Design of Bio-inspired Gripper Arm for Mars Sample Retrieval

In the last decades, the idea of traveling to Mars has become increasingly popular as technology progresses and the journey is becoming more than just fiction. As a result, existing rovers on Mars are preparing drilling samples of Martian soil for eventual pickup. These soil samples can be located on rough terrain in all orientations and angles and need to be retrieved. The geometry and mass of these samples are predefined, it is cylindrical with a length of 15.2 cm, a width of 2.3 cm, and a mass of 57 g. Traditional gripping approaches focus on opposed fingers, industrial-style scoops, or vacuum adhesion which are very orientation specific and not secure enough for a drone. Our MARS-DOG design acquires sample tubes securely without precision positioning or orientation in a sandy environment. The biomechanical-inspired design is a spring-loaded claw inside a net that closes the gaps between each claw. The net’s aperture is closed with a string on the claw tips. A 3D-printed prototype is capable of picking up, carrying, and dropping a sample tube analog that is at least 57 g, regardless of the object’s pitch and yaw in a dusty environment. Stress-testing the unit revealed a lifting capability of 6 kg which is sufficient for additional sample collection tasks in addition to the original Mars sample tube goals.