Fluid Bath-Assisted 3D Printing for Biomedical Applications: From Pre- to Postprinting Stages

Abstract

Fluid bath-assisted three-dimensional (3D) printing is an innovative 3D printing strategy that extrudes liquid ink materials into a fluid bath to form various 3D configurations. Since the support bath can provide in situ support, extruded filaments are able to freely construct complex 3D structures. Meanwhile, the supporting function of the fluid bath decreases the dependence of the ink material's cross-linkability, thus broadening the material selections for biomedical applications. Fluid bath-assisted 3D printing can be divided into two subcategories: embedded 3D printing and support bath-enabled 3D printing. This review will introduce and discuss three main manufacturing processes, or stages, for these two strategies. The stages that will be discussed include preprinting, printing, and postprinting. In the preprinting stage, representative fluid bath materials are introduced and the bath material preparation methods are also discussed. In addition, the design criteria of fluid bath materials including biocompatibility, rheological properties, physical/chemical stability, hydrophilicity/hydrophobicity, and other properties are proposed in order to guide the selection and design of future fluid bath materials. For the printing stage, some key technical issues discussed in this review include filament formation mechanisms in a fluid bath, effects of nozzle movement on printed structures, and design strategies for printing paths. In the postprinting stage, some commonly used postprinting processes are introduced. Finally, representative biomedical applications of fluid bath-assisted 3D printing, such as standalone organoids/tissues, biomedical microfluidic devices, and wearable and bionic devices, are summarized and presented.

Three-Dimensional Printing in Stimuli-Responsive Yield-Stress Fluid with an Interactive Dual Microstructure

“…The nanocomposite recovers its interactive dual microstructure faster than Pluronic F127 but slower than nanoclay with a response time of 0.36 s, which indicates that the interactions between spherical micelles and nanoclay platelets may accelerate the formation of the dual microstructure. For support bath-enabled 3D printing, a short response time is always expected , so that the support bath material can rapidly switch from liquid to solid-like states to fill the crevasse behind the nozzle translation and entrap deposited structures in situ .…”

“…As shown in Figure S5a,b, the increase in nozzle diameter and dispensing pressure lead to the increase in filament diameter. In contrast, the increase in path speed, the speed at which the dispensing nozzle moves in the support bath, leads to the decrease in filament diameter, 14,19 as shown in Figure 3a. Also, when the path speed is relatively low, a swelling filament can be formed, which has a diameter larger than the nozzle diameter.…”

“…Among a variety of support bath materials, − yield-stress fluids − are of great significance, which can switch between liquid and solid-like states under different stressed conditions. The unique advantages that yield-stress fluids offer for support bath-enabled 3D printing include the following: (1) self-healing behavior during printing due to repeatable and rapid transition between liquid and solid-like status, thus eliminating the need for additional fillers; (2) solid-like behavior after printing, which provides excellent in situ supports; and (3) physical and/or chemical stability when prepared with suitable solvents, broadening the application scope of support bath-enabled 3D printing for various fabrication scenarios. ,− As a result, yield-stress support bath-enabled 3D printing presents unimaginable potential in different fields, such as tissue engineering, wearable sensors, , soft robotics, , and more.…”

Biomaterials of human source for 3D printing strategies

“…In this technique, the filaments are deposited directly into a secondary shear-thinning structure that allows self-healing upon nozzle passage [123], restricting the bioink flow and allowing for the fabrication of more complex structures, with different cell types and tunable mechanical proprieties upon crosslinking (figure 4(e)) [4,124]. Recent review papers highlight the emerging solutions to embedded printing and the particular challenges in this area [125,126]. One major requirement is that the supporting bath materials do not interact/mix with the ink materials, allowing deposition with high shape and filament fidelity.…”

Laser Additive Manufacturing of Anti-Tetrachiral Endovascular Stents with Negative Poisson’s Ratio and Favorable Cytocompatibility

“…In the work of Roxanne Khalaj et al [ 22 ], coronary stents were manufactured by 3D printing. Weijian Hua et al [ 23 ], showed the 3D printing method to also be a powerful tool for stent manufacturing. Kaitlyn Chua’s work also illustrates how the field of 3D printing and biomedicine can create more innovative devices and products [ 24 ].…”