The JamHand: Dexterous Manipulation with Minimal Actuation

From using chopsticks to grab items off a plate, to snapping together two LEGO bricks in one hand, common manipulation tasks are easy for humans. However, grasping and dexterous manipulation still rank among the principal grand challenges in robotics. A key challenge is the complex interaction between hand biomechanics and motor control, leading to humanoid hands that remain too complex and costly for use in daily tasks. Here, we bypass this challenge by offering an alternative approach based on multi-finger material phase transition effects. By limiting our focus to dexterous manipulation, we are able to design a robotic hand that can achieve six fundamental dexterous manipulations as well as precision and power grasps, all with only two actuators. We further demonstrate our system on a range of real-world grasping and manipulation challenges. Besides practical application, these results suggest that leveraging the phase transition of granular materials is a viable technique for reducing the hand complexity required for performing daily tasks.