Vibrationally directed assembly of micro- and nanoparticle-polymer composites

Nanomaterial Patterning in 3D Printing

“…This approach to nanomaterial patterning in bulk methods has several attractive attributes. For example, in contrast to an acoustic patterning approach,44,202,203 bulk fluid shear patterning can overcome the misalignment challenges that arise from high particle concentration 204. In contrast to magnetic patterning,29,30,42,77,205 this approach does not require magnetic particles or magnetic fields.…”

“…This transfer depends upon the physical characteristics of the particles such as density, compressibility, and size, as well as the properties of the fluid 283. The pattern of pressure nodes in an acoustic field will drive particle assembly based on the relationship of density and compressibility between the dispersed particles and the fluid medium 203,284. Acoustic patterning is applicable to a broad range of materials.…”

“…Acoustic patterning in 3D printing has been used to create conductive microstructures,44 nanoparticle–polymer composites,203 and to transport domain walls in nanowires 285,286. Literature has also demonstrated the ability of acoustic patterning to pattern nanomaterials in unidirectional features, such as parallel lines,44 and heterogeneous features, such as curves and crisscross patterns 202,203…”

“…Different vibration frequencies achieve different patterns. Reproduced with permission 203. Copyright 2018, Elsevier Ltd.…”

“…This approach excludes the direct use of acoustic tweezers—the particle assembly is driven by the formation of 2D SAW. Shabaniverki et al demonstrated the ability of the vibration‐driven assembly to align particles in an area as large as 3000 mm 2 203. The acoustic radiation force and vibrational fluid flow create localized displacement nodes and anti‐nodes as well as localized shear rates.…”