Reaper Fish


Credit to:
Shuli Jiang, Adriel Luo
September~October 2016


Project Demo


Motivation and Proposal

        We want to build an interesting human-interaction enabled robot but do it in a non-traditional way that only rewards people who are watching it patiently and who have invested time and energy doing so.

        Our idea developed from a motionless rock that does nothing when people can see it but moves when no one notices it (i.e. in the dark). However, a rock, a lifeless object, is somewhat tedious. Therefore, we came up with our second model, an Anglerfish. Like the rock, an Anglerfish lives and moves in a dark environment. With a model based on a living creature, we can explore more of the robot’s behavior and outlook. But Anglerfish often gives people the impression of ferocity, which we don’t want our robots to have. We want a robot that lives and sings blithely in the darkness and is kind of coward sometimes. So we developed our third and final model—-a Reaper Fish, an imaginary fish. The robot interacts with people through a light sensor and a distance sensor. The Reaper Fish reacts to obstacles and light through the distance sensor and the light sensor respectively.



        A Reaper Fish is a famous creature living in the deepest, darkest parts of the sea. It sweeps the sea floor to harvest parts from dead fish for food and growth. When it finds a part, it assimilates that part into itself. Over time, the new part becomes a part of the Reaper Fish. Not only does the Reaper Fish consume the dead parts from other fish for nutrition, but it also preserves the fresh organs and makes them functional again. It learns how to make use of the functional organs and therefore acquires new abilities from the dead fish.

        A Reaper Fish adapts itself to a totally dark environment by two red luminescent eyes that help it communicate with the other Reaper Fish, and a special mouth that receives and sends ultrasonic waves. Sound reflects a Reaper Fish’s mood. When it is happy, it makes sweet tunes. When it is in danger, it screams and its tail will become lightened. Because it lives in the dark, light is lethal to the Reaper Fish. When a Reaper Fish senses light, it reacts violently to light, then freezing and becoming motionless, like turning to stone.


Reaper Fish Vertical View


Reaper Fish Front View

Technical Documentation



Pololu 3pi robot development kit in Arduino IDE


Pololu 3pi Robot x1, small breadboard x1, 2.2v red LED x2, 2.2v white LED x1, 3k-ohm resistor x1

Sensors: light sensor x1, distance sensor x2 (one for decoration only and one for actual purpose), motion sensor x1(for decoration), ultrasonic sensor x1(for decoration)

Laser Cut Board x2

Circuit Design:


Source Code:

Close Look of the inside:


Reaper Fish Double Shell: The bottom transparent shell is to hold the breadboard and the outer dark shell serves as the actual outlook of the Reaper Fish


Close Look

Individual Contribution

Shuli Jiang: Programming, Robot’s behavior development, Video Narration, Documentation.
Adriel Luo: Laser cutting, Distance sensor incorporation, Robot’s music development, Video edition.

Related Work

Knowbotics Research




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