3D printing of tough hydrogel composites with spatially varying materials properties

Abstract

Biofabrication is the process of transforming materials into systems that reproduce biological structure and function. Previous attempts to create biomimetic systems have often used single materials shaped into limited configurations that do not mimic the heterogeneous structure and properties of many biological tissues. The identification of new bio-inspired materials alongside the development of appropriate fabrication techniques is the key to overcoming the challenge of replicating the functional gradients of these heterogeneous tissues. This paper presents a new extrusion-based gradient printing system that utilizes custom software to control the rates at which two inks are dispensed through a mixing nozzle. The printer was used to fabricate a range of composite materials containing varying blends of a tough alginate/poly(acrylamide) ionic covalent entanglement hydrogel and an acrylated urethane based UV-curable adhesive material. The hard adhesive material acted as particulate reinforcement within the matrix of composites printed with a large hydrogel volume fraction. The composite materials were characterized mechanically and their performance could be modeled with standard composite theory. The platform of a 3D printer allowed these composite materials to be fabricated directly with a smooth and continuous gradient of modulus between the soft hydrogel and harder acrylated urethane material, which may be useful in the development of bio-inspired structures such as artificial tendons.

A Review on Functionally Graded Materials and Structures via Additive Manufacturing: From Multi‐Scale Design to Versatile Functional Properties

“…Fabrication of FGMs with linearly varying properties is ubiquitous for a wide range of material extrusion techniques. Bakarich et al [ 135 ] successfully investigated soft hydrogel and hard UV curable acrylate urethanes to fabricate an artificial tendon‐muscle‐tendon system with spatially linear varying colors. The development of modern equipment and technologies has also made it possible to produce a material with non‐linear gradients.…”

Study on 3D printing of orange concentrate and material characteristics

“…Complex food mixtures like fruit puree or concentrates can be converted into different attractive constructs which are not possible by traditional means of food processing (Antlej & Russo, 2015;Hamilton et al, 2017). Up to date, different gel systems and slurry-type non-food materials have been studied for 3DP (Bakarich et al, 2017;Gong et al, 2014;Shitara et al, 2015). To 3DP a multicomponent system like food/food mixtures, it is necessary to achieve proper flow properties so that the mixtures could be extruded and as well as retain the structure of printed objects after printing.…”

A Review of 3D Food Printing Technology

“…Including, the advantages and disadvantages of those techniques are also established. [1][2][3][4][5][6][7]…”