Three-Dimensional Printing Fiber Reinforced Hydrogel Composites

Abstract

An additive manufacturing process that combines digital modeling and 3D printing was used to prepare fiber reinforced hydrogels in a single-step process. The composite materials were fabricated by selectively pattering a combination of alginate/acrylamide gel precursor solution and an epoxy based UV-curable adhesive (Emax 904 Gel-SC) with an extrusion printer. UV irradiation was used to cure the two inks into a single composite material. Spatial control of fiber distribution within the digital models allowed for the fabrication of a series of materials with a spectrum of swelling behavior and mechanical properties with physical characteristics ranging from soft and wet to hard and dry. A comparison with the "rule of mixtures" was used to show that the swollen composite materials adhere to standard composite theory. A prototype meniscus cartilage was prepared to illustrate the potential application in bioengineering. ABSTRACTAn additive manufacturing process that combines digital modeling and 3D printing was used to prepare fibre reinforced hydrogels in a single-step process. The composite materials were fabricated by selectively pattering a combination of alginate/acrylamide gel precursor solution and an epoxy based UV-curable adhesive (Emax 904 Gel-SC) with an extrusion printer. UV irradiation was used to cure the two inks into a single composite material. Spatial control of fibre distribution within the digital models allowed for the fabrication of a series of materials with a spectrum of swelling behaviour and mechanical properties with physical characteristics ranging from soft and wet to hard and dry. A comparison with the 'rule of mixtures' was used to show that the swollen composite materials adhere to standard composite theory. A prototype meniscus cartilage was prepared to illustrate the potential application in bioengineering.

3D printing of hydrogel composite systems: Recent advances in technology for tissue engineering

“…Improved mechanical properties Cartilage [95] Anisotropic filler DIW PEGDA, alginate, gelatin Laponite RD, Laponite XLG Improved selfsupporting capacity and young's modulus General [96] 3D plotting N-acryloyl glycinamide Laponite XLG Improved tensile and compression properties and biological properties Bone [97] 3D plotting Alginatemethylcellulose Laponite…”

“…Fiber reinforcements can also improve mechanical properties of hydrogel matrix in which the fiber contents and its distribution inside its matrix determine mechanical properties such as stiffness and strength of composites [92][93][94][95] . In the case of common 3D printing systems, short fiber reinforcements are the most commonly used due to its easy processing procedure at low cost.…”

“…As with 24 wt% continuous fibers, the elastic modulus of composites were twotimes higher, and the maximum strain-to-break ratio was greatly improved compared to that of pure hydrogels [94] . Bakarich et al developed a more advanced technique for fiber-reinforced hydrogel composite system using a onestep process [95] . The previous approach requires at least a two-step fabrication process involving the 3D printing of continuous fiber scaffold structure followed by immersion of the scaffold into a hydrogel precursor solution, and crosslinking.…”

3D/4D Printing Hydrogel Composites: A Pathway to Functional Devices

“…These two inks can be incorporated into the one printing process because they have similar rheological properties, are both cured by UV initiated free radical polymerization reaction and display strong adhesion. [5] Adhesion between materials is important when forming composites for transferring stresses from the matrix onto the reinforcing phase. Adhesion is also important when fabricating multi-component devices as interfaces can act as a point of weakness in the devices structure.…”

“…Tensile testing of the printed materials has shown that composites with higher volume fractions of Emax fibers display greater tensile strength and modulus. [5] The versatility of digital modeling enables these composites to be fabricated directly into complex shapes and useful structures. Figure 1e.…”