Snatcher: A highly mobile chameleon-inspired shooting and rapidly retracting manipulator

Chameleon tongue-like manipulators have the potential to be quite useful for mobile systems to overcome access issues by allowing them to reach distant targets in an instant. For example, a quadrotor with this manipulator will be able to snatch distant targets instead of hovering and picking up. In this letter, we present a chameleon-inspired shooting and rapidly retracting manipulator, which is lightweight, compact, and ultimately suitable for mobile systems. To make this possible, two design strategies are proposed: to use a wind-up spring as an energy source and to employ an active clutch to selectively distribute the energy. The wind-up spring enables the device to keep supplying the stored energy for a long time, compared to normal torsion springs. The active clutch controls the direction and the timing of the energy supply, which allows to deploy and retract the end-effector. Thanks to these design strategies, the device achieves snatching manipulation while maintaining compact and lightweight. In result, the Snatcher has a size of 120 × 85 × 85 mm, weighs 117.48 g, and brings a 30 g mass located at 0.8 m away within 600 ms.