Xiaobian actually witnessed the office supplies becoming refined today, and will walk by himself! The telephone line itself will climb, there is a picture with the truth:
The paper clip also seems to have grown legs, striding meteors, walking with their heads held high:
I won't hallucinate anymore, will I? Rub your eyes again, what? It turned out to be a robot.
Although it doesn't look like it on the outside, it is indeed a real robot, a kind of soft robot, and it is not small, this is the latest research result of the Massachusetts Institute of Technology (MIT), in addition to walking, you can swim!
I don't know if you have noticed that this little robot does not have any external cables or equipment when moving, so how does it move freely?
The answer: magnetic fields.
The above is actually ⌈ three-dimensional magnetic soft robot ⌋, combining fiber actuators and magnetic elastomers, using unidirectional magnetic field control, can achieve crawling or walking and other movement modes, but also can be used as a cargo transportation tool, the future can be well applied in complex and difficult to deploy restricted environments.
In addition to the performance of the robot, its production method and control method are also quite innovative, and its scalable ability can even reach the simultaneous manufacturing of more than a thousand robots, solving the current manufacturing problem of magnetic robots!
▍Difficulties in manufacturing and control methods of magnetic robots
In the field of soft robotics, the choice of drive mode directly affects the performance and function of the robot.
Magnetic fields have advantages over light, pressure, heat, electric fields, etc., because the deployment of the magnetic field environment is not bound by anything, nor is it limited by materials, and even weak magnetic fields can penetrate non-magnetic and weak conductive media. In contrast, other actuation modalities such as light, pressure, heat and electric fields cannot penetrate certain substances or require higher energy consumption.
These advantages have inspired a large number of magnetic soft robot research applications for surgery, biopsy, and medicine. Despite this, magnetic soft robots are still challenged by manufacturing and control. To date, they have mainly been formed by two-dimensional structure molding or stereolithography processes, but there is currently no simple, fast and scalable manufacturing method for applications that require more complex three-dimensional structures.
At the same time, in terms of control, most of the current magnetic soft robots rely on equipment composed of multiple magnets or electromagnetic coils, which are complex and bulky, and lack a magnetic field control scheme that can adapt to a variety of robots.
In short, the innovation of manufacturing methods and the simplification of control schemes are the top priorities of current research, and if such a scheme does appear, it can not only enhance the practicality of robots, but also expand their applications in biomedicine and engineering.
▍More than 1,000 at a time, flexible expansion beyond imagination
Having said that, how does MIT solve the problem of manufacturing methods and control solutions in magnetic drives?
First of all, talking about the manufacturing method, it is not difficult to see that the robot like a telephone line has a spiral structure as a whole, which can be regarded as a continuous three-dimensional structure, and the researchers used two elastomers with different deformation capabilities: SEBS (styrene-ethylene-butene-styrene) and COCe (cyclic olefin copolymer elastomer) to combine the two elastomers into a hollow structure, and the inner hollow is filled with a ferromagnetic composite material.
One side of the empty structure is SEBS, the other side is COCe, and then hundreds of meters of thermal stretching, the elastomer can withstand more than 600% of the strain, because the plastic deformation of COCe is larger than SEBS, after hot stretching and instrument treatment, a spiral-shaped structure can be naturally formed.
At this point, a "telephone line" soft robot with magnetically controlled ability has taken shape, but if you want it to move on demand, you must also stipulate its movement method, such as imitating the peristalsis of a caterpillar.
The researchers permanently magnetized the "telephone line", which they placed on a mold and applied a strong magnetic field, so that a soulless "telephone wire" had a caterpillar-like head, body and tail, so that the robot could crawl at different speeds when applying different intensities of magnetic fields.
By changing the posture and position of permanent magnetization, the robot can also achieve bipedal movement. The robot resembles a "paper clip" structure, with two "feet" and one "joint". When standing up and walking with "legs", the spiral coils of the feet are responsible for increasing the contact friction with the ground, and the joints are responsible for stretching the legs in opposite directions.
This is a very flexible way of manufacturing, very scalable and programmable, and for a fixed architecture, multiple robots can be manufactured at scale. For example, multiple segments of magnetic elastic fibers can be stretched at the same time and permanently magnetized in large-volume electromagnets at the same time, making it possible to even manufacture more than 1,000 soft robots in one step, greatly simplifying the development process!
▍Flexible deployment of unidirectional magnetic field
In addition, this structure can also simplify the deployment of the magnetic field environment, only need to fix the unidirectional magnetic field applied by the electromagnet. The "telephone line" robot is in a magnetic field orthogonal to the plane of motion, with sinusoidal changes over time between 0 and 45 mT and frequencies up to 10 Hz.
In the caterpillar's movement mode, when the magnetic field increases, the attraction between the head, body and tail creates a double fold, resulting in a strain that increases the number of folding cycles and crawling speed by changing the frequency of the oscillating field.
The magnetic field environment in bipedal walking mode is slightly different, instead of applying a sine wave, a sawtooth wave is transmitted, and the magnetic field increases from 0 to 23-25mT, and then drops sharply to 0mT, thereby rapidly releasing elastic energy in each cycle.
Using the switching of magnetic fields, it is also possible to load and release goods, or to work together between robots, for example, two robots walking in opposite directions.
▍Introduction of the researcher
The study, published in the journal Advanced Materials, is titled "Magnetically Actuated Fiber-Based Soft Robots."
The first author of the article is MIT postdoctoral researcher Youngbin Lee, who graduated from MIT in 2022, and during his scientific work, Youngbin solved a major engineering challenge to break the axis symmetry of fibers, and will continue to use fibers to build wearable sensors and robots in the future.
In the column of the author of the paper, a familiar name also appeared - Professor Zhao Xuanhe.
Zhao Xuanhe is a tenured professor at MIT under the tutelage of Academician Suo Zhigang, a famous domestic mechanic. Professor Zhao Xuanhe has long been committed to promoting human-computer interaction and convergence technology, and Google Scholar shows that his published articles have been cited more than 17,000 times in total, with an H-factor of 63. At present, the research results of Zhao Xuanhe's research group have had a wide social impact.
This research result is of great significance for the development and application of soft robots, especially in restricted environments, such as surgery, drug delivery and biopsy. Through innovative manufacturing and control methods, magnetic soft robots are expected to play an even greater role in the future, providing new solutions to solve challenges in complex tasks and applications!