Zero-energy-consumption magneto-optical storage for next-generation flexible plastic computers

Researchers at the University of Iowa have discovered a method of converting magnetic data into optical data for free, without external electricity. This is a very big step towards flexible, cheap, throwaway plastic computers, which are gaining in popularity due to society’s recent shift towards mobile computing and “quantified self” activity monitors.

Plastic computers are fundamentally very similar to normal, metal computers — but instead of being fabricated out of wafers of silicon, plastic computers consist of organic semiconductors (polymers) that are laid down on a flexible, plastic substrate, creating organic field-effect transistors (OFETs). These OFETs don’t have the same performance characteristics as silicon, but they’re good enough for ultra-low-power mobile and wearable computing. (These are the same kind of organic semiconductors used in OLED displays, incidentally.)

Flexible, organic NAND flash — a few bytes of it, anyway

While we mostly have the logic and computation side of plastic computers worked out, there are still big question marks hanging over the storage and power consumption parts of the equation. OFETs aren’t all that efficient, and current transistor densities are much too low to build usable amounts of RAM or non-volatile NAND flash on a plastic substrate. It is theoretically possible to use a thin magnetic foil that stores high-density data, much like a hard drive platter, but reading that magnetic data with organic semiconductors is hard and consumes a lot of power. Until now!

The University of Iowa researchers have found a way of transducing (converting) magnetic data, stored on a magnetic foil, into optical data emitted by an organic LED. Normally this would require a large amount of electricity, but using a magnetoelectroluminescent compound in the OLED the researchers found that the transduction could be done for free. The science is complex, but from what I can gather the magnetic field of the bits stored on the foil are enough to excite the OLED into producing photons. In theory, you could then transport this optical data around the plastic computer using some kind of communication bus. (Plastics, while not a great substrate for building high-performance computers, are very good at carrying optical data. Most consumer-grade optical fiber, for networking and audio, is plastic.)

. There could also be some implications for high-capacity storage devices that use high-speed optical buses. For consumers, the main takeaway here is that we’re taking another big step towards cheap, flexible computers with decent storage capacity — and given our new interest in curved devices, activity monitors, and sticking sensors on everything, the University of Iowa discovery could be very significant indeed.