Water Computing Using Superhydrophobic Surfaces

Water droplets colliding on a superhydrophobic surface collide rebound like billiard balls. (Aalto University)

Water droplets can be used to relay digital information because of the way they bounce off each other when on a highly water-repellent surface, according to a new Nordic study.

This property means the millimeter-sized water droplets can act like digital “bits” and could be used to construct simple computers.

The researchers created a chemically modified, silver-coated copper surface that allows water droplets to roll off when slightly tilted. They guided the droplets using specially designed tracks to demonstrate “superhydrophobic droplet logic.”

“When water droplets impact each other while traveling on a superhydrophobic surface, we demonstrate that they are able to rebound like billiard balls,” wrote the researchers in their study abstract.

The team built various systems with the droplets, including a flip-flop memory device, all of which are fundamental to computing. They were also able to control chemical reactions via collisions by adding reactive chemicals to the droplets, with each droplet thus working as both a computing bit and miniature reactor.

“The logic gate that we have developed will never compete in speed with silicon-based logic systems, but they can be useful in other systems,” study co-author Robin Ras at Finland’s Aalto University told TechEye.

“Now we have the first demonstration where we can combine chemistry with such logic systems, because we compute with water droplets, and not with electrons.”

This technology could be used in autonomous simple logic devices that do not need a power source, and biochemical analysis devices for diagnostics.

The findings were published online in Advanced Materials on Sept. 4.

The Epoch Times publishes in 35 countries and in 19 languages. Subscribe to our e-newsletter.