ANTHONY STUART

About the Project

This project was made in collaboration with Ken Nakagaki and the Tangible Media Group of the MIT Media Lab. The device explores the use of running water as a tangible interface to convey data for both practical and aesthetic applications. It consists of ten “blocking modules” powered by waterproof servos that interact with the water membrane formed when water bounces off a smooth surface. Using these modules, a camera, and a micro-controller  the device is able to detect motion from people or objects and change the water membrane’s shape depending on the intended application. Such applications include conveying changing information like a timer, avoiding a person’s hands if the water is too hot, or simply creating familiar aesthetic shapes like a flower or bird.

Design Requirements
The design requirements for HydroMorph were that the device had to be made out of as many transparent pieces as possible so as not to distract from the water, sturdy enough to be transported easily, and have the smallest form factor possible while still allowing the blocking modules to move up and down a total distance of 1.5 cm. These requirements left me with three main design challenges: how to mount the servos to the board, how to arrange them to minimize the device's footprint, and how to minimize height without sacrificing range of motion.

Servo Mount/Placement
I decided to mount the servos to the platform using transparent screws and custom servo mounts, which were 3D printed in clear resin using a resin printer. To keep the servos as close together as possible without the servo horns hitting each other, I mounted the servos at two different levels, one taller and one shorter. I arranged the servos in a circular pattern, with half of the servos slightly closer to the center of the circle and the other half slightly further out. This was done to prevent the linkages from coming in contact with one another. 

Linkages
For the linkages, I used constrained 2D sketches to analyze how the length of the center bar in the linkage affected the angle that the servo horn needed to turn to from its highest position to lower the  blocking module 1.5 cm. This was done to ensure that whatever linkage lengths I chose would still work within the servos confined range of 90 degrees. Once the calculations were completed, the bars of the linkage were laser cut out of clear acrylic and secured to each other with shoulder bolts to reduce friction. 

Results
After 3D painting the servo mounts and laser cutting all of the acrylic, I was able to successfully assemble HydroMorph. A video of it in action can be seen below.