In the production of microparticles and nanoparticles, currently available methods utilize two types of approaches. Bottom-up approaches involve processes such as nucleation, chemical reactions, or self-assembly processes, and although the resulting particles vary in shape and size, the particles either cluster together or coalesce into one mass. Top-down approaches use methods such as microfluidics, lithography, and imprint lithography, which yield larger, uniform particles, but are usually limited to a specific type of material and particle size range.
Researchers at UCF and MIT have created an economical, efficient, scalable fabrication method of microparticles and nanoparticles that utilizes fluid instabilities in multi-material fibers. Through this novel technique, spherical particles can be created in a wide range of sizes, from less than a millimeter to the tens of nanometers, using a variety of materials (e.g., glasses, polymers, liquids, and metals). This process uses a top-down, non-lithographic approach that provides precise control of the spherical particles’ composition and structure. This innovation can be applied in many fields such as chemistry, physics, and biology, e.g., the creation of three-dimensional optical and acoustic meta-materials, the enabling of optical-resonance-based sensitive direction of chemical species and pathogens, and the formation of sophisticated controlled-release drug delivery systems.
In this innovative method, a fiber is thermally drawn from a fiber preform material and has a longitudinal fiber length with at least one fiber core containing a longitudinal core axis located parallel to the longitudinal fiber axis, and internally coaxial with at least one outer fiber cladding layer along the fiber length. The fiber is fed through a localized heating source at a temperature above the fiber core’s melting point, yet below the claddings’. Molten droplets are pinched off, one at a time, and are drawn out of the heating area in order for them to solidify. The sequence of particles are located within the fiber and are separated by the fiber cladding material (comprised of silica), resulting in the controllable, scalable production of complex, well-defined, micro-scale and nano-scale structures which are well-ordered, controllably oriented, and immobilized.
- Economical, efficient, scalable process
- Precisely controlled particle formation
- Within biology, chemistry, and physics
- 3D optical and acoustic meta-materials
- Drug delivery
- Optical-resonance-based sensitive direction of chemical species and pathogens
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