Sandfish Lizard-Inspired Wheel Enhances Mars Rover Traction

Researchers have developed a new rover wheel inspired by the sandfish lizard that increases traction and reduces sinking in loose soil, according to reporting from Thomasnet. The design mimics the biological adaptations of the Scincus scincus, a lizard capable of “swimming” through sand, to help planetary explorers navigate the challenging terrains of Mars.

Mars rovers frequently encounter soft, granular regolith that can cause traditional wheels to slip or become embedded. This biomimetic approach focuses on the interaction between the wheel surface and the soil to maintain forward momentum without excessive digging.

The sandfish lizard utilizes specialized scales and body morphology to minimize drag and maximize propulsion while moving through subsurface sand. By applying these principles to mechanical engineering, the new wheel design optimizes the distribution of pressure and the angle of contact with the Martian surface.

According to Thomasnet, the primary goal of the lizard-inspired wheel is to improve the efficiency of locomotion in environments where traditional tread patterns fail. The design aims to prevent the “sinkage” effect, where a wheel pushes sand backward and downward, effectively burying the rover in place.

This development addresses a critical failure point in previous Mars missions. The Spirit rover, for example, became permanently immobilized in 2009 after becoming stuck in a soft sand trap in the Gusev crater.

The new wheel architecture focuses on two main mechanical improvements:

• Reduced Friction: The surface geometry reduces the drag encountered when the wheel pushes through loose material.
• Enhanced Grip: The design increases the effective contact area, allowing the wheel to distribute the rover’s weight more evenly across the sand.

By mimicking the way the sandfish lizard’s scales interact with grains of sand, the wheel creates a more stable interface. This allows the rover to maintain a higher “tractive effort,” which is the amount of pulling force the wheel can exert before it begins to slip.

The integration of biomimicry in space exploration hardware allows engineers to solve complex physics problems by observing evolved biological solutions. In this case, the sandfish lizard’s ability to move through a medium that behaves like both a solid and a liquid provides a blueprint for navigating the Martian regolith.

While the current findings demonstrate improved traction in simulated Martian soil, the application of these wheels to future missions will depend on their durability and weight compared to current aluminum or titanium wheel designs used by NASA.