Some of you know I have a biology background, and nowhere does that show more than in the design of lifelike critters. I’m pretty serious about biomimicking robocritters being close-ish to actual biological organisms in terms of layers, since people feel the inside layers of your bot when they pick it up. There is really no amount of stuffing that can turn a square enclosure into a correct-feeling animal skull, ribcage, or body, even though people certainly try.

^ It’s like my teddy bear swallowed a box :(

As long as you have access to the right tools and materials, why not design a better skull, a better skeleton, a better body?

I usually mock up the skull in CAD and 3D print it, lasercut some pieces for speed and ease, and create nice squishy layers using foam, silicone, or wire wrap.

Sometimes the result is cartoonish, like what you’d expect if you were drawing the skeleton of an Adventure Time character:

^ the skeleton of the HaRoCo-1, you've seen this one. 3D printed skull with foam padding around the pettable body, enclosing an FSR to detect pressure.

Other times it's more realistic, based on the skulls of actual critters:

^ the skeleton in Yorick, a fishy seal critter. Head based on an ermine skull, 3D printed, with paint-on silicone enclosing small layers of homemade soft FSRs

For the HaRoCo-12, I’m trying to focus on non-aggressive, adorable animals as the model. I’m starting with the cartoon-skull method, with the intention of making a more realistic skull later. But the really nice thing about this skull is that it contains lasercut struts that allow us to rapidly replace the size and type of motor or servo. So we can experiment rapidly and check out what works best.

Personally, I think this is too much solid matter and not enough room-for-fluff. But it’s not a bad start, and it will give us the opportunity to see how the critter looks with the eyes set more vertically on the head.

I'll post an update when this little bot has some moving eyebrows.

Until next time!