Research

Topology optimization has the potential to discover novel structures with outstanding performance that may not be obtained through conventional design approaches. However, the superior performance predicted by numerical optimization is not always reproducible in experiments or practical applications. One of the major challenges is that optimized structures can become excessively complex and difficult to manufacture. In addition, structures composed of multiple disconnected or assembled components may exhibit high sensitivity to the relative positions and connections between components, which can significantly affect their performance.

To overcome these manufacturing and structural challenges, our laboratory investigates methods for incorporating geometric constraints into topology optimization. We develop constraint-handling strategies, mathematical formulations, and adaptive parameter control approaches that enable the generation of high-performance structures while maintaining manufacturability, robustness, and practical feasibility. Through these approaches, we aim to bridge the gap between computationally optimized designs and realizable engineering structures.

Optical cloaking is an advanced technology that aims to control the propagation of light and make objects invisible by guiding electromagnetic waves around them. When light waves are smoothly redirected around an object and restored to their original paths, the object becomes difficult to detect because the disturbance of the surrounding optical field is minimized. This concept has attracted significant attention as a promising approach for manipulating electromagnetic waves and realizing novel optical functionalities.

Inspired by the concept of optical cloaking, similar strategies have been extended to various physical fields, including mechanical, thermal, and acoustic systems. In these approaches, the distribution of materials and structures is designed to control the propagation of physical quantities, such as stress, heat flux, and sound waves, enabling objects to become “undetectable” with respect to specific physical phenomena.

Our laboratory develops advanced cloaking structures for multiphysics applications and multifunctional realizations by integrating topology optimization with advanced optimization algorithms, accurate structural modeling, and effective constraint-handling strategies. These integrated approaches enable the exploration of complex design spaces and the discovery of innovative structures that satisfy multiple performance requirements while maintaining practical feasibility.By applying topology optimization to optical, mechanical, thermal, and acoustic cloaking problems, we aim to establish systematic design methodologies for creating high-performance and multifunctional cloaking devices.

These studies contribute to the development of next-generation materials and structures with unprecedented capabilities for controlling physical fields and realizing novel functionalities beyond conventional design approaches.

For more information, see:

Applied Physics Letters Vol. 102 (25), p. 251106 (2013) | Applied Physics Letters Vol. 112 (6), p. 061108 (2018) | Applied Physics Letters Vol. 115 (17), p. 174101 (2019) | Applied Physics Letters Vol. 118 (10), p. 101102 (2021) | Optics Express Vol. 30 (4), pp.6090–6106 (2022) | International Journal of Heat and Mass Transfer Vol. 242, p. 126834 (2025) | International Journal of Heat and Mass Transfer  Vol. 261, p.128561 (2026)

Location camouflage is an advanced physics manipulation concept that aims to make the apparent location of an object or a physical source different from its actual location by controlling the spatial distribution of physical fields, such as waves, heat, and mechanical responses. By designing appropriate material distributions and structural configurations, the surrounding physical fields are manipulated and accurately reconstructed as if the object or source were located at another position.

This concept enables the apparent location of mechanical, thermal, acoustic, and other physical responses to be shifted without changing the actual location of the object or source, allowing external observers to perceive the physical phenomenon as originating from a different location.

Our laboratory investigates computational design methodologies for realizing location camouflage structures by utilizing topology optimization, advanced optimization algorithms, structural modeling techniques, and constraint-handling strategies. This integrated approach enables the exploration of complex design spaces and the discovery of novel structures that achieve desired spatial control of physical responses while satisfying practical design requirements.

Through the development of topology optimization frameworks for multiphysics applications and multifunctional realizations, we aim to establish new design principles for structures capable of controlling the apparent position of physical phenomena and the spatial distribution of materials.

For more information, see:

Optics Express Vol. 31, Issue 22, pp. 37302–37315 (2023) | Journal of Sound and Vibration Vol. 559, p. 117768 (2023)