All around the world, engineers are developing robots for a number of applications. This involves building machines that can solve certain problems – fly or swim from point A to B, navigate a maze with narrow walls, grasp and manipulate a soft object, or travel a particular distance with a limited amount of energy. Over millions, if not billions of years, nature has already solved many of these problems. To make biomimetic robots, the engineers study the animal kingdom, figure out how their skeletal structures and muscles work, and then translate them into servos and actuators. The result are robots that are inspired from nature, and are particularly efficient at what they do.
Harvard’s Ambulatory Microrobot, known as the HAMR is inspired by the cockroach, but manages to do much, much more. It can scuttle along the ground like any other cockroach, but it can also walk on the surface of the water. HAMR is a demonstration of how microbots can use the strange physics of the micro scale – in this case, surface tension. The robot is only about the size of a paper clip, and weighs as much too. If HAMR needs to go underwater, it simply applies a voltage to break the surface tension, allowing it to sink. It can then continue to scuttle along underwater. Now the researchers are working on ways to allow the tiny robot to return to land. The same micro scale physics that help the bot walk on water, make it difficult to escape an underwater environment. When HAMR needs to make the transition from underwater to surface, the surface tension acts on it with twice as much force, when compared to when the robot is on the surface. Using soft pads on the front legs of the robot allows the weight of the robot to be distributed, so it can rise from the surface using inclines. The researchers want to give it gecko like sticky pads so that it can just climb out of water.
The Stickybot developed by Stanford engineers, is a robotics platform inspired by the household gecko, and is in its third generation now. The stickybot platform was developed to create a wall climbing robot, one that could attach itself to any kind of surface, from wood, to metal, to glass. A surprising thing about the stickybot shows how the different parts of an animal come together to make it work. One might imagine that all the magic of a wall climbing gecko is in the legs. This is not the case, the tail helps quite a bit to. It is the weight of the tail that pushes the legs to the walls, allowing the gecko, and the stickybot, to maintain a grip. Without this tail, only the front two pads of the robot would be able to maintain its grip on the surface. And yes, just like the real gecko, the tail is detachable! This is not for escaping predators though, it is simply to make the storage of the robot easier. Having a detachable tail means that the utility of it can also be easily demonstrated, when necessary. The researchers intend to increase the rate at which the robot can climb, improving its manoeuvrability, and allow it to move across the wall in various directions
The wheel may be ubiquitous for locomotion, but legs can be a more elegant solution for robots. Robots can navigate extremely complex terrains, and move over obstacles that are larger than them through the use of legs. These kind of robots can help search and rescue operations in hazardous conditions, or in the event of a disaster. The Biomimetic Millisystems Lab at UC Berkeley develop a number of robots known as ambulatory robots, and make them do all kinds of things. Think of them as little cockroaches. The VelociRoach is extremely good at moving its legs at an incredibly high frequency, allowing the 54 gram robot to move at speeds of 4.9 m/s. There are collapsible leg spines on the robot, similar to the structures found on spider and cockroach legs, to increase traction with the surface. A variant, known as the SailRoach, uses a tiny sail mounted on its tail, to provide an aerodynamic steering mechanism. The tiny robot has even been trained to release a micro-aerial vehicle (MAV) to achieve flight.
Bats have among the most complex flying mechanisms in animals. Their wings can change shape during flight, with shoulders, legs, elbows and wrists all moving at once. Translating such complicated flight into a mechanical form was no easy task for a group of researchers at Caltech, but the payoff was worth it. The Bat Bot was a drone weighing 93 grams, and offered more battery efficiency than any other drone of its size. The movement of the flying amplifies the energy of the actuators, requiring them to put in less effort in the first place. One of the tricks that the bats have up their sleeves, is the elastic membrane of their wings. Conventional materials, such as nylon or mylar were just not flexible enough for the wings. The team had to develop a custom silicon membrane for this purpose. Apart from energy efficiency, the batbots have another advantage. Because of the soft silicon used in their construction, they can be used in environments where there are objects or people that can be damaged or hurt if a quadcopter collides into them.
Observing rats for any duration of time might not be something that us regular humans find very interesting. However, scientists will learn what they can from any animal. Rats are nocturnal creatures that do not have very good eyesight. They get around this by using their sense of touch instead. Rats move their whiskers back and forth rapidly, to learn about the environment they are in, as well as the sizes and shapes of nearby objects. Researchers from the Bristol Robotics Laboratory translated this capability into a robot. They started by capturing high speed videos of rats using their whiskers, and tracking each individual whisker. The researchers noticed that the rat was controlling the direction of its nose, to optimise the contact of the whiskers to the surface it was exploring. Then, the researchers developed whiskers out of abs plastic, and started building the robot using 3D printers. Motors were used to move the whiskers, and the collected information was processed by chips on the robot itself. The robot can potentially be used for a wide range of applications – from exploring pipes filled with dirty fluid, to inspecting the quality of textiles.
The oceans remain one of the biggest unexplored domains of science. Every year, there are new species of marine life that are discovered, and many of the ones we do know of, have not been studied and documented. This is because humans and metal robots are not very good at getting close to marine life. Conventional robotic platforms are just not very good at getting close and personal with other life forms. A soft robotic fish, called SoFi, may just be the solution. This robotic fish built by the engineers at MIT does a very good job at looking like just another fish in the ocean. Its undulating movement looks like just another fish, and controlling it is just like playing a videogame, the remote control is a waterproof Super Nintendo controller. The back half of the fish is made up of flexible silicon and rubber, while the front half is 3D printed and contains all the electronics. Because of the materials used, the robot does not have to rely on collision avoidance systems, and can safely collide with underwater obstacles or other life forms. There is a buoyancy control unit on board, that can adjust air pressure, to allow the fish to rapidly rise or sink. The result is a robot that can move in all directions in the ocean, for extended periods of time. At the front of the fish, there is a single camera, and appropriately, SoFi uses a fish-eye lens.
If you remember the robotic bees in Black Mirror, they are already a reality. The tiny drones can be used for a number of purposes other than pollinating flowers. They can be used for environmental monitoring, biological studies, and search and rescue operations. Each bee is about half the size of a paperclip and weighs less than one tenth of a gram. The researchers at Harvard SEAS had been trying to develop the bees for over 10 years, finally achieving first flight in 2013. Since then, the bees have become increasingly advanced, and now have gone much beyond the capabilities of their biological cousins. The RoboBees can dive from the air, into the water, and continue to swim underwater, using the same wings that they use to fly in the air. The flapping frequency of the wings has to change in the two mediums. If the wings beat too slowly in the air, the bee cannot fly, and if the wing beats too rapidly in the water, the wings will break. In the air, the wings flap at up to 300 hertz, while in the water, the flapping speed is a leisurely 13 hertz. Additionally, overcoming the immense surface tension at such small scales, the RoboBee can jump straight out of the water and into the air. At the moment, the RoboBee cannot start flying immediately after jumping out of the water, but the engineers are now trying to give them this capability as well.
Researchers at the National University of Singapore (NUS) have developed an underwater robot inspired by the manta ray. The manta ray is of interest to engineers because of the way they can effortlessly swim through even turbulent seas. Translating this natural solution to a robot allows for efficient and effective autonomous underwater vehicles (AUVs). Developing the MantaDroid was an effort that took two years, and the engineers tried out 40 different fin configurations. Each fin is powered by only one electric motor, and the flexibility of the fins interact passively with the fluid dynamics of the water, to provide additional propulsion. The MantaDroid is fast enough to swim twice its body length per second, and can remain active for ten hours. As compared to conventional propeller based drones, the MantaDroid promises an extended operating period. Potentially, AUVs like the MantaDroid can be used for underwater surveillance. The team hopes to test the drone in the open seas, to see how well it can tackle rough conditions.
The Robird is a drone developed by Clear Flight Solutions, that is good for controlling other birds. The Robird looks and flies exactly like a real raptor would, which makes the natural birds react like they would in the presence of a real predator. The Robird is used to clear runways from birds so flights can take off safely, and to keep birds away from industrial or agricultural areas. There are two Robirds built, one looks like a Peregrine Falcon, and the other looks like an Eagle. The Eagle is an alpha predator, while the Peregrine Falcon is the most common predator across the world. Clear Flight Solutions chooses which Robird to use depending on the local bird population. The good thing about using the Robird is that the bird populations quickly learn that a predator is in the area, and stay away. As the drone triggers the natural instincts in the birds, they do not get habituated to its presence, which happens to other conventional approaches of getting rid of birds (such as kites, sounds and lasers) from where they are not welcome. When combined with the other conventional approaches, the bird control is even more effective.
Europa Squid Rover
NASA has sent a number of rovers to Mars, but when it comes to Europa, they need a totally different approach. The surface of the icy moon is not nearly as interesting as the global subsurface ocean, which may even harbour life. Now, for the robotic probe to function, it needs a power supply, and the solar energy is not that abundant in the remote moons of the gas giant, and definitely even more difficult to harness from within a ocean, below an ice shell. Soft robotics comes to rescue again. NASA is considering sending a robotic squid to Europa, with electrodynamic tentacles that extract energy from locally changing magnetic fields. The same tentacles also allows the rover to move through the water. The same energy and locomotion system can also be used to make the rover move along the surface of the moon, if required. Although inspired from the squid on Earth, the development of the energy technology for the rover had some interesting implications for astrobiologists at NASA. In an environment with little solar energy, what if the local life forms on Europa are powered by electromagnetic energy?
Buy your own biomimetic robots
Do you like the robots on the list and want to get some of your own? There is a line of toys called Hexbugs, which are as much fun for adults as kids. You can choose from beetles, tarantulas, scarabs, fire ants, and more. Some of the bugs are remote controlled, while others have innovative moving behaviour of their own. They will scamper across the room till they run into something, change directions when they detect a collision, or use infrared sensors to prevent themselves from striking a surface. They also display a wide range of locomotion, from wheels, to legs to crawling on the ground like a slug. There are even underwater variants known as AquaBots, that have fish, jellyfish and seahorses. You can build an entire robotic aquarium. While the link is to the international site, these robots should be available at your local toy store.