FFF produces very straight fiber while maintaining precise control of the diameter, with the ability to vary diameter as fibers grow. Diameter control can be applied to the entire set of fibers, to random subsets, and down to individual fibers. Fiber diameters can range from 15 to 100 microns.
Precision spot coating of fibers is being developed in order to “fill in” thinner sections of fiber with other materials in downstream LCVD reactors. This has application in, for example, the patent-pending nuclear “Fuel-In-Fiber” concept under development for the Department of Energy to contribute to the Accident Tolerant Fuel initiative. It is also key to a patent-pending “micro-embedded” sensor and actuators concept where, for example, temperature or strain sensors, or micro-piezo actuators, can be deposited directly onto fibers intended for use in next-gen composites.