Have you imagined a huge machine that assembles cars, data from “Star Trek”, C-3PO from “Star Wars” or “The Terminator”? Most of us would probably think of something massive – or at least human size.
But an entire arm of robotics is focused on bug-sized (and smaller) bots.
It’s not just the size of tiny insects that inspire robotics. It is also the many complex tasks and physical performances that make up the everyday life of many fleas, flies and other six-legged creatures.
The question is not only how big and how powerful we can make a machine, but also how small and well-versed. What could humans be able to do if we could command a tiny army of simple machines? How could we use robots that could fly, glide over the water, jump to the ceiling and even swarm?
This is exactly the question that robotics like Zeynep Temel, assistant professor of robotics at Carnegie Mellon University in Pittsburgh, ask and answer in their laboratory.
Tiny robots would be useful in medical applications – according to Temel for targeted drug delivery or simple operations without incisions. Miniature robots could also save lives in dangerous places like minefields or during search and rescue: “If you have small insect robots,” she said, it is possible to conduct “more efficient and safer rescue operations” after an avalanche or earthquake that involves entering Humans or even larger robots is dangerous.
Small robots that can work together like ants or bees are also great for exploring other planets like Mars and keeping people away from risky, unexplored situations:
“I hope my research will be used to create modular robots that can self-assemble and be used by astronauts in unfamiliar environments to help,” said Jamie Paik, founder and director of the Federal Institute’s Reconfigurable Robotics Laboratory of technology.
These are just a few of the important applications that bio-inspired robots could be used for. That is why robotics in the world’s largest robotics laboratories are dedicated to researching the Insecta class.
Ants are a popular inspiration – they can lift bulky and heavier loads than they are, and move quickly through sandy deserts and forests. These insects also work together to build bridges and overcome obstacles.
Trap ants served as a model for a team that developed a battery-powered, palm-sized robot that “can adapt to an environment and work together,” said Paik, a member of the team. In nature, trap jaw ants do all ant things – and they can snap their powerful jaws at an incredible 90 mph speed to leap away from predators too. Paik and her team used the same mechanics to allow the robots to perform a variety of movements, including “jumping vertically for height, jumping horizontally for distance, jumping somersaults to overcome obstacles, walking on structured terrain, and crawling on flat terrain.” Surfaces “summary of the paper.
Like the ants they are based on, each unit is completely autonomous, but they can communicate through a simple transmitter and thereby work together.
Another perk to tiny, pretty simple autonomous robots? They are cheap compared to a larger robot. “We can throw away multiples of them, and if we lose or break some, they can still do a certain job,” said Paik.
Insect adaptations for high-tech solutions
Why are insects such useful inspiration for robotics? They give scientists a starting point, Paik said, proving what’s possible – like jumping 100 times like a flea, climbing vertical obstacles (or even upside down), or packing full-size wings under a dainty hard one Shell like a ladybug. “These are nature’s optimized designs,” she said.
Temel confirmed Paik’s argument – while she said she was still a bit of a personal fear of insects (the living ones), she still admired how well they solve so many difficult problems.
“They swim, they fly fast, and they know how to balance on perch, they walk and jump on the surface of the water, and they can jump on leaves that are like tiny, unstable platforms,” Temel said.
“All of these movements and movements that we still try in large-scale robotics and (insects) do everything – and they pack everything into such a small space.”
One of the biggest challenges for robots of all sizes is staying upright on complex surfaces. “Robots do well in smooth, but natural terrain is fascinatingly rough and therefore difficult for robots,” said Kathryn Daltorio, assistant professor of mechanical engineering at Case Western Reserve University.
Insects have six legs – or two sets of tripods that think robotically – which are great for stability. In addition to having multiple legs, they also use a variety of structures and materials to move across vertical surfaces. Daltorio researched and mimicked this to create their very simple but successful mini whegs for climbing that only have one motor.
Strength and materials
One thing that humans cannot (yet) accurately replicate is the unique materials that are raised or excreted by insects. Tiny claws, spines, and adhesive pads enable insects to perform their many functions.
Daltorio was able to use man-made materials like Velcro, duct tape, and craft backing for their mini-whegs, but other materials like the lightweight, biodegradable hard exoskeletons are more difficult to reproduce. Currently, according to Daltorio, plastics and carbon fibers can be used to create inexpensive, easy-to-manufacture outdoor areas.
But not all insects are tough, and robotics are now developing soft robots that can change their shape to allow movements like caterpillars instead of relying on legs for any kind of movement. A shape memory alloy can be used that is temperature sensitive so that a soft robot can pucker and roll, but “remember” a stiffer shape when heated. “You can bend them and apply a source of heat and they will bend back – we use that a lot,” Temel said.
Electricity can also be used to change the shapes of special piezoceramic materials. “We apply voltage to bend them one way or another, which is useful for cockroach-inspired robots,” she says.
Speaking of performance, that’s another challenge for small robots. Rechargeable batteries and solar panels are two popular solutions. The RoBeetle uses methanol to contract and expand its laboratory-designed “muscles”.
But just like with materials challenges, this is another area where robotics work closely with colleagues who specialize in materials science, battery and solar technology to work towards autonomous robots. Building a robot is a joint endeavor, Temel said.
There’s a lot more research to be done for robotics before robots are as smart and agile as insects: “Even a small fly has really smart responses that are quick and can respond to a lot of sensory information,” said Daltorio. “(Insects) have this very rich and adaptable behavioral repertoire that we cannot yet use a robot for.”