- Capable of changing growth direction by sensing the surrounding environment, expected to be used as an exploration robot

 

An artificial material system that grows like living organisms, changing its growth direction by sensing the surrounding environment, has been reported.

The College of Engineering at Seoul National University (Dean Hong Yu-Seok) announced that a joint research team consisting of the Department of Mechanical Engineering (Professor Kim Hoyoung, Dr. Chanjin Park), the Department of Materials Engineering (Professor Sun Jeong-Yun, Dr. Hae Ryeong Lee) at Seoul National University, the Department of Mechanical Engineering at Ajou University (Professor Jong Hyun Ha), and the Department of Mechanical, Smart, and Industrial Engineering at Gachon University (Professor Geunhwan Park) has developed an artificial material system that mimics the growth of mushrooms.

 

Many living things show the characteristic of changing their growth direction by detecting external stimuli as they grow.

Plants perceive the direction of light and grow towards it, while fungi that form mushrooms detect nutrient-rich areas and grow towards those with abundant nutrients. Plants produce energy through photosynthesis, while fungi proliferate through the nutrients in the surrounding environment. This ability to detect the surrounding environment and change the growth direction autonomously is essential for the survival of organisms.

Cells such as pollen tubes and root capillaries observed in plants and hyphae in fungi all grow only at the tip. To achieve growth only at the tip of cells, specific conditions must be satisfied simultaneously. The joint research team led by Professor Kim Hoyoung of the Department of Mechanical Engineering at Seoul National University announced that they have developed an artificial material system that can mimic terminal growth by utilizing the non-solvent induced phase separation (NIPS) of polymer solutions to satisfy all these conditions.

The polymer solution-based system that grows only at the tip showed the ability to change the direction of growth by recognizing external stimuli such as light, touch, and gravity during growth. The research team stated that while existing systems responding to external stimuli rely on cameras and computers for calculated actions after perceiving the surrounding environment, the developed material system can respond to external stimuli without the need for perception and computation processes due to its structural characteristics.



▲ (From left) StA plant's pollen tube growing through terminal growth, material system mimicking cell growth, and a light bulb turning on when the circuit is completed by using the material system as a growing wire

 

The joint research team also announced that the developed artificial material system can be used as a conduit for transporting other materials. It was reported results of using it as a growing wire to connect severed circuits by transporting liquid metal with conductivity or transporting other liquids that mix well with water without leakage even in water.

As a result, the developed artificial material system can autonomously change its growth direction and explore the surrounding environment, as well as transport materials without external intervention such as humans or computers, and can be utilized as a robot for exploring extreme environments that are difficult for humans to approach in the future.

Meanwhile, the research results were published in the Proceedings of the National Academy of Sciences, a prestigious international journal, on January 3.



▲ (From left) Researcher Chanjin Park of Seoul National University, Professor Geunhwan Park of Gachon University, Professor Seon Jungyun of Seoul National University, Professor Kim Hoyoung of Seoul National University

 

[Inquiries]

Chanjin Park, Department of Mechanical Engineering, College of Engineering, Seoul National University / chanjinpark@snu.ac.kr