Within seconds of the onset of an earthquake, when life or death hung in the balance in every second, such a robot could very well be the difference between the two. This is no science fiction fantasy scenario from a movie but in fact a very real possibility courtesy of the revolutionary work of researchers at Pennsylvania State University. They developed a soft, magnetically controlled robot that is capable of crawling through wreckage to locate survivors or navigating inside the human body to deliver focused therapy.
It is innovation in design: an integration of compliant materials that flow like living things and state-of-the-art electronics mapped along its entire length. Traditional robots are stiff and clunky and don’t do well in cramped and messy environments. To compare, soft robots like one developed by the Penn State team can twist, bend, and crawl with excellent mobility. As Penn State Associate Professor of Engineering Science and Mechanics Huanyu Cheng put it, “We wanted to design a system where soft robotics and flexible electronics work together seamlessly.”
The greatest achievement was addressing the inherent rigidity of electronics, which are hundreds to thousands of times more rigid than the flexible encapsulating materials. Cheng and his team addressed this issue by placing the electronic components within the robot’s structure, but without sacrificing flexibility while still having high-performance capabilities. Magnetic fields remotely guide the robot, with no onboard power or wiring. This technique provides greater flexibility and reduces the likelihood of electrical interference, a problem common with such systems. Cheng is quoted as saying, “Magnetic fields are crucial for controlling motion, but they can also disrupt electronic signals.” We had to carefully design the electronic layout to minimize these interactions.
Uses of this technology are infinite. During crises, onboard robot sensors can detect heat or blockage so that it can move through wreckage and identify trapped victims on its own. In healthcare, the robot can also revolutionize diagnosis and treatment. For instance, it can be designed to react to pH or pressure change to deliver drugs accurately or take samples from remote areas. Cheng also imagines more extreme medical uses, like a “robot pill” swallowed and passed through the digestive system. “Imagine a small robotic system that could be swallowed like a pill, navigate through the gastrointestinal tract and detect diseases or deliver drugs precisely where they’re needed,” said Suk-Won Hwang, co-author on the paper and Associate Professor at Korea University.
Flexible integration is a cornerstone of this type of innovation. Flexible electronics, or flex circuits, are built on flexible substrates like plastic or thin metal that can be folded into several forms without diminished functionality. Such flexibility is necessary in applications to soft robotics, where rigid electronics would prevent motion. As has been witnessed in a study conducted at Yale University, integrating stretchable electronics into soft robots enables them to stretch extensively without losing functionality, a crucial step towards developing functional and practical robots.
Another motivating aspect is the use of magnetic fields to mobilize these robots. Magnetic control systems, as discussed in a review paper study on micro-robots, offer unparalleled precision and safety. Robot motion may be dynamically controlled in real-time by the researchers through regulating the external magnetic field to propel the robot in bending, twisting, or crawling movements. This procedure is not only very agile but also devoid of the discomfort and restriction of traditional diagnostic equipment like endoscopes.
In the near future, Penn State researchers are making the robot smaller so that it can be used inside blood vessels. That vision might allow treatments like removal of cardiovascular blockages or delivering medicine where needed inside blood vessels directly. All such developments can potentially make the role of non-invasive medical therapy safer and more efficient than current methods.
The uses of this technology go far beyond disaster relief and medicine. The convergence of soft robotics and flexible electronics could bring about advances in businesses as diverse as industrial automation and space exploration. Flexible electronics, as shown by the Yale research team of Rebecca Kramer-Battaglia, can add mobility and dexterity to robots so they can traverse difficult terrain and manipulate delicate objects.
Even though the potential for magnetic soft robots is enormous, there are still issues. Conductive but pliable materials, developing effective power sources, and processing redundant information from embedded sensors are still issues. But only the achievements to date serve to put the revolutionary potential of the technology in sharper focus.
The stiff, single-function robot era is giving way to a new breed of soft, multi-function machines. From extracting individuals pinned under a fallen building to delivering medication to save lives deep within the human body, magnetic soft robots are poised to revolutionize the manner in which things can be accomplished with robots. As Cheng so eloquently stated, “That means fewer invasive surgeries and more targeted treatments, improving patient outcomes.“
