Computers and water typically don't mix, but in Manu Prakash's lab, the two are one and the same. Prakash, an assistant professor of bioengineering at Stanford, and his students have built a synchronous computer that operates using the unique physics of moving water droplets.
The computer is nearly a decade in the making, incubated from an idea that struck Prakash 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.
Because of its universal nature, the droplet computer can theoretically perform any operation that a conventional electronic computer can crunch, although at significantly slower rates. Prakash and his colleagues, however, have a more ambitious application in mind.
"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."
The ability to precisely control droplets using fluidic computation could have a number of applications in high-throughput biology and chemistry, and possibly new applications in scalable digital manufacturing.
The results are published in the current edition of Nature Physics.The crucial clock
For nearly a decade since he was in graduate school, an idea has been nagging at Prakash: What if he could use little droplets as bits of information and utilize the precise movement of those drops to process both information and physical materials simultaneously. Eventually, Prakash decided to build a rotating magnetic field that could act as clock to synchronize all the droplets. The idea showed promise, and in the early stages of the project, Prakash recruited a graduate student, Georgios "Yorgos" Katsikis, who is the first author on the paper.