'Ultralight and High-Strength' New Material Developed… KAIST Expects Use in Car and Aviation Fields

by Jeong Ilwoong

Published 18 Feb.2025 07:53(KST)

A KAIST research team, in collaboration with an overseas research group, has developed an ultralight and high-strength new material utilizing nanostructures. This new material is characterized by maximizing lightweight properties while maintaining high stiffness and strength, and it is expected to be widely used in industries such as automotive, aerospace, and mobility through customized design.

KAIST announced on the 18th that the research team led by Professor Seunghwa Yoo from the Department of Mechanical Engineering collaborated with Professor Tobin Filleter’s team at the University of Toronto to develop a ‘nano lattice structure’ that maximizes lightweight properties while maintaining high stiffness and strength.

(From left) Professor Seunghwa Yoo, Professor Tobin Pheletter, Dr. Jinwook Yeo, Dr. Peter Selles. Provided by KAIST

During the research process, the team focused on optimizing the beam shape of the lattice structure to maximize stiffness and strength while maintaining lightweight properties.

In particular, they performed optimal design considering both tensile and shear stiffness improvements and weight reduction by utilizing a Multi-objective Bayesian Optimization algorithm. Through this, the team demonstrated that the optimal lattice structure could be predicted and designed with fewer data points (400) compared to conventional methods.

The Multi-objective Bayesian Optimization algorithm is a method that finds the optimal solution by considering multiple objectives simultaneously, allowing efficient data collection and result prediction even under uncertainty while iteratively optimizing.

The research team maximized the effect of improved mechanical properties as the size decreases at the nanoscale and realized an ultralight, high-strength, and high-stiffness nano lattice structure using pyrolytic carbon material. Pyrolytic carbon is a carbon material obtained by decomposing organic substances at high temperatures, known for its heat resistance and strength, and is used in various industries such as semiconductor equipment coatings and artificial joint coatings.

To implement the nano lattice structure, the team applied two-photon polymerization technology (an advanced optical manufacturing technique where polymerization occurs only when two photons of a specific wavelength are simultaneously absorbed using a laser beam) to precisely fabricate complex nano lattice structures. Mechanical performance evaluations confirmed that the structure possesses strength comparable to steel while maintaining the lightweight properties of styrofoam.

Professor Seunghwa Yoo stated, “This technology has made significant progress in developing new materials that simultaneously achieve ultralightweight and high strength by solving the stress concentration problem, which was a limitation of conventional design methods, through a three-dimensional nano lattice structure. The technology developed by our team is expected to meet the lightweight demand in the automotive and aerospace industries and open possibilities for broader applications across various industries through customized design.”

Meanwhile, this research was conducted with support from the Multi-phase Materials Innovative Production Process Research Center project (ERC project) funded by the Ministry of Science and ICT, the M3DT (Medical Device Digital Development Tool) project of the Ministry of Food and Drug Safety, and KAIST’s international cooperation projects.