Self-growing like a vine, the soft body extends to every corner;
Or like octopus, the whole body has no rigid structure, just like Dabai in Hero 6;
Of course, there are underwater robots that imitate other fish creatures, and the soft "fins" move flexibly in the water like real fish.
And these seemingly weak and boneless robots are our protagonists today-flexible robots.
What is a flexible robot?
Many creatures in nature have their own flexibility and flexibility. As can be seen from the above picture, the flexible robot actually imitates the shapes of some animals.
Of course, the concept of flexible robot we are discussing is relatively narrow, which means that it is completely composed of flexible materials and has no redundant rigid structure, so the flexible robot must have three characteristics: high flexibility, deformation ability and energy absorption ability.
Zhu Jian, a professor of department of mechanical engineering at the National University of Singapore, also gave a simple concept. The characteristics of flexible robots include the softness of materials, excellent environmental adaptability, super security and good human-computer interaction.
Researchers at Stanford University imitated the growth of vines and invented a new type of flexible robot, which can grow like vines, shuttle through ruins and rubble, find trapped survivors and even bring them water.
Flexible robot "octopus robot"
Researchers at Harvard University have previously demonstrated their latest research results: an octopus-shaped fully flexible robot "Octobot". This kind of robot is made of soft and elastic materials, and it can move by itself without external power.
Professor Tiefeng Li of Zhejiang University and other researchers published an article entitled "Fast Moving Soft Electronic Fish" in Science magazine, and described a flexible robot they developed. Flexible characteristics enable this kind of "electronic fish" to navigate in a narrow space, which broadens the space where they can travel.
Flexible robot based on origami design
Recently, researchers in case western reserve university developed a flexible robot based on origami design.
No matter MIT, Harvard University abroad or Tsinghua and Zhejiang University in China, researchers are looking for a breakthrough in flexible robot technology. It is no exaggeration to say that if we want to meet these characteristics at the same time, there are many technical problems, so this is why the technology of flexible robot has been in the experimental prototype stage.
Can't you be both hard and soft? How to make the robot's body soft and boneless
Why haven't mature flexible robots been put on the market? This has to mention its technical difficulty.
In order to achieve high flexibility and deformability, the materials and driving methods of flexible robots are very particular, and the traditional rigid connectors and shells are completely unsuitable.
First of all, the material of flexible robot should not only be elastic and flexible, but also consider its driving mode. At present, it is common to make the "shell" of flexible robots with 3D printed materials, such as making soft colloidal robots with hydrogels.
Soft robot made of hydrogel.
A research team from MIT made a tentative experiment. They use 3D printing and laser cutting to make hydrogel shell to realize the "flexibility" of "body", and then drive the robot through hydraulic drive.
Then use some special materials to make materials similar to artificial muscles. Electronic dynamic polymer (EAP), shape memory alloy and other materials are all good materials for making artificial muscles. Take shape memory alloy as an example, it can automatically change shape according to temperature, and can remember these shapes to realize actions such as bending, shortening and grabbing objects.
Harvard University has made many breakthroughs in this field. They developed an artificial muscle based on carbon nanotubes, which contains a "dielectric elastomer". When an electric field acts on a soft material, it will deform. However, the electric field strength will be more difficult to control.
In addition, there is a new functional material room temperature liquid metal, which can switch between different forms and motion modes under the action of electricity, magnetism, force and heat. Liu Jing, a researcher at the Institute of Physical and Chemical Technology of the Chinese Academy of Sciences and a professor at Tsinghua University, also wrote in the commentary of Liquid Metal at Room Temperature that "the discovery of the deformable machine effect of liquid metal is expected to lead to a major breakthrough in the theory and technology of flexible machines."
Neither electric drive nor pneumatic drive is a perfect solution.
In terms of driving mode, it can be seen from the composition of materials that most of them are electrically driven. Compared with other driving methods, electric drive has the characteristics of large deformation, high energy density, compact structure, light weight, low price and low noise. However, this driving mode also has great hidden dangers, and it is difficult to control the motion accuracy of the robot. On the other hand, if the electric field intensity required to drive the robot is too high, it will also affect its movement in a certain range.
Of course, there are also pneumatic driving methods. Octobot, a flexible octopus robot introduced by Harvard University mentioned earlier, moves through a simple chemical reaction of hydrogen peroxide decomposition. Hydrogen peroxide as a "fuel" will produce water and oxygen when it meets platinum catalyst. The increase of oxygen will increase the pressure in octopus and will move after repeated switching.
However, compared with electric drive, the moving speed of this method will be slower and the deformation of flexible robot will be limited.
Although the application prospect is broad, it still stays on paper at present.
Although there are many difficulties in the research of flexible robot, it is also a major focus of research and development in many university laboratories, because from a practical point of view, this flexible robot is very suitable for some "extreme" scenes, such as disaster scene rescue: it can enter some dangerous and narrow places; And underwater exploration. Flexible robots can dive into underwater creatures such as coral reefs and explore more underwater secrets without hurting them.
Harvard University Releases Implantable Soft Robot
In medical treatment, flexible robots are also a great weapon. If a doctor wants to prescribe the right medicine for an organ of the human body, it can be achieved through a flexible robot. Franck Vernerey, a mechanical engineer in the laboratory of the University of Colorado at Boulder, developed a soft robot specially used for medical treatment. In addition, in his view, robots used in the medical field can only be constructed in the form of soft peristalsis.
Conclusion:
After briefly combing the concept of flexible robot, Meikejun is very much looking forward to the revolutionary changes that its application will bring to our lives. Many laboratory cases listed in this paper also show that the research on flexible robots has been going on. Over time, waiting for the maturity of related technologies will surely shine in the robot industry.