580 California St., Suite 400
San Francisco, CA, 94104
Key research themes
1. How does laser ablation in liquids enable synthesis of ligand-free nanoparticles with tailored properties for catalysis, biomedicine, and sensing?
This research theme explores the fundamental processes and optimization strategies for pulsed laser ablation in liquids (PLAL) as a clean, scalable route for synthesizing nanoparticles without ligands or surfactants. The focus is on understanding how laser and liquid parameters influence nanoparticle size, shape, surface chemistry, and thus application-specific properties, especially for catalysis, biomedical uses, and sensing technologies.
Key finding: This review synthesized that PLAL uniquely generates ligand-free nanoparticles with tunable size distributions and surface properties crucial for catalytic, biomedical, and sensing applications. Notably, the paper stresses... Read more
Key finding: This study demonstrated that laser ablation in liquids can produce pure metal nanoparticles such as Ag, Au, and Cu without chemical additives, and that parameters like laser wavelength, pulse energy, and ablation time... Read more
Key finding: The paper specifically compared different pulse regimes and established that picosecond and femtosecond lasers yield nanoparticles with narrower size distributions and less agglomeration than nanosecond pulses in liquid... Read more
Key finding: This experimental work provided quantified characterization of Ag nanoparticles produced by PLAL in distilled water, reporting narrow size distributions (~12-20 nm), specific localized surface plasmon resonance (LSPR) peaks... Read more
2. What are the mechanistic roles of plasma dynamics and stress confinement in laser ablation in liquid media affecting material ejection and crater formation?
This theme addresses the fundamental physics underpinning laser ablation in liquids, emphasizing how plasma formation, stress wave confinement, cavitation bubble dynamics, and laser-induced plasma-assisted ablation (LIPAA) determine the ablation efficiency, particle ejection, and surface morphology. Understanding these processes is essential to optimize ablation for microfabrication, material processing, and nanoparticle synthesis.
Key finding: Time-resolved experiments and acoustic measurements revealed that under nanosecond laser irradiation with temporal stress confinement, ablation proceeds via expansion and rupture of subsurface cavitation bubbles ejecting... Read more
Key finding: Corroborating previous findings, this work confirms that the radial dimensions, temperature, and density of the laser-induced plasma govern the crater size on glass, and that increased laser fluence causes initial crater... Read more
3. How do laser parameters and ambient conditions, including angle of incidence and liquid environment, influence ablation characteristics and energy transfer dynamics in laser ablation processes?
This theme focuses on how variation in laser beam parameters—pulse duration, fluence, incidence angle—and environmental factors such as ambient gas composition or liquid medium impact laser-material interaction mechanisms, ablation efficiency, particle energies, plasma formation, and angular dependence of ablation pressure, which are fundamental to optimizing laser processing precision and yield.
Key finding: Combining experiments and Monte Carlo simulations, the study demonstrated that hyperthermal particle energies exceeding classical thermal vaporization predictions arise from hydrodynamic plume acceleration and kinetic... Read more
Key finding: Using an analytical planar model adapted for inertial confinement fusion (ICF), the research quantified that mass ablation rate and ablation pressure scale with the 4/3 and 2/3 powers of the cosine of the incidence angle... Read more
Key finding: The comparative analysis across environments (vacuum, air, various liquids) confirmed that confinement effects in liquids enhance laser energy coupling, ablation rates, and nanoparticle uniformity compared to air and vacuum.... Read more
Key finding: Through experimental and numerical studies, the paper showed that water content in ethanol fuels significantly affects laser-induced breakdown plasma characteristics and ignition behavior. Up to 20% water accelerated initial... Read more