Water drop-inspired wheel changes shape in real time to conquer any terrain

Researchers have introduced a new adjustable wheel that can change its shape to move over difficult surfaces.

This novel wheel, inspired by the way surface tension reshapes a water droplet, offers a promising solution for vehicles and robots that struggle with uneven terrains like staircases or large rocks.

Traditional wheels often fall short when faced with such obstacles, either due to their complex nature or their inability to adapt in real-time. The newly developed wheel aims to address these limitations with its innovative design.

Design inspired by water droplets

The key to this transformative technology lies in its ability to switch between circular and flexible states by varying the tension of the wheel’s spokes. Researchers, led by Jae-Young Lee, have crafted a “smart chain” structure that mimics the behavior of molecules within a liquid droplet.

This structure is designed to be reconfigured by inward-directional forces it experiences, allowing it to adapt its shape as needed.

The wheel consists of a chain of blocks spanning its outermost side, each linked by wire spokes to opposite sides of a central hub. By adjusting the gap between the two sides of the hub, the researchers can modify the length of the wire spokes and thus the shape of the outer chain.

Increasing the hub-gap distance shortens the spokes, forcing the chain blocks inward and forming a circular wheel suited for smooth, swift movement.

Conversely, reducing the hub-gap distance lengthens the spokes and loosens the chain blocks. This allows the wheel to deform and adjust to obstacles.

Lee and his team have demonstrated the effectiveness of this variable-stiffness wheel in both a four-wheeled vehicle and a two-wheeled wheelchair. When equipped with these flexible wheels, both systems successfully adapted to large steps and irregular rocks. This demonstrated the wheel’s ability to handle rough and uneven terrains with ease.

Potential for diverse applications

The implications of this technology are vast, with potential applications extending to various fields. According to the research team, this adaptable wheel could revolutionize the way robots and transportation systems navigate challenging environments.

For example, robots designed for search and rescue missions or exploration in rugged landscapes could benefit immensely from such wheels. Similarly, transportation systems intended for off-road use could see improved performance and versatility.

By addressing the limitations of traditional wheels and providing a solution that can adjust in real-time, this innovative design represents a significant leap forward in mobility technology.

The ability to seamlessly transition between different states of stiffness not only enhances the wheel’s performance but also opens up new possibilities for its integration into various systems.

This new wheel technology represents a major step forward in addressing the limitations of traditional wheels.

By incorporating real-time shape-shifting capabilities, this wheel technology enhances the versatility and performance of vehicles and robots. It paves the way for more effective navigation across diverse and challenging surfaces.

The research was published in the journal Science Robotics .