Hybrid Laser Printing of 3D, Multiscale, Multimaterial Hydrogel Structures

Abstract

Fabrication of multiscale, multimaterial 3D structures at high resolution is difficult using current technologies. This is especially significant when working with mechanically weak hydrogels. Here, a new hybrid laser printing (HLP) technology is reported to print complex, multiscale, multimaterial, 3D hydrogel structures with microscale resolution. This technique utilizes sequential additive and subtractive modes of fabrication, that are typically considered as mutually exclusive due to differences in their material processing conditions. Further, compared to current laser writing systems that enforce stringent processing depth limits, HLP is shown to fabricate structures at any depth inside the material. As a proof‐of‐principle, a Mayan pyramid with embedded cube frame is printed using synthetic polyethylene glycol diacrylate (PEGDA) hydrogel. Printing of ready‐to‐use open‐well chips with embedded microchannels is also demonstrated using PEGDA and gelatin methacrylate (GelMA) hydrogels for potential applications in biomedical sciences. Next, HLP is used in additive–additive modes to print multiscale 3D structures spanning in size from centimeter to micrometers within minutes, which is followed by printing of 3D, multimaterial, multiscale structures using this technology. Overall, this work demonstrates that HLP's fabrication versatility can potentially offer a unique opportunity for a range of applications in optics and photonics, biomedical sciences, microfluidics, etc.

Printability and Shape Fidelity of Bioinks in 3D Bioprinting

“…In DLP ( Figure 9 ), on the other hand, every pixel in each layer is projected in parallel onto the resin, allowing for faster fabrication rates (delivery rate ≈ 20 mm 3 min –1 5 , 248 , 249 ) in lithography-based bioprinting. 167 An advantage of light-based systems over extrusion approaches is the possibility to print structures directly into a volume and therefore even add and remove, via photo-cross-linking or photodegradation, 250 elements from an inner part of construct without altering the bulk of printed structure. While this remains challenging with conventional light projection or laser scanning, like DLP and SLA, in-volume printing, and conversely etching, can be achieved with new single-photon technologies based on tomographic principles, 11 as well as with technologies that rely on multiphoton absorption.…”

Multifunctional Thermoresponsive Microcarriers for High‐Throughput Cell Culture and Enzyme‐Free Cell Harvesting

“…[41] PEGDA is a bioinert material, which has been extensively used to adjust the stiffness of soft hydrogels without altering ligand/receptor density and the bioactivity of the hydrogels. [42][43][44] Further, small and large molecules can be loaded in PEGDA and delivered directly to the cells. The ability to control the pore size of PEGDA hydrogels allows the fine-tuning of the release rate of small and large molecules from the hydrogel.…”

A Bio-Based Resin for a Multi-Scale Optical 3D Printing

“…Also, high interest is shown for the sustainable bio-based products having potential to reduce the adverse environmental impact and be eco-friendly [55][56][57] . In some cases there arises a need to merge pros of both linearly and nonlinearly induced photopolymerization (rapid manufacturing + high spatial resolution) for one material 25,58,59 . However, by this time there is no demonstration of a single resin suitable for the linear and the nonlinear O3DP, maintaining both high throughput and spatial resolution.…”