Saul Griffith's moonshot idea revolves around simple, soft, inflatable mechanisms. He’s got a great example of large inflatable rideable robots.
https://www.solveforx.com/moonshots/solve-for-x-saul-griffith-on-inflatable-robots
According to Saul, engineering design has been following Hooke's Law throughout all of history, but only using the elastic region of the stress-strain curve. Current robot components are heavy and large, limiting speed and motion.
Soft / inflatable materials by contrast are lighter, faster and can be remarkably strong.
The core concept of the solution involves manipulating and constraining the air pressure in flexible materials. The idea is already present in nature - Saul compares a bluefin tuna and a shark. The tuna's tail wing is bony but the shark's cartilage is lighter and stiffer. The shark can tune its stiffness to swim fast at high pressure and be very maneuverable at low pressures.
Griffith shows examples of soft engineered robots gripping eggs, walking under walls, and pumping blood through a heart.
https://www.solveforx.com/moonshots/solve-for-x-saul-griffith-on-inflatable-robots
Griffith and his company Otherlab are working on several projects that are borne from huge ideas.
One part of his presentation starts with conceiving an exoskeleton for superhuman strength and ends with prosthetics, aiding stroke victims and lessening spinal cord injuries. The aging population can benefit from soft external muscles.
Saul shows that an inflatable vehicle, he calls it an electrified wearable airbag, is the most fun to use when you're crashing into things with it.
The most striking idea shown in this Solve for X talk is the inflatable robot arm that moves with near-human fluidity and feels much more authentic than any previous machine interactions.
http://cyberneticzoo.com/wp-content/uploads/inflatable_robot_arm_5-x640.jpg