Dyta is a Diving-beetle inspired AUV designed and fabricated as a final project for the spring 2019 offering of Bioinspired Design. While observing the swimming mechanics of diving beetles, we noted the ways the setae on their legs fanned out while kicking and fell flat on the recovery stroke. We theorized that this allowed the insect to conserve energy while swimming. We were able to replicate this mechanism using 3d printed parts, fabric, and servo motors.
The design went something like this:
We began by designing the arms. By 3D printing the setae onto small peices of fabric, we were able to create a passive joint between the setae and the rest of the arm. The arm was then designed to stop the setae from opening fully in the opposite direction. As a result, water resistance would fold the setae flat when the arm came forward, and cause them to fan out when the arm moved backwards.
We were pleasantly surprised with the efficacy of this prototype, but with only a week left for the project deadline, we knew we needed to design an enclosure and internal mechanisms fast.
Did you know that Snaplock brand tupperware are waterproof when submerged? At least, during our tests they were.
I acquired two servo motors from the Jacobs Hall Material Store, alongside an Arduino nano, and began to plan the wiring while a teammate 3D printed two variations of a slotted link mechanism to convert the rotation of the servos to linear motion. We drilled holes in opposing sides of the Snaplock, and improvised a rubber seal where the arms connected to the chassis.
With it assembled and functional, it was time to test it. Fortunately the maker-space happened to have a bin just large enough.
It worked.
If you want to read more, here is the paper we submitted about our design.