequency Identification) is a system of remotely storing and retrieving it using devices called RFID tags/transponders. An RFID tag is a small object, such as an adhesive sticker, that can be attached to or incorporated into a product that contains a unique identifier. The RFID transponder then read the tag wirelessly via radio frequency. You've most likely to have come across them as anti-theft tags on DVDs in the form of a square sticker that has a spiral shaped metal foil inside, cards you hold up against a reader to access secure areas (ex: buildings, parking lots, rooms, etc), or electronic highway toll payments (ex: EZ Pass, FasTrak, I-Pass, etc). RFIDs are currently being researched as a potential replacement of UPC (Universal Product Code) barcodes. The idea being that if every item in a store/warehouse had a RFID one could in theory have a real time inventory of what is on the shelf/warehouse and what needed to be stocked/reordered. The biggest constraint keeping retailers from using RFID at the moment is the cost, currently a RFID tag costs about $0.40 each. Ideally if the cost dropped below $.05 it would become more economically viable and adopted.

This is where Organic (in a chemical sense: containing carbon) Semiconductors come in. In 2000 Alan J. Heeger, Alan G. MacDiarmid and Hideki Shirakawa were awarded the Nobel Prize in Chemistry 2000 for developing a polymer that could conduct electricity. Until then it was accepted that plastics were electrical insulators, hence they are used in insulating wires. Until this discovery semiconductors were limited to rigid crystalline inorganic materials, which must be extremely pure, and require very precise processing under highly demanding conditions. Many different firms are heavily investing in research of organic semiconductor technology so that the most expensive part of RFID manufacturing, the copper and silicon semiconductor, could be replaced and a cheap RFID could be achieved.

Now, why am I posting this on an environmental new blog you ask? Because of the new and exciting developments in organic semiconductor technology called Electronic Ink. Imagine if you will an extremely precise inkjet printer that instead of regular ink could print using an organic semiconducting polymer. In theory one could print out a RFID or any other number of electronics directly onto paper. Besides RFID tags there are a whole host of other consumer electronics that are currently being developed such as Organic Light Emitting Diodes (OLEDs).

Just as RFIDs could be printed this same technology can be used to print OLED screen/monitors that could produce full spectrum color images at a resolution akin to current "flat" screens made from Liquid Crystal Displays (LCDs), except instead of being a couple inches thick it could be paper thin. LCDs are a liquid crystal matrix of molecules that curl and uncurl when different voltages are applied to them, thus allowing different frequencies of light (colors) through. However this operates as a filter which reduces the amount of light let through and constricts the viewing angle. OLEDs on the other hand would directly emit light when voltages is applied to the organic semiconductor. The advantages would be that the pictures could be brighter, have a wider viewing angle, and require less energy (since only the specific OLED you want lit would need power as opposed to LCDs that require the whole screen to be lit and the entire matrix to be blacked out except the one pixel you want to see). Furthermore LCDs are brittle and difficult to manufacture to larger sizes while OLEDs could be printed to any size and flexible. One could literally roll up a poster size (or larger) OLED screen and mail it in a cardboard tube.

Still confused as to what the environmental ramifications of this technology are? The biggest advantage is that this is an "additive manufacturing process". The current technology used to produce everything from computers to digital watches is "subtractive", first a pure copper/silicon board is created and then unwanted copper is removed to create the circuits. This results in a huge amount of wasted materials and energy spent in creating the pure board which can be avoided by using electronic inks. Then there are the benefits of having a completely digital process for rapid development/prototyping directly from your desk (reducing the amount of time and energy required to develop newer technologies), a potentially recyclable end product (that is free of heavy metals and other toxins), and the reduction of waste going to landfills when the product is thrown out. While I doubt that any of us will be making origami robots at home anytime soon, it will be interesting to see this technology develop and become part of our lives over the next few years.