Board Thread:Speculation House/@comment-14640999-20140724024429/@comment-10390252-20140727125047

Penny's structure is probably pretty dense (titanium and high-carbon steel), given that she was able to hold down a VTOL. I imagine that the first time anyone who doesn't have a motion semblance like Ruby who tries to pick her up will have a big surprise. That said, I doubt she has much external armour as that would interfere too much with her agility and movement.

So, the outer, flexible layer is probably a composite material like kevlar or mylar that would protect against cutting attacks and light projectiles. The real hardware (CPU and power cells) are probably in armoured boxes in the torso and head and the actual limb struts and joints are probably also made out of heavy combat hyperalloy.

Yes, I'm suggesting that, in internal strucuture, Penny probably looks a bit like a Terminator endoskeleton but with a purely synthetic outer covering rather than vat-grown flesh.