Wen | ma Jing, an intern of China Science Daily, and a reporter Li Chenyang
Editor| He Tao
Seeing this brown "living" creature deftly rolling two wires together, what do you think it is?
This is a new type of magnetic slime robot, jointly developed by the team of Zhang Li, a professor at the University of Chinese in Hong Kong, and Xie Hui, a professor at Harbin Institute of Technology.
It is conductive, and when it connects two wires, it repairs the interrupted circuit. In addition, it has a lot of magical manifestations.
It can move freely, change shape and drill through narrow seams:
You can also grab objects:
Or transform into C-shapes and O-shapes, enveloping and "devouring" objects:
Even in the case of being cut into several sections, it can repair and heal itself:
Seeing this, did you have a scene from the movie "Venom" in your mind?
Indeed, its development was inspired by Venom. Moreover, because of its appearance and material resemblance to "slime" toys, it is also known as slime robots. The results were recently published in Advanced Functional Materials, the top journal in the field of materials.
PhD students watching Venom saw inspiration
In the field of clinical medical treatment, minimally invasive surgery, targeted drug delivery and other operations are inseparable from micro-soft robots.
There are two main materials for traditional miniature soft robots, one is a solid represented by silicone elastomers, and the other is a functional liquid based on magnetic fluids and liquid metals.
However, practical applications have found that the deformation ability of silicone elastomers is limited, the environmental adaptability of liquid robots is poor, and they face many constraints in the complex human organ environment.
So, is it possible to have a state of matter in between, cleverly blending the environmental adaptability of elastomers with the deformation ability of liquids, so that they can be better used in clinical medicine?
Driven by curiosity, Sun Mengmeng, who was still studying for a doctorate at Harbin Institute of Technology at the time, put forward his ideas to his mentor Xie Hui. "I got my inspiration from the movie Venom and Slime Toys to see if I could use a hydrogel to simulate this state of matter between solid and liquid." Sun Mengmeng told China Science Daily.
In 2021, after graduating from HIT with a ph.D., Sun Mengmeng came to Hong Kong as a postdoctoral fellow at Chinese University and proposed the same idea to his supervisor Zhang Li. Therefore, under the full support and guidance of two professors from HIT and CUHK, the slime robot began to gradually "manifest".
The first is the preparation of mucus, the researchers added magnetic powder and borax to the polyvinyl alcohol solution in turn, and obtained a magnetic slime. The external magnet is then fixed to the robotic arm, and the magnetic field is changed by manipulating the robotic arm to control the movement and stretching of the magnetic slime, while the fluid nature of the magnetic slime itself also helps it better adapt to environmental boundaries.
However, just moving and stretching doesn't seem surprising enough.
"It would be fun to reach out like an octopus brachiopod and roll it back!" In the blink of an eye, Sun Mengmeng stepped forward to randomly pull the slime robot in the elongated state a few times, and unexpectedly, the stretched part was indeed cocked! Surprised, he continued to turn the magnet, and the place where it was cocked was really like an octopus brachiopod, curling inward.
"That's the reconfigurability of slime robots." Sun Mengmeng explained.
Since the magnetic particles inside the slime have a certain residual magnetism (residual magnetization strength) ability, when the permanent magnet is pulled in a certain direction, the magnetic particles will be arranged along that direction to form a gradient uniform magnetic field, then convert the magnetic field into a rotating magnetic field, and the slime robot will naturally curl.
The discovery means that the slime robot's function has taken it a step further – to grab and wrap objects through curling behavior. It turns out that this small blob of slime can not only "move", but also be very flexible!
Extraordinary, continue to light up the skill tree
The visually cool slime robot is more than just fun.
"The Faculty of Medicine of the University of Chinese in Hong Kong has always been at the forefront of gastrointestinal research, and thanks to the cooperation with the Faculty of Medicine, one of our research priorities is how to apply slime robots to the human digestive tract." Zhang Li introduced to China Science Daily.
In the vision of the application of slime robots, due to its small form, soft material, good deformation ability and environmental adaptability, it can move freely in the digestive tract, quickly enter parts that are difficult to reach with traditional endoscopes (such as the small intestine), and will not cause harm to human organs or tissues. At the same time, its curling and wrapping capabilities help remove accidentally swallowed foreign bodies from the digestive tract, enabling non-invasive remote-controlled "surgery".
Simulates a slime robot removing a coin cell battery from the stomach
However, there are still some key issues to be solved to get the slime robot from the lab roll to the clinic.
"The first imperative of the clinic is to ensure safety." Zhang Li said.
Cytotoxicity test results show that the magnetic particles inside the slime robot have a certain degree of toxicity, and if they enter the human digestive tract, this toxicity must be controlled within the range of the human body.
"At the moment we have come up with a solution that wraps a layer of silica around the slime robot, but it needs to be further rigorously verified before it can be actually applied in the future." Sun Mengmeng added.
In addition, they hope to give slime robots the same intelligence as "Venom".
At present, the movement of slime robots also needs to be artificially manipulated by external magnets, but in the dynamic and complex digestive tract environment, human manipulation is obviously inadequate. Therefore, scientists hope to realize the intelligence of slime robots, so that it can make autonomous decisions and execution under the guidance of doctors, "automatically drive" in the digestive tract, and carry out disease diagnosis and treatment unimpeded.
Zhang Li stressed that the stage of slime robots can be more extensive.
"In extreme environments where the human hand and even the robotic arm are difficult to adapt to, such as outer space, larger and stronger magnets can be used to manipulate magnetic objects more remotely. In this regard, slime robots may be able to play to its advantages, especially in some small spaces to operate tasks. He said.
"On the shelf" or "on the shelf", research makes sense
Sun Mengmeng
As the first author of the paper, Sun Mengmeng undertook the overall conception and design of the research. Last fall, Sun Mengmeng came from Harbin Institute of Technology to hong Kong's Chinese University.
The rigorous and pragmatic research atmosphere of Harbin Institute of Technology and the encouragement of hong Kong Chinese University to imagine the imagination have created a good environment for Sun Mengmeng to explore. "Our slime robot is still a preliminary stage of innovation, but we are also pushing in the direction of application on the ground."
This collision of pragmatism and innovation, in Zhang Li's view, precisely reflects the equal importance of applied research and basic research.
"In layman's terms, basic research is called 'on the shelf', applied research is called 'on the shelf', whether it is 'on the shelf' or 'on the shelf', as long as it is done well, I think it is very meaningful." Zhang Li said.
Zhang Li, Professor, Chinese University of Hong Kong
As the Director of the Joint Laboratory of Robotics and Intelligent Systems at the University of Chinese, Hong Kong and the Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Zhang Li has been committed to promoting scientific research cooperation between Hong Kong and the Mainland.
"We have always had a very good cooperative relationship with the mainland, and if we give full play to our respective strengths and actively cooperate, we will definitely be able to occupy a place on the international stage, and for us, this stage will only get bigger and bigger." He said.
Reference Links:
https://inews.co.uk/news/science/scientists-create-magnetic-slime-robot-retrieve-accidentally-swallowed-objects-1553802
https://onlinelibrary.wiley.com/doi/10.1002/adfm.202112508