Influence of 3D-printing conditions on physical properties of hydrogel objects

Abstract

In this paper, we present the relationship between printing parameters of a 3D gel printer "Soft and Wet Intelligent Matter-Easy Realizer (SWIM-ER)" and mechanical properties of the fabricated gel objects by SWIM-ER. The printer is able to fabricate hydrogel objects by scanning of ultra-violet (UV) light irradiation (photopolymerization). Various hydrogels objects were printed with different scanning velocity of UV light. We measured the water content and mesh sizes of gel objects utilizing Scanning Microscopic Light Scattering (SMILS). Furthermore, we also printed the gel objects with multiple scan rates with constant UV light irradiation energy, and measured sizes of gel objects, and performed the compression test. It was observed that the physical properties of printed hydrogel objects are strongly related with 3D printing parameters (scan velocity and number of scans-scan rate) due to difference in crosslinking density of polymer network.

Flexible and Conductive 3D Printable Polyvinylidene Fluoride and Poly(N,N‐dimethylacrylamide) Based Gel Polymer Electrolytes

“…The gel electrolyte becomes softer and more stretchable when the scanning velocity increases because of the failure in constructing dense network as a result of inadequate curing time. [ 26 ] As the UV light power increases, the number of crosslinking point increases resulting in densely crosslinked network formation. The reaction time is long in multiple scanning time and low scanning velocity, as a result the GPEs become hard and brittle.…”

3D Printing of Tough Gels Having Tunable Elastic Modulus from the Same Pre‐Gel Solution

“…The UV radical polymerization reaction is commonly used with SWIM‐ER. It has been shown that the total amount of UV light irradiation is an important factor in 3D gel printing . SWIM‐ER is different from other stereolithographic 3D printers in that the number of scans per layer is possible to be specified.…”

“…SWIM‐ER can form gels with a scan speed ranging from 0.5 to 100 mm s −1 . The elastic modulus of these gels increases as the accumulated light amount increases . The scanning velocity for the bone STL was set at 7.25 mm s −1 and for the flesh STL it was set at 80.0 mm s −1 .…”

“…Physical properties, such as compressive strength and water content, were measured. It was observed that the physical properties of printed hydrogel objects are strongly related to 3D printing parameters, such as scan velocity and number of scans for each layer, due to the difference they make in the crosslinking density of the polymer network . Using these techniques, a soft organ model can be created; however, it is evenly soft.…”

Enormously Low Frictional Surface on Tough Hydrogels Simply Created by Laser-Cutting Process

“…In addition, many kinds of biological tissues are low-friction [29]; hence, this technique is beneficial for constructing the artificial living tissues. Furthermore, the properties of artificial cell membranes have been widely studied to clarify the physicochemical mechanisms governing the behaviors of living cell membranes [30][31][32][33][34][35][36][37], and 3D hydrogel printing techniques [24,38] have been developed in the related fields. By utilizing low-friction processing and such previously obtained knowledges and techniques, artificial living tissues composed of cell models and polymer gel ECMs can be developed.…”