'Interactive Fish Tank' turns water into a capacitive touchscreen

Feeding fish with fingertips

10

"Interactive Fish Tank" is an installation that explores new, wet boundaries in touch-based interfaces. Developed in 2011 by Manuela Donoso and Crys Moore, Masters candidates at NYU's Interactive Telecommunication Program, the piece effectively turns a bed of water into a capacitive touchscreen, creating a virtual aquarium full of pixelated goldfish.

With "Fish Tank," users can "feed" a swarm of fish by simply tapping their fingers against the surface of the water. This creates a bluish circle around which the fish — represented with orange dots — then congregate. The simulated fish will also follow a user's finger as it sweeps across the water, as demonstrated in the video below.

The idea, according to Donoso, was to create an interactive experience based on a familiar, and somewhat hypnotic pastime "We were inspired by the sense of wonder and curiosity inherent in watching fish swim around in water, as well as the compulsive desire to poke at the fish," Donoso said in an e-mail to The Verge. "With our fish tank, people could poke and prod all they wanted, but without any harm to the fish."

Donoso and Moore aren't the first to explore water-based touch displays, but unlike some previous projects, theirs doesn't involve LCDs or traditional displays. Instead, their animated fish are displayed directly onto the water's surface, using a short throw projector installed at the bottom of the tank. Also included below the tank is an HD webcam connected to a laptop running OpenCV and Processing software. Using OpenCV's blob detection algorithm, the webcam traces the movements of a user's hand, while a customized Arduino circuit board uses capacitive sensing to determine whether or not a finger is in the water.

Once it makes contact with the surface, Donoso explains, a finger "acts in the same way as touching a button on an iPhone or any other touch screen." Indeed, in substituting glass for water, Donoso and Moore present a different, and perhaps more accessible way to understand how capacitive touch works on traditional displays. The underlying principle is the same: a user's touch elicits some change in the surface at the point of contact, and the software reacts accordingly. Whereas smartphone displays gauge this change in terms of electric charge, "Fish Tank" measures it in ripples.

Fishtank_interior

More from The Verge

Back to top ^
X
Log In Sign Up

forgot?
Log In Sign Up

Please choose a new Verge username and password

As part of the new Verge launch, prior users will need to choose a permanent username, along with a new password.

Your username will be used to login to Verge going forward.

I already have a Vox Media account!

Verify Vox Media account

Please login to your Vox Media account. This account will be linked to your previously existing Eater account.

Please choose a new Verge username and password

As part of the new Verge launch, prior MT authors will need to choose a new username and password.

Your username will be used to login to Verge going forward.

Forgot password?

We'll email you a reset link.

If you signed up using a 3rd party account like Facebook or Twitter, please login with it instead.

Forgot password?

Try another email?

Almost done,

By becoming a registered user, you are also agreeing to our Terms and confirming that you have read our Privacy Policy.
Spinner.vc97ec6e

Authenticating

Great!

Choose an available username to complete sign up.

In order to provide our users with a better overall experience, we ask for more information from Facebook when using it to login so that we can learn more about our audience and provide you with the best possible experience. We do not store specific user data and the sharing of it is not required to login with Facebook.

tracking_pixel_5345_tracker