Insect-scale robots created by MIT researchers are quite agile and can traverse some rough terrain, despite their delicate appearance, resembling a cross between a miniature pogo stick and a dragonfly.
Two problems that have faced researchers appear to have been addressed with this version of a miniature hopping robot. Previous versions of tiny robots performed well on flat surfaces, but when it came to uneven or craggy surfaces, they stumbled. And the versions that flew used up too much power too quickly.
This robot features a single, elastic leg with a spring mechanism, like on a clip-top pen, and four tiny wings. It is about the size of a thumb and weighs about the same as a paperclip.
According to MIT News, “The robot can jump about 20 centimeters into the air, or four times its height, at a lateral speed of about 30 centimeters per second, and has no trouble hopping across ice, wet surfaces, and uneven soil, or even onto a hovering drone. All the while, the hopping robot consumes about 60% less energy than its flying cousin. Due to its light weight and durability, and the energy efficiency of the hopping process, the robot could carry about 10 times more payload than a similar-sized aerial robot, opening the door to many new applications.”
Small but Dynamic Robots
The advantage of their tiny size is that they can squeeze into places that their larger counterparts can’t. But there is more to the robot than meets the eye. They are capable of gymnastic-like feats, able to do somersaults, and they can recover from strong collisions. What makes them so dynamic is that they have a fast control mechanism that determines how the robot should be oriented for its next jump. The sensing is performed by an external motion tracking system, and an algorithm controls the next appropriate position. When the robot is in the air, the system determines where its next landing point is, and adjusts for it. It’s a forward-thinking machine; the calculations include the next desired take-off velocity and the position for the next landing. To get to the optimum position, the robot flaps its wings, so that the pogo-like leg strikes the surface at the correct angle and axis and speed. The robot was tested on numerous surfaces, each with a different texture, and it was even tested on a dynamic tilting surface. The robot can easily transition from one surface to another.
Researchers hope to cut the strings on the next version, installing internal batteries and sensors. “Being able to put batteries, circuits, and sensors on board has become much more feasible with a hopping robot than a flying one,” said Yi-Hsuan (Nemo) Hsiao, an MIT graduate student and co-lead author of a paper on the hopping robot. “Our hope is that one day this robot could go out of the lab and be useful in real-world scenarios.”
Earlier this year, MIT researchers introduced an improved version of an insect-like robotic drone that is part of an ambitious effort to develop bee-like swarms capable of taking on the delicate, life-sustaining work of pollination like bees do.
Scaled-down robots have value. They are part of ongoing testing at the University of Tennessee’s Department of Engineering and Technology, where Mahshid Ahmadi, an assistant professor of materials science and engineering, is using them to aid in the testing of a class of materials known as photocatalysts, which could potentially break down common toxic pollutants. The research is critical, because according to the World Health Organization, air pollution causes an estimated 4.2 million deaths annually. That tiny robots would assist, is no small feat.
“Instead of making and testing samples by hand – which takes weeks or months – we’re using smart robots, which can produce and test at least 100 different materials within an hour,” Ms. Ahmadi said. “These small liquid-handling robots can precisely move, mix and transfer tiny amounts of liquid from one place to another. They’re controlled by a computer that guides their acceleration and accuracy.”
Even smaller than tiny robots, nanorobots also hold the potential to improve human health, as a team of scientists, comprised of clinicians from the Shanghai Jiao Tong University School of Medicine in China, and the University of Edinburgh, have developed tiny robots that can treat bleeds in the brain.
According to the University of Edinburgh, the team engineered magnetic nanorobots “about a twentieth the size of a human red blood cell – comprising blood-clotting drugs encased in a protective coating, designed to melt at precise temperatures. In lab tests, several hundred billion such bots were injected into an artery and then remotely guided as a swarm, using magnets and medical imaging, to the site of an aneurysm. Magnetic sources outside the body then cause the robots to cluster together inside the aneurysm and be heated to their melting point, releasing a naturally occurring blood-clotting protein, which blocks the aneurysm to prevent or stem bleeding into the brain.”
Dr Qi Zhou, from the School of Engineering, University of Edinburgh, was the co-leader of the study. “Nanorobots are set to open new frontiers in medicine – potentially allowing us to carry out surgical repairs with fewer risks than conventional treatments and target drugs with pinpoint accuracy in hard-to-reach parts of the body,” Dr. Zhou said. “Our study is an important step towards bringing these technologies closer to treating critical medical conditions in a clinical setting.”
