Updated: Aug 26, 2019
Authored by Catherine Hodges
Biomimicry: a background
We all know that nature sometimes does it better. For years, humans have been looking to the natural world for inspiration, whether it be in art, architecture, medicine or technology. Termite mounds, for example, have inspired new buildings with increased energy efficiency through improved ventilation systems. Automobile manufacturers have taken information from fish and birds to decrease resistance and increase speed and efficiency of their vehicles. Nature even inspired everyday materials we take for granted like Velcro. Now, scientists are looking to the Earth for new ideas to take into space.
The problem with space
Space, the final frontier. The infamous words spoken by Captain Kirk in Star Trek are true for a very good reason. Outside of low orbit, radiation levels soar and distances to travel to the next nearest ball of gas or rock are huge. New methods of propulsion are needed to traverse these vast expanses, alongside increased efficiency of oxygen and water recovery systems, better energy generators, heat shields, navigation and communication systems. Deep space is an environment stuffed full of hazards for living organisms. So how can nature help provide a solution?
Well, researchers at NASA are using biomimicry to overcome some of the difficulties associated with zero gravity. Designs based on gecko feet were recently unveiled for new gripping technology, intended to help keep small objects in place on the International Space station, help robots stick to the outside of spacecraft on automated missions and for use as space junk grabbers, preventing damage to spaceships by debris.
Geckos have the uncanny ability to walk and stick to almost any surface, due to the unusual structure of their feet. Microscopic hair-like structures called setae cover their surface. These structures split into bristles in the same way that human hair can have split ends. This generates a huge surface area for attractive forces called Van der Waals to occur between the surface and the gecko, holding the creature in place, even if the gecko is upside down on a ceiling!
The team at NASA’s Jet Propulsion Laboratory have been working on a synthetic version of the material. The prototypes have been tested in zero gravity, enabling handling of both a 10 kg cube and 100 kg person. In the lab, the gecko grippers have been tested up to 30,000 times without losing any of their stickiness. Where tape can lose adhesiveness within a few uses, this material will last and doesn’t leave any residue, perfect for space applications. This technology could benefit us here on Earth too!
An alternative example of biomimicry exploits the legs of our eight-legged friends. Spider limbs are slightly different from the legs we’re used to. Where we have both extensors and flexor muscles to straighten and flex our legs respectively, spiders don’t have extensors. Instead, they have a sort of fluid hydraulics system to straighten their legs. The spider body is filled with a blood-like fluid called hemolymph. Muscles inside part of the main body of the animal control the hydraulic pressure and movement of this fluid, forcing the spider limbs to extend by increasing pressure.
Recently, new actuators based on these spider leg systems have been designed for space flight. Actuators are mechanical devices which are used to apply forces, or change energy into motion. In the context of space, these little devices have a multitude of applications, manipulating the orientation of spacecraft appendages like antennae, refocusing scanning equipment and control drilling movements on planets or asteroids. These bio-inspired actuators have a high strength-to-weight ratio, ideal for space flight where weight is crucial.
Taking a tumble
One final source of inspiration can be seen in many old cowboy films. The iconic tumbleweed drifting across a wild west filmset may not immediately bring to mind anything extra-terrestrial, but now researchers are developing new robots which move in the same fashion.
The Phobos Surveyor, mothership for a mission to the Martian moon of Phobos, will deploy numerous small robots nicknamed ‘hedgehogs’ because of their spiky appearance. These small spherical structures will roll about the surface of the moon, surveying factors such as soil composition and detailed topology. Traditional designs of rovers can have trouble manouvering in the low gravity environments due to poor traction of their wheels, so these hedgehogs couple machine-driven propulsion systems with the natural airborne movement of tumbleweeds. Inside the robot, three rotating discs, each oriented in a different direction, cause the robot to move in a tumbling or hopping motion, depending on speed of disc rotation. The hedgehogs are still in development, and there’s a long way to go until a mission to the Martian moons becomes reality. But one thing is clear – by looking to nature, we might just get there a little quicker!
Want to know more?
Check out some of the great info out there on biomimetics and space technology:
Menon, C., Broschart, M. and Lan, N., 2007. Biomimetics and robotics for space applications: Challenges and emerging technologies. In IEEE International Conference on Robotics and Automation-Workshop on Biomimetic Robotics (pp. 1-8). Link
Menon, C. and Lira, C., 2006. Spider-inspired embedded actuator for space applications. AISB’06—Adaptation in Artificial and Biological Systems (Bristol). Link
Ayre, M., 2004. Biomimetics applied to space exploration. WIT Transactions on Ecology and the Environment, 73. Link
Bar-Cohen, Y., 2006. Biomimetics—using nature to inspire human innovation. Bioinspiration & biomimetics, 1(1). Link
NASA also publishes a great e-zine on their latest technological developments every quarter if you want to know more about cutting edge space technology, find it here!