Direct measurement of force exerted during single microbubble generation

Abstract

While there has been progress in the understanding of microbubble mechanics, the force associated with their formation has not previously been measured. Here we directly measure the force exerted during microbubble generation. We illuminate a carbon microfiber immersed in distilled water by using an infrared laser to produce individual bubbles. The fiber is elastically deformable and acts as a force sensor. A force of several nano-Newtons was detected on generation of each bubble. We show that water vaporization is responsible for the primary formation of the bubbles, and their subsequent expansion is caused by the diffusion of dissolved gases.