Mostly she was animated, buoyant, and flexible, her skin was good, and in spite of her white hair she seemed to belong to the world of choice and strength.

NEWYORKER: She��s the One

The shell is flexible and covered in a black leathery skin - hence the name leatherback.

BBC: New law to protect Puerto Rico leatherback turtles

Dennis Hong, a robotics engineer at Virginia Tech, said research into "soft robotics" was part of a wider trend towards designing more flexible and innovative machines, such as his own "Whole Skin Locomotion" (WSL) robotic mechanism.

CNN: Robotics discovers its soft side

These devices use a microcurrent to gently push a drug into the patients skin for faster healing or cosmetic improvements, making a small, thin and flexible battery a necessity.

FORBES: Enfucell Makes Batteries Thin, Green And Printable