KU develops an environment-responsive magnetic soft robot

- Next-generation soft robot technology innovation has been achieved, and the robot is expected to be used for environmental monitoring and medical implants.

△ a. A schematic diagram of an integrated magnetic soft robot with wireless multifunctional electronics, b. exploded view of the integrated magnetic soft robot system, c. image of the integrated magnetic soft robot, d. block diagram of the entire electronic system.

A KU research team has developed a magnetic soft robot that monitors its surroundings in real time and responds appropriately by combining a multifunctional electronic system. 

A research team led by Professor Hwang Suk-won of the KU-KIST Graduate School of Converging Science and Technology at KU (President Kim Dong-One) developed a magnetic soft robot capable of reversibly programming various motions, and the results were published online on February 17 in Nano-Micro Letters (IF=31.6), a globally renowned journal in materials science.

*Article title: Wireless, Multifunctional System-Integrated Programmable Soft Robot

*DOI: 10.1007/s40820-024-01601-3

*URL: https://link.springer.com/article/10.1007/s40820-024-01601-3

Soft robots are designed to perform various tasks using flexible and elastic materials, unlike existing rigid body robots. However, their complete autonomy was difficult to achieve because existing pneumatic/hydraulic methods depend on external systems. To overcome these limitations, research is being conducted using stimuli-responsive polymers, but so far they have been limited to simple shape changes and repetitive motions.

Professor Hwang‘s research team first developed a magnetic composite material by coating ferromagnetic particles with soybean wax, which enabled the reversible programming of various motions, even at a low temperature of 45℃. This technology enabled the control of the robot's movements without using high heat energy, thus preventing heat damage.

The research team then overcame the limitations of existing soft electronics systems by precisely combining a thin-film wireless electronic system with a magnetic soft robot. In addition, they optimized the design so that various sensors could operate without impeding the robot’s mobility and functions.

The system designed by the research team is powered wirelessly, and its sensors operate in response to changes in temperature, light, and strain. Using heat and light, it can perform optoelectrical detection and stimulation. In addition, the system can wirelessly transmit measurement data in real time so that the robot can move stably and perform various electronic functions. 

The research team experimentally verified the task performance ability of the developed magnetic soft robot using an artificial obstacle track. The robot effectively navigated obstacles of various shapes and stably performed electrical functions in real time through wireless power transfer. 

Professor Hwang said, “We achieved a functional expansion by overcoming the limitations of existing soft robots. Our robot can be employed in various applications such as environmental monitoring, wearable devices, and medical implants. Our results will provide an important technological cornerstone, especially for the development of miniaturized and advanced next-generation soft robot systems.”

The team’s work was supported by the National Research Foundation of Korea (NRF), the Institute of Information & Communications Technology Planning & Evaluation (IITP), and the Startup Pioneering in Research and Innovation (SPRINT) program.

[Figure 1]  

 △ [Figure 1] (From left) KU Professor Hwang Suk-won (corresponding author), Han Sung-keun (first author, doctoral student at KU), Dr. Shin Jeong-woong (first author, KU), and Dr. Lee Joong-hoon (first author, KU).

[Figure 2]  

△ [Figure 2] a. An optical image of soy wax-coated NdFeB microparticles (WcMPs) (left), and the reprogrammable magnetization process (right), b. behavior depending on the weight ratio of soybean wax and NdFeB particles, c. the magnetic properties of the magnetic soft robot, d. a comparison of magnetization temperatures between magnetic particles formed by coating NdFeB with other polymers and WcMPs, e. the mechanical properties of the soft robot depending on the concentration of WcMPs, f. the magnetic field strength depending on the concentration of WcMPs and the thickness of the soft robot, g. an evaluation of the magnetic soft robot operation depending on the concentration of WcMPs, h. reversible, diverse transformations of the magnetic soft robot induced by an external magnetic field, i. the shape recovery capability of the magnetic soft robot in complex deformations.