Dynamic In-Fiber Particle Production With Precise Dimensional Control

A method for producing particles comprising:

• providing a fiber that has been thermally drawn from a fiber preform, the fiber having a longitudinal-axis fiber length and including at least one fiber core having a longitudinal core axis parallel to the longitudinal fiber axis and internally disposed to at least one outer fiber cladding layer of cladding material along the fiber length;
• feeding the fiber through a localized heating site having a heating site temperature, T, that is above a melting temperature of the fiber core, the fiber being fed at a fiber feed speed, υf, that melts a portion of the fiber core at the localized heating site, causing molten droplets to pinch off of fiber core material from the fiber core portion, one droplet at a time, with a time period of molten droplet formation set by the fiber feed speed, υf;
• and
• continually feeding the fiber through the localized heating site to move the molten droplets out of the localized heating site and solidify the molten droplets, producing a longitudinal sequence of solid particles in the fiber, parallel to the longitudinal fiber axis, each particle being separated from other particles in the sequence by the fiber cladding material.