The finger wearable device. (a) Outside view; (b) Schematic of the mechanical design. 1–7 are seven moving links: 1 is the distal phalange, 2 is the intermediate phalange, 3 is the proximal phalange, 4 is a linkage, 5 is the L-shaped rigid rod, 6 is a linkage, 7 is the sliding block; A to I are nine pairing elements: A, B, and C are finger joints, D, E, F, G, and H are revolute pairs, I is the guide rail.