How do we tell the difference between a thing and a living thing? We jump at snake-shaped branches. We cry for animated people in Pixar movies, and we feel sorry for, or afraid, of robots in live-action ones. Even if we cognitively understand the difference between “alive” and “unalive,” our emotional understanding is typically more ambiguous. And it becomes more ambiguous when the lines are blurred intentionally.

That’s what I do– I intentionally blur the lines between the alive and the unalive. It takes very little for an audience to begin perceiving life, and we humans can get easily attached to something lifelike without even knowing it. That’s the instinct that inspired the Fur Worm.

The Fur Worm is an experiment in the minimums for the perception of life. With very few motions and sounds, the Fur Worm gets people to feel empathy for its robotic self. If you’re skeptical or curious.

But the Fur Worm is more than just outward biomimicry. It also has a number of biologically-based parts that make its motion, shape, and feel more convincing.

Like this horrifying skeleton:

Fur Worm skeleton by Christine Sunu

The Fur Worm’s skeleton is based off of mammalian vertebrae and knucklebones, a setup that makes it strong and robust. It was so strong, in fact, that I couldn’t break it. A few days before the talk, I had to make a sacrificial vertebrae with a notch cut out of it and even then, the only way to break it was to twist it to the side– the same way you’d break a finger joint or a vertebral section. :-/ As an ex-biologist who did two years of medical school, I have to say this part even freaked me out.

The Fur Worm’s “nerves” run down a ventral spinal column, a biologically atypical design I used to accommodate the shapes of the servos. This gave the wires enough give that nothing would break when it moved around, but also protected the essential connections of the worm from malfunction.

The worm responds to touch by flailing, squirming, and crying. Its “voice box” is in its head, an Adafruit sound board playing the heavily modified sound of a human saying, “Pwee!” Its “muscles” don’t move with a typical servo. Instead, they accelerate in and out of motion, a movement curve that is usually found in living things.

servos for the fur worm [Christine Sunu]

Left: Life-like robot, Right: Robot. These servos were for the Starfish Cat, and I used the same movement principles here.

There are two options for setting off the Fur Worm’s bizarre array of functions. His fur is knit from both soft, fuzzy yarn and conductive yarn. He can sense when he is compressed. He also has a “pressure point” on his tail, to which he will respond instantly by squirming in discomfort.

To pump up the Fur Worm’s cuteness and personality, I added two big button eyes and a pair of 3D-printed horns. And voila! He lives!

Fur Worm by Christine Sunu