What is alternately called biomimicry or bio-inspiration?across robotics and other industries?could represent $300 billion annually of U.S. gross domestic product (GDP) in 2010 dollars within 15 years, according to the Da Vinci Index, a biomimicry report developed by a consortium that includes San Diego Zoo Global, Point Loma Nazarene University, in San Diego, and the University of San Diego.
Across land, air, and water, nature has evolved a smorgasbord of biological forms and functions, each of which demonstrates a unique set of adaptations to our planet’s environment. Nature enjoys a few billion years? head start on humanity when it comes to design efficiencies, but this does not prevent robotics experts from attempting to capture biological expertise and embody it in robot designs.
Matching the capabilities of nature is ambitious but achievable, as a host of recently developed robots inspired by nature demonstrate, from bats? sonar systems (ChiRoPing) to ostrichs? sprinting ability (FastRunner) to geckos?climbing skills (the Timeless Belt Climbing Platform, or TBCP-II). There?s even a robot modeled after a Venus flytrap.
With nature offering so many adaptations, it’s perhaps no surprise that bio-inspired robots are experiencing rapid growth in both the commercial and research sectors. It?s a trend being driven by more efficient computing tools, government and military investment, and in some cases, closer collaboration between biologists and roboticists. And despite some leveling out caused by the global recession, that growth is set to continue over the coming years as nature inspires roboticists to model biological capabilities for robotic ends.
The Da Vinci Index, which measures number and value of biomimicry-related research grants, scholarly articles, and patents to estimate the extent of the marketplace, also forecasts that biomimicry could account for 1.6 million U.S. jobs by 2025 and represent about $1.0 trillion of global GDP.
With NASA’s help, the consortium behind the Da Vinci Index plans to develop a cluster of 1,000 biologists, other scientists (including roboticists), and entrepreneurs in the San Diego region to help commercialize bio-inspired designs, creating an estimated 2,100 jobs and contributing an extra $325 million to the region’s GDP.
Collaborative hubs like these will combine scientific curiosity with commercial interests, says Lynn Reaser, chief economist at the Fermanian Business & Economic Institute (FBEI) at Point Loma and project lead on the Da Vinci Index. ?Scientific work begins with curiosity and a desire to understand how things work. This creates a battle for closure that leads to discoveries. On the other hand, there are companies looking for solutions to specific problems. We want to form a hub to bring these two groups of people together,? says Reaser. She estimates that by 2025, bio-inspired designs could account for 10 percent of the global robotics market. The consortium expects companies in the hub to see speedy return on investment via collaborative innovations and networking opportunities, market education, and the capacity to move quickly from innovation to commercialization.
With NASA’s help, the consortium behind the Da Vinci Index plans to develop a cluster of 1,000 biologists, other scientists (including roboticists), and entrepreneurs in the San Diego region to help commercialize bio-inspired designs.
Elsewhere, the National Science Foundation is also weighing in on bio-inspired robotics. In September, the Office of Emerging Frontiers in Research and Innovation announced 14 grants for the 2011 fiscal year, awarding nearly $28 million to 23 institutions. Those funds will be used to support four years of research into technologies that will merge biological signaling discoveries with machines that can interact and cooperate with humans. Six of the newly funded projects are specifically aimed at improving designs in prosthetics and robotics.
Perhaps the most obvious example of robotic design imitating nature involves the simple act of walking. On land, animals have successfully adapted their legs to traveling on rough terrain, enabling them to go almost anywhere on earth, including places that wheeled and tracked vehicles cannot go, says Marc Raibert, founder of Boston Dynamics, the Waltham, Mass.-based company that developed the BigDog and AlphaDog robots.
?Because animals have been so successful at this, we thought it would be interesting to build robots with legs, and see if we could make them travel on rough terrain. The legs on our robots take some inspiration from animals, in that they have a sequence of joints and they have springy elements in the legs that try to do what the springiness of tendons and muscles do in animals? says Raibert. ?So, the legs are somewhat bio-inspired, but the engineering is human-made. The materials, bearings, and actuators have lots of differences from animals too.?
The design takes inspiration from the way animals combine sensory inputs from proprioception, or an awareness of how the body?s parts must move in sync, and the vestibular system, or sense of orientation, to actively balance their legs as they move, even when the support base?think claw, hoof, and paw?is small relative to the rest of the body.
?The animal’s sensors and brain determine how to move the legs and other parts of the body to keep the system on its feet as it moves. BigDog and AlphaDog balance themselves too. They have sensors in the legs, a gyroscope in the body, and an onboard computer to calculate how to move under various conditions to keep the robot?s balance as it moves,? explains Raibert.
Ghost in the Machine
Another example of robotics inspired by nature can be found with so-called electric fish, such as the black ghost knifefish that hunt in the muddy waters of the Amazon at night. They do so thanks to their ability to generate electric fields for navigation, object detection, and communication. This ability?and the ghost knifefish?s agility within water?inspired Malcolm MacIver, associate professor of mechanical and biomedical engineering at
The resulting GhostBot is a robot with electroreceptive capabilities and a whopping 32 degrees of freedom. Although primarily created as a tool for scientific research, there is a lot of interest in GhostBot from outside the academic research community, given the system’s potential to provide underwater and surface vehicles with very precise mapping capabilities and augmented sensory intelligence, known as electrosense.
GhostBot, inspired by electric fish, is a robot with electroreceptive capabilities and a whopping 32 degrees of freedom.
?Currently, there isn’t a very good sensory system for near-field use on underwater vehicles. So, iRobot and a number of other companies are very, very interested in having an effective sensory system at that range. That’s exactly where electrosense thrives?in the short-range, near to the body?which is perfect for things like collision detection, collision avoidance, substrate following, and working in highly cluttered spaces around structures like oil rigs,? says MacIver.
The Office of Naval Research recently provided funding for the project, which is being used to transition current engineered systems to real-world applications. ?It holds fantastic promise. We started this engineered approach to electrosense almost 10 years ago, and now other people have started seeing its promise,? says MacIver.
Black ghost knifefish are particularly adept at vertical and backward swimming, making them more acrobatic than other fish. MacIver’s team found that instead of propelling themselves by sending one traveling wave down the length of their bodies as do most fish, they send two synchronized waves?one from tail to head and another from head to tail. ?It’s a super interesting maneuver, which we’ve duplicated in the robot. We’re confident that if we deploy this as a propulsion system on future underwater vehicles, we can get similarly acrobatic maneuvers out of future vehicles,? says MacIver.
GhostBot can deploy forces in many different directions, from very low to very large force values?a capability that’s hard to achieve with a conventional propeller, which has led to commercial interest in its propulsion system. This capability offers opportunities in terms of reducing the threat of entanglement in cluttered environments and enabling up-close inspections of equipment and underwater biological features such as coral reefs without damaging them?something today’s underwater vehicles can’t do very well.
Black ghost knifefish, it turns out, have one more important lesson to teach engineers, which has to do with electromagnetic interference. Gilling and other muscular movements complicate matters for the fish because they interfere with their self-generated electrical currents, potentially impairing their ability to navigate. The electronic components within the GhostBot cause similar problems.
The fish have a special circuit in their brains that helps them learn and cancel out the pattern of electrical emissions that are artifacts from their own movements. It works by adding a negative image of those signals to the incoming sensory signals. Their work on this problem led MacIver’s team to the creation of an innovative, match-filtering noise-elimination technique. While interference occurs on many different frequencies, the robot only emits at a single frequency, making it possible to ignore self-caused interference.
Inspiration in the Air
Meanwhile, in the air, another bio-inspired robot that made headlines (and led to a viral YouTube video) is the Nano Hummingbird, developed by AeroVironment Inc., based in Monrovia, Calif. Designed to provide reconnaissance and surveillance capabilities in urban environments as part of a DARPA-sponsored military research contract, the Nano Hummingbird is a small, lightweight (19 grams) robot capable of lateral 360-degree flips, precision hover flight, and hover stability in 5-mph winds. The device can carry small payloads and fly in both indoor and outdoor environments. It can be controlled by an operator via a live video image stream from the aircraft, without looking at or hearing the aircraft directly, and it can stay in the air for 11 minutes in a single flight.
The Nano Hummingbird also embodies a unique technical milestone?controlled precision hovering and fast-forward flight of a two-wing, flapping wing aircraft that carries its own energy source, and uses only its flapping wings for propulsion and control. ?Nano Hummingbird is kind of like the Wright brothers first flying. It’s awesome because it?s new and completely stunning, but it?s still the first version,? says Matt Keennon, AeroVironment’s Nano Air Vehicle program manager and lead scientist on the project.
The Nano Hummingbird, developed by AeroVironment Inc., is designed to provide reconnaissance and surveillance capabilities in urban environments as part of a DARPA-sponsored military research contract.
The biggest challenge Keennon’s team faced during the project was packing so much technology into such a small form?something nature has perfected over millennia. ?Miniaturizing all of the systems is complex. For example, if you’re going to transmit a high-definition video signal 5 miles, you require a certain amount of bandwidth and power, and you have to source the power whether its solar cells or batteries or whatever. As you get smaller that becomes a problem, because it becomes the dominant payload on your aircraft,? explains Keennon.
He continues, ?It’s gotta be small. It’s gotta be low power. So, it will probably happen first on larger helicopters. They?ll move to onboard systems with visual sensors and accelerometers, gyros, magnetometers, and ultrasound all blended together. It will be more time down the road from that to actually sitting on something as small as our hummingbird, but it can all happen. It’s just a matter of time.?
AeroVironment has a long history of bio-inspired robotics design. In the mid-1980s, the company developed a robotic pterodactyl that later influenced the design of AeroVironment’s fixed-wing UAVs. The Nano Hummingbird was a proof-of-concept project, says Keennon, but it could lead to improvements in the design of smaller aircraft and helicopters.
One trend Keennon has picked up on is that bio-inspired robotic designs are developing more quickly than their more traditionally engineered counterparts. ?Particularly in ground- and marine-based robots, it definitely looks like the efficiencies, the adaptability, the different environments have been increasing more rapidly for the bio-inspired designs than the conventional designs. Conventional tracked and wheeled ground robot designs have kind of plateaued out, but it seems like the walking/running legged robots keep advancing, so that?s kind of exciting to see,? says Keennon.
?Similarly,? he adds, ?the different robotic fish are progressing faster than the conventional propeller or hydroplane or more conventional swimming robot designs. I definitely notice that it might be a similar trend for the flying robots.?
The market for bio-inspired robotics will be driven by consumers, says Keennon. ?I think there’s always going to be a public fascination with the biologically inspired robots. I think that’s why there’s so much fascination over humanoid robots like Honda and Sony compared to more effective robots that are tracked and wheeled that are doing more good in the world,? he says. ?This fascination will always drive the market and help bio-inspired robotics move forward. I think that?s a good thing, because I think it?s going to be a much longer-term process to optimize bio-inspired robotic designs.?
Raibert at Boston Dynamics agrees, saying the growth of bio-inspired designs will be driven by new engineering techniques like 3-D printing and nanotechnology. He says both technologies will enable roboticists to create more sophisticated systems that match some of the complexity and functionality of animals.
For Northwestern University’s MacIver, the biggest future challenges and opportunities in bio-inspired robotics lie in the areas of control and agility. ?When was the last time you rode a whale to North America?? he asks. ?Speed is not a forte of animals, but high maneuverability is. Relative to the length and scales of the body, they can move with great finesse through clutter. That’s something that’s an interestingly difficult about to crack from the robotics perspective.?
The answer doesn’t lie in simply improving propulsion or sensing in robots, but in integrating these functions effectively in a single design. ?The complicated process of weaving actuation to sensors in an intelligent fashion is something animals are masters of and have been since they evolved. We have good sensors. We have good motors. What we don’t have is good couplings of signal processing and motor to make exquisitely agile vehicles. That’s the big future challenge and where things really need to be pressed.?
The omens are good that these targets will be reached: The Da Vinci Index gained a further 5.4 percent during the first and second quarters of 2011 alone, although momentum dropped slightly due to a fall in the number and value of U.S. research grants. Against that, the number of bio-inspired patents has increased and the number of scholarly articles on the subject has continued growing at the same, steady rate since 2007.
Supported by collaborative efforts between biologists and roboticists, it seems fair to say that bio-inspired robotics will continue growing as long as nature continues to inspire.