Embedded 3D printing enables the manufacture of soft, intricate structures. In technique, a nozzle is embedded into viscoelastic support bath and extrudes filaments or droplets. While expands printable materials space to low-viscosity fluids, it also presents new challenges. Filament cross-sections can be tall narrow, have sharp edges, rough surfaces. Filaments rupture contract due capillarity, harming print fidelity. Through digital image analysis in situ videos process images just after...

Abstract Developing mechanically flexible composite materials with high electrical conductivity is currently hindered by the need to use loading of conductive filler, which severely limits flexibility. Here, acoustic focusing used control arrangement particles in photopolymer matrices create composites both tunable and Acoustophoresis patterns filler into highly efficient percolated networks utilize up 97% composite, whereas inefficient stochastic conventional dispersed‐fiber < 5%. These...

Embedded 3D printing, wherein fluid inks are extruded into support baths, has enabled the manufacture of complex, custom structures ranging from cell-laden tissue analogues to soft robots. This method encompasses two techniques: embedded ink writing (EIW), where filaments extruded, and droplet printing (EDP), droplets suspended. Materials for can be Newtonian, but often both bath yield stress fluids, following elastic behavior below shear-thinning, viscous above stress. The effect surface...

Abstract The organ transplantation field requires new approaches for replacing and regenerating tissues due to the lack of adequate transplant methods. Three‐dimensional (3D) extrusion‐based bioprinting is a rapid prototyping approach that can engineer 3D scaffolds tissue regeneration applications. In this process, printed cell‐based constructs, consisting biomaterials, growth factors, cells, are formed by extrusion bioinks from nozzles. However, applies shear stresses often leading cellular...

Embedded 3D printing (EMB3D) is an additive manufacturing technique that enables complex fabrication of soft materials including tissues and silicones. In EMB3D, a nozzle writes continuous filaments into support bath consisting yield stress fluid. Lack fusion defects between can occur because the pushes fluid existing filaments, preventing coalescence. Interfacial tension was previously proposed as tool to drive interfilament fusion. However, interfacial also rupture shrinkage printed...

Acoustic forces can align and consolidate particles in fluids, enabling microstructural control of two-phase materials at time-scales compatible with direct-write printing composites. This paper presents key scaling relationships for acoustically-assisted that describe characteristic assembly alignment during printing. Critical combinations system parameters (including particle nozzle dimensions, acoustic excitation amplitude, viscosity, flow rate) are defined govern focusing the print...

The performance of a micro-acousto-fluidic device designed for microparticle trapping is simulated using three-dimensional (3D) numerical model. It demonstrated by simulations that geometrically asymmetric architecture and actuation can increase the acoustic radiation forces in liquid-filled cavity almost 2 orders magnitude when setting up standing pressure half wave microfluidic chamber. Similarly, experiments with silicon-glass devices show noticeable improvement acoustophoresis 20-μm...

Field-assisted 3D printing has promising applications including cell patterning and functionally graded scaffolds. Direct ink writing can produce 3D-printed multiphase materials with controlled phase distributions established by external fields (such as acoustic fields), which manipulate the position orientation of particles within print nozzle. After filament exits nozzle, its internal microstructure changes because deposition, relaxation, shear during neighboring lines. Using particle...

Extrusion-based bioprinting is a powerful tool for fabricating complex cell-laden constructs. Embedded ink writing (EIW) an extrusion-based printing technique wherein nozzle embedded into support bath writes continuous filaments. Because it allows low-viscosity inks, EIW particularly useful bioprinting. One of the largest challenges in limiting damage that cells experience inside nozzle. Longer shear stress durations and higher magnitudes lead to more damage. Shape fidelity also critical...

Abstract In embedded 3D printing (EMB3D), a nozzle extrudes continuous filaments inside of viscoelastic support bath. Compared to other extrusion processes, EMB3D enables softer structures and print paths that conform better the shape part, allowing for complex such as tissues organs. However, strategies high-quality dimensional accuracy mechanical properties remain undocumented in EMB3D. This work uses computational fluid dynamics simulations OpenFOAM probe underlying physics behind two...

The chiton Acanthopleura granulata uses aragonitic lenses embedded in its shell to focus light onto photoreceptors. Because aragonite is biaxially birefringent, the microstructure of lens greatly impacts optical performance. In addition, lives intertidal, so experience two environments with different refractive indices: air and water. Using EBSD, we find that polycrystalline contains curved grain boundaries. A combination large, twinned grains nanotwins ensure <001> axis consistent across...