A computer that operates using the unique physics of moving water droplets has been developed by an Indian-origin scientist and his team.
The computer is nearly a decade in the making, incubated
from an idea that struck Manu Prakash, an assistant professor of bioengineering
at Stanford University, when he was a graduate student.
The work combines his expertise in manipulating droplet
fluid dynamics with a fundamental element of computer science — an operating
clock.
“In this work, we finally demonstrate a synchronous,
universal droplet logic and control,” Prakash said.
Any operation
The droplet computer can theoretically perform any operation
that a conventional electronic computer can crunch, although at significantly
slower rates. “We already have digital computers to process information. Our
goal is not to compete with electronic computers or to operate word processors
on this,” Prakash said. “Our goal is to build a completely new class of
computers that can precisely control and manipulate physical matter.
“Imagine if when you run a set of computations that not only
information is processed but physical matter is algorithmically manipulated as
well. We have just made this possible at the mesoscale,” Prakash said.
Prakash wondered if he could use little droplets as bits of
information and utilise the precise movement of those drops to process both
information and physical materials simultaneously.
Prakash decided to build a rotating magnetic field that
could act as clock to synchronise all the droplets. Prakash and his team built
arrays of tiny iron bars on glass slides that look something like a PacMan
maze. They laid a blank glass slide on top and sandwiched a layer of oil in
between.
Then they carefully injected into the mix individual water
droplets that had been infused with tiny magnetic nanoparticles. Next, they
turned on the magnetic field. Every time the field flips, the polarity of the
bars reverses, drawing the magnetised droplets in a new, predetermined
direction. A camera records the interactions between individual droplets,
allowing observation of computation as it occurs in real time.
How it works
The presence or absence of a droplet represents the 1s and
0s of binary code, and the clock ensures that all the droplets move in perfect
synchrony, and thus the system can run virtually forever without any errors.
Prakash said the most immediate application might involve turning the computer
into a high-throughput chemistry and biology laboratory.