Move Over Electrons, This Computer Runs On Drops Of Water

Imagine a chemistry laboratory the size of a postage stamp. Thousands of beakers, each no bigger than a poppy seed, conducting thousands of reactions under the careful control of an external operator. This may soon be a reality thanks to engineers at Stanford who have developed a novel method of computing by manipulating the flow of water droplets through a circuit. This opens the door to a brand new field in which computers not only process information, but simultaneously manipulate physical matter.

A new type of circuit: this novel circuit relies on magnetically manipulated droplets of water. Image: screenshot from video below.A new type of circuit: this novel circuit relies on magnetically manipulated droplets of water. Image: screenshot from video below.

The work is the brainchild of Stanford bioengineer Manu Prakash who wanted to take advantage of his specialization in fluid dynamics to produce a new type of synchronous computer. The most important aspect of a synchronous computer is the computer clock. Without realizing it, we rely on computer clocks constantly – in our smart phones, airplanes, even the internet. Any computer system that requires events to happen in a particular order requires a precise clock to start and stop the action. The importance is even greater when multiple actions are being carried out simultaneously.

Traditional computers use a flow of electrons, rather than a flow of water, so the clock consists of an electronic oscillator. The challenge for Prakash’s team was to devise an equivalent for the liquid system. Their solution was to infuse the water droplets with magnetic nanoparticles, thereby allowing a rotating magnetic field to act as the clock. The circuits on the chip were made up of tiny iron bars (essentially mini-magnets) arranged into a sort of maze. Switching the magnetic field changed the polarization of the tiny bar magnets and thus guided the droplets on various routes through the maze. In any given location on the chip, the presence or absence of a drop is taken as a “0” or a “1” in binary code and real-time recording allows any computation to be monitored as it occurs.

By changing the pattern of iron bars, the team demonstrated that all the universal logic gates typically used in computing can be generated. And the perfect synchronicity afforded by the clock means that the system can run virtually forever without error. It is also easily scalable, an important consideration in computing where many chips need to work together in a reasonable area. Both the iron bars and water droplets can be shrunk and the magnetic field can readily manipulate millions of water droplets.

Of course, an astute reader might now be wondering why such a computer is valuable. Clearly electrons move much faster than water, if anything, we should be moving in the opposite direction – computers that run on something faster than electrons: light. That too is a work in progress, but what is interesting about the current system is its ability to manipulate actual physical matter while computing. For example, this computer could act as a high-throughput chemistry lab with each droplet acting as a tiny beaker and carrying a unique chemical. This will be a boon to industries like pharmaceuticals, where often the best means of finding a new drug is to synthesize and test hundreds of compounds.

Admirably, the team has made all of the work open source, encouraging other researchers and budding scientists to design their own circuits for their own unique purposes. It will be therefore just a matter of time before we start seeing the true potential of this new computational method.

Via Science Daily, Stanford University and Nature Physics.