Going Wild With Robots: The Rise of Biomimetics
Artist rendition of EPFL’s Pleurobot. Photo: Konstantinos Karakasiliotis and Robin Thandiackal / BioRob / EPFL.
EPFL’s Pleurobot at a demonstration. Photo: Konstantinos Karakasiliotis and Robin Thandiackal / BioRob / EPFL.
EPFL’s Pleurobot at a demonstration. Photo: Konstantinos Karakasiliotis and Robin Thandiackal / BioRob / EPFL.
The University of Southampton’s octopus robot before being filled with water. Photo: University of Southampton.
The University of Southampton’s octopus-inspired robot can reach speeds of 10 body lengths per second. Photo: University of Southampton.
The Bionic Bird has about 12-minute endurance before needing to recharge by sitting on its egg. Photo: XTIM.
For centuries, humans have built machines to offload work and help accomplish tasks easier, faster and safer. However, these machines were first designed to be application specific and did not contain the variability and flexibility to accomplish a range of tasks. It is also very difficult to build and program something to interact naturally with its environment. Most robots are clumsy and, well — robotic.
Now all that is changing. After stepping away from nature to build rigid metal machines, scientists are looking back to organic creatures as inspiration for advances in robotics. This burgeoning field is called biomimetics, or biologically inspired robotics, and has spawned numerous university programs, specialized laboratories and research journals internationally.
Biomimetic robotics enables researchers to come up with novel solutions to previously complicated machine tasks such as drag reduction mechanisms borrowed from the razor clam or a Ninjabot that can strike quickly like the mantis shrimp.
This approach is particularly useful in regards to motion. Biological motor systems have evolved naturally to suit the environment over one to two billion years. Studies can harness data from this extensive evolutionary process and use them to speed up the development of robotic motion. Researchers use high-speed cameras to study the nuances of animal gait and how the physical features enable such movement.
Recently, a team from École Polytechnique Fédérale de Lausanne’s Laboratory of Intelligent Systems and the Swiss National Centre of Competence in Research Robotics studied locomotion of the common vampire bat, a unique species that can fly and travel along the ground on its folded wings to create an unmanned aircraft that can land and walk. It may one day be able to fly to areas affected by natural disasters and walk through dangerous wreckage to locate victims for rescue teams to focus search efforts.
Biorobotics also helps scientists in reverse as well. By creating mechanical models of natural locomotion, researchers can understand how animals accomplish particular feats. For instance, researchers from Carnegie Mellon University, Georgia Institute of Technology and Oregon University created a mechanical model of a sidewinder snake to understand how the snake could easily climb sandy hills. After using a high-speed camera to study the snake’s locomotion, the team was able to program their robot with a three-dimensional wave motion that replicated the movements of the sidewinder.
“By studying the animal and the physical model simultaneously, we learned important general principles that allowed us to not only understand the animal, but also to improve the robot,” Georgia Tech physics Prof. Daniel Goldman tells Unmanned Systems.
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At the EPFL Biorobotics Laboratory, scientists are perfecting this give and take between biology and its mechanical models. A team has created Pleurobot, modeled after the Iberian ribbed newt, with the Latin name Pleurodeles waltl, using advanced cineradiography to mimic the animal. They tracked 64 points on the skeleton and took three-dimensional X-ray videos to gather data on skeletal movement. The team recorded three different gaits and determined the number and position of passive and active joints needed to reasonably replicate the salamander’s movement.
To best simulate control of each joint, the Pleurobot activates virtual muscles driven by neural network models of spinal cord circuits that aim to match the animal’s recorded movements and maintain realistic viscoelastic properties, like ligaments and tendons.
The project hopes to reveal how the nervous system coordinates vertebrate movement, and with its 27 degrees of freedom, the robot allows for testing with more advanced mathematical models to understand the signals behind locomotion. The lab hopes Pleurobot demonstrates a fast and cost-effective way to produce platforms that can be a physical research interface for neuroscientists, biomechanists, functional morphologists, roboticists, and paleontologists to improve understanding and reasoning behind biological forms, according to the project’s homepage. With the addition of a waterproof skin, Pleurobot may one day also be able to aid in search-and-rescue operations on land over rough terrain and in water.
Eventually, scientists plan on using these methodologies to bring early vertebrates “to life,” allowing the study of many different species, perhaps including extinct species with accurate fossil records.
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Unmanned underwater vehicles may stand to benefit the most from biomimicry. UUVs are notoriously slow movers, with the exception of torpedoes that require large amounts of propellant, that rely on displacing water or using mechanical fins. Both of these methods lose kinetic energy to the surrounding water, whereas fish and cephalopods can make natural use of the water to propel them faster. Marine creatures like the octopus can actually fill their bodies with water and expel it to quickly accelerate.
Scientists from the University of Southampton, Massachusetts Institute of Technology and the Singapore-MIT Alliance for Research and Technology have designed and tested an octopus-inspired flexible hull robot that fills with water and rapidly expels it for unprecedented acceleration and speed. The elasticity and resulting form change allows for 2.6 times more thrust force than with a rigid body.
“This is a proof of concept — an experimental validation of our theoretical and simulation work,” says lead researcher and Southampton lecturer Dr. Gabriel Weymouth.
According to Weymouth, underwater vehicles rarely reach speeds of a single body length per second. His octopus-inspired robot topped out over 10 body lengths per second during testing and will become even more efficient with an increase in size.
“The next stages will be integrating this technology within a more comprehensive soft robot,” says Weymouth. He says that soft robots are ideal for “exploring cluttered environments where maneuvering is critical and collisions need to be non-damaging.”
Imagine using a propeller-driven boat or submarine through a dense area of seaweed: It’s a proper disaster — movement becomes nearly impossible. By taking inspiration from the creatures that live in those environments, researchers can create robots to access places previously inaccessible.
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A large share of biomimetic robotics research and development takes place in universities and research institutions. However, there are private entities taking advantage of the great resource Mother Nature provides.
Edwin Van Ruymbeke, CEO of XTIM, was inspired by the control of real birds and sought to replicate this control in a robotic bird.
“For many years, I worked for the same company as my father and grandfather who together invented TIM, the well-known rubber-band-propelled wing-flapping bird,” says Ruymbeke. “I studied bird flight mechanics as part of my aeronautical engineering course and always dreamed of finding a way to replace the rubber band with a battery-powered electric motor so the bird could be radio controlled.”
Ruymbeke spent four years developing Bionic Bird and its biologically inspired steering system, which uses wing distortion to allow for quick and immediate changes in direction. Also, because of a tail that changes angle, the bird bot can be used inside as easily as outside.
The Bionic Bird, which is controlled through a smartphone app and charges via a magnetic contact on its egg, is upgrading capabilities to include an onboard camera and hovering mode to take clear videos and a tail made from a shape memory bio-metal to allow the flying robot to perform aerial stunts such as loops, super-slow flights and precision trajectories.
According the company, the Bionic Bird is so lifelike that other birds cannot tell the difference and may even join the robot in flight.
Whether scientists and engineers are creating robotic pals for animals, the capabilities that biomimetic robots provide are as endless as the universe itself. If the world has created it, researchers can replicate it to accomplish tasks that have been solved over billions of years of evolution. Likewise, robotics provide a unique insight and an accessible way to study how nature has overcome these obstacles.
