Yoshihiro Shibata first designed the Thunderbolt humanoid robot almost eight years, but it still represents some of the leading edge technology in terms of design and performance, especially its passive walking motions.
One of Shibata’s key design goals was for Thunderbolt to be able to interact with the audience, to give them High-Fives, pickup and throw a ball, play soccer, and even to jump rope.
To do that he needed to incorporate a fully functional gripper for both hands. It had to be low weight and have at least three active fingers. Shibata was able to accomplish the task using only one servo dedicated to the gripper itself.
As you can see from the video, two of the fingers are geared together so they move simultaneously, while the third finger, positioned orthogonally from the first two, moves in sync. All three fingers are driven by a custom linkage designed by Shibata.
In the end, he succeeded in achieving and exceeding all of the original design goals. Thunderbolt is capable of jumping rope (one of the challenge goals for the robots first ROBO-ONE competition), acting as the team leader for his robot soccer team not to mention scoring numerous goals, playing with kids of all ages, and delighting audiences all over the world.