From March 4th to 6th, 2026, the Japanese Symposium on Shock Waves 2025 (JSSW2025) was held at Nagoya University. Mr.Kota Nakashima, a second-year master course student in the Masaaki Tamagawa Laboratory, Department of Biological Functions Engineering, Graduate School of Life Science and Systems Engineering, and his colleagues received the Young Researcher Best Presentation Award for his oral presentation (title: Femtosecond-Laser-Induced Micro Shock Waves and Bubble Dynamics in Water). This award is presented to the principal presenters of a select number of outstanding oral and poster presentations given at the Japanese Symposium on Shock Waves. To be eligible, presenters must be 32 years old or younger as of March 31 of the award year.
Femtosecond lasers can generate microscale shock waves (microshock waves) near the focal point while minimizing thermal damage.Therefore they are expected to be utilized as a source of mechanical stimulation in regenerative medicine. However, many aspects of the generation and propagation behavior of femtosecond laser-induced microshock waves, as well as their relationship with the dynamic behavior of bubbles formed near the focal point, remain unclear. In particular, controlling these phenomena is a major challenge for medical applications involving blood and biological fluids as the surrounding medium.
In this study, microshock waves and laser-induced bubbles generated by focused femtosecond laser irradiation in liquids with different viscosities, including water, were visualized using a high-temporal-resolution shadowgraph method with nanosecond-pulse illumination. For the first time, the results revealed the effects of liquid viscosity on shock-wave propagation characteristics and on bubble dynamics, including their generation, expansion, and collapse behaviors.
Mr.Kota Nakashima
Best Presentation Award
