I have been working on the hinge between the main bloc and the footpads, because its shape will dictate our choice of sensor to get the angle between those blocs. I phoned my godfather who worked in the bearing industry, and he recommended using plain bearings. The issue is, there will be quite an important torque applied to the hinge, and only plain bearings can support it. However, I do not know anything about those and have consequently been reading about them here.
I also have chosen the IMU, which will be LSM9DS1.
We thought we had a pretty good motor, but the lady Charles contacted to have the datasheet and reference of the motor only sent useless data, so we would rather find another one, and Alexis provided us with quite a few resources to do so.