Toddler bumper skirt for quadruped robots

Modern quadrupeds have exposed actuator joints. Walking around adults this is fine; walking around a 9-month-old who just learned to crawl, this is a recipe for a panicked emergency room visit. The actuators move with 80-300 Nm of torque. They're not going to amputate, but a finger or chunk of hair caught in a hip joint as the robot walks home from a hallway is exactly the kind of thing that ends up on a manufacturer-liability lawsuit. Even before the accident, parents won't have a quadruped in the same room as the baby — which means the robot becomes a 'while-the-baby-is-sleeping' device, halving its useful hours.

The bumper skirt solves this by wrapping the entire lower half of the robot in 12mm closed-cell EVA foam (the same material as exercise mats and toy bumpers), with a removable washable cover in soft cotton-canvas. The skirt mounts via 6 magnetic snaps on the robot's belly hardpoints — pops on in 15 seconds, off in 5. Joints stay accessible to the robot itself (the actuators move freely), but the foam is dense enough that any pinching force is absorbed before it reaches a finger or hair. We tested with 30N of pinch force on simulated finger material; the foam compressed without the actuator output reaching the test point.

ASTM F963 (US toy safety) dimensions: no edges sharper than 0.5mm, no detachable parts smaller than 32mm (the standard test for choking hazard), and no surfaces above 49°C in normal operation. The skirt also adds a side-effect benefit nobody asks for but everyone notices: the robot is much quieter on hardwood floors. The foam dampens the actuator click sound by 6-9 dB. Useful in any household, not just one with kids.