Do you remember the character T-1000 from “Terminator 2: Judgement Day” who was made from liquid metal? Well, that idea has just jumped from science fiction to science journals.
Scientists in South Korea recently developed a “soft robot” that is based on liquid and is able to mimic how living cells act. They hope that the new technology can be used in biomedical applications in the future.
While “liquid” and “robot” might seem like concepts that don’t mix, researchers behind the project decided to take this unlikely approach to solve a longstanding conundrum in robotics.
Biological cells “possess the ability to deform freely divide, fuse, and capture foreign substances,” whereas traditional solid robots have “faced limitations in effectively mimicking the flexibility and functionality of living cells,” explained a Friday press release from Seoul National University College of Engineering.
Professor Ho-Young Kim from the Department of Mechanical Engineering, Professor Jeong-Yun Sun from the Department of Materials Science and Engineering and Professor Keunhwan Park from the Department of Mechanical, Smart, and Industrial Engineering at Gachon University worked to develop the “next generation” robot together. Their work was published Friday in the Science Advances journal.
Instead of the traditional “solid” robots that lack the ability to move like living cells, the team developed something called a “particle-armored liquid robot,” that is “encased in unusually dense hydrophobic (water-repelling) particles.” This design allows the robot to have deformability of liquid and the structural stability of solid.
In a practical sense, that means that the soft robot can recover its shape even after high impact drops – like a droplet of water – without breaking.
Hyobin Jeon, the first author of the paper, explained that the team initially considered “encapsulating a spherical droplet with particles, just as adopted in making conventional liquid marbles,” referring to an existing technology. According to a 2022 article in RSC Advances, liquid marbles are “non-wettable spherical droplets coated with a layer of nanoparticles,” firstly reported in 2001.
“However, by shifting our perspective, we came up with the idea of coating an ice cube with particles and then melting it, which significantly enhanced the stability of our robots,” said Jeon.
Researchers compared it to the liquid robot T-1000 from the 1991 movie “Terminator 2: Judgement Day” and said that it can “pass through metal bars, capture and transport foreign substances, and merge with other liquid robots.”
It can also move feely on water as it does on solid ground. Through their experiments, the researchers found a way to control its movements using ultrasound.
“Thus, the newly developed liquid robot is expected to be utilized in biomedical and soft robotics applications, such as targeted drug delivery and therapeutic interventions inside the human body,” said the press release. “Furthermore, due to its ability to pass through extremely narrow spaces, it could be deployed in large numbers inside complex machinery, between obstacles in rugged terrain, and in disaster zones to conduct exploration, cleaning, chemical-based obstacle removal, and nutrient supply operations.”
Authors of the research said they plan to continue to enhance the liquid robot for broader applications going forward.