  Understanding the growth dynamics of the microbubbles produced by plasmonic
heating can benefit a wide range of applications like microfluidics, catalysis,
micro-patterning and photo-thermal energy conversion. Usually, surface
plasmonic bubbles are generated on plasmonic structures pre-deposited on the
surface subject to laser heating. In this work, we investigate the growth
dynamics of surface microbubbles generated in plasmonic nanoparticle (NP)
suspension. We observe much faster bubble growth rates compared to those in
pure water with surface plasmonic structures. Our analyses show that the
volumetric heating effect around the surface bubble due to the existence of NPs
in the suspension is the key to explain this difference. Such volumetric
heating increases the temperature around the surface bubble more efficiently
compared to surface heating which enhances the expelling of dissolved gas. We
also find that the bubble growth rates can be tuned in a very wide range by
changing the concentration of NPs, besides laser power and dissolved gas
concentration.
