You may have thought the Embody chair was all very high-tech...but it's got nothing on Oki's protoype Leopard chair. It's got a robot-leg in its design. Based on Oki's well-named Robot Leg walking robot, the chair is motorised: when empty it perches up in the air, waiting for your butt to settle against it. When you do so, the leg contracts and winds you backwards and down into an ideal position with "seating comfort akin to being held in someone's arms," apparently.
And when you stand up it lifts itself up behind your behind to aid you getting vertical: assistance you'll presumably need if you're so very relaxed in the chair when seated. I'm not sure how this is different from a regular hydraulic chair mount in practice, however.
Unlike the Robot Leg, which is motorised and capable of jumping, the Leopard chair utilises the geometry of the Leg, but is unpowered. So it won't rise up and start kicking human butt when the robot revolution comes. It is made of carbon fibre, though.
Sadly this material might not make it into the final for-sale product, which Oki is hoping to release in May of 2009. [Tech-on]