The human hand is a marvel of evolutionary biomechanics. With an opposable thumb and four long dexterous fingers held together by 27 bones and 27 joints, it can grasp, clench and twist with extraordinary dexterity and delicacy. Despite decades of innovation, robotic replicas are still no match. Even today’s most cutting-edge metallic fingers fumble at shoelaces and keys.That lack of precision is one of the main reasons the parade of jaw-dropping robotic feats in recent years – from choreographed...