COMPUTERS USED TO require entire buildings to operate. Now they fit in our pockets. Similarly, factory-size electronics manufacturing is approaching a contraction. Want proof? Look at that $50 printer on your desk and imagine, instead of using it to spit out a hard copy of that thank-you note, that you used it to print some digital memory.
Not enough memory to power a laptop. Think smaller, like smart tags to inventory all the crap in your workshop. A study published today in the journal American Institute of Physics has a proof of concept for laser-printed memory cells—basically analogous to transistors—onto flexible sheets of plastic and foil. They aren’t ready for prime time, but in the long term, printing your own memory cells could help democratize electronics just like 3-D printers did for hardware.
Depending on your line of work, making these things should only take a fraction of your paycheck. First, there’s the $50 laserjet printer. Then get your hands on some PET foil sheets to print the circuits on—a roll of the stuff will cost you a few bucks, max. The priciest component is the silver ink, which runs between $300 and $400 for a 50 milliliter cartridge. Well, priciest depending on how much you spend on the rudimentary education in electrical engineering you’ll need to design your own memory cell matrices.
Specifically, you’ll be printing resistive memory, a sort of bridge between existing short term and long term memory systems. Traditional digital memory types use transistors—semiconductor-based on and off switches—to store information. Resistive memory is different. “In resistive memory, the logical state is defined by the resistance of each cell, which can be either high or low, representing the 0 or the 1 for binary information,” says Bernard Huber, an engineer at the Munich University of Applied Sciences.
His team didn’t invent resistive memory; it’s been around since 2008. But what’s exciting is that they’ve shown how to make resistive memory so cheaply. Simply download or design the cell schematic (each cell represents one bit, so five lines of silver ink hashed with five perpendicular lines of silver ink gives you 25 bits), load your PET foil substrate, and click print. Compare that to the laser lithography used to make Flash drives—the current standard for long term memory—which takes lots of spinning, heating, and cleaning.
Downsides, there are a few. First, these resistive memory cells aren’t quite long term. “The maximum we got was 1.6 times 10 to the fourth power seconds,” says Huber. That’s about 4.4 hours, for anyone who doesn’t think in scientific notation. Then there’s the endurance factor: Each cell could switch states between 1 and 0 about 1,000 times before wearing out. And desktop printable electronics will never approach the memory capacity to power anything like a laptop.
Which is fine: America needs those high tech manufacturing jobs anyway. But say you owned a brick and mortar store. This technology could let you print out your own tags for your goods, storing all kinds of information about the price, sales status, and so on. Huber hinted at other, more creative applications, like custom brains for simple robots.
In the meantime, Huber and his co-authors are continuing to work out the kinks, and make these cells remember information longer without burning out. Then comes the important part: Printing simple circuits for fun and profit.
