Vat Photopolymerization Additive Manufacturing Technology for Bone Tissue Engineering Applications

Abstract

Additive manufacturing has transformed the perspective of producing three dimensions (3D) objects toward achieving high quality in terms of accuracy, resolution, and high mechanical integrity with excellent surface finishing in little time compared to subtractive (traditional) production. Vat photopolymerization (VPP) additive manufacturing is among the most common 3D printing technology used in the medical field, academic research, and industrial production of 3D parts. Four main 3D printing techniques fall under VPP, namely continuous liquid interface production (CLIP), daylight polymer printing (DPP), stereolithography (SLA), and digital light processing (DLP). The last two are the focus of the present article. The high accuracy, precision, the unique ability to produce highly complex porous structural geometries, the low printing cost, and the production time of 3D structures compared to subtractive 3D manufacturing make DLP and SLA suitable for medical applications, specifically in regenerative medicine. This review presents the recent trend of DLP and SLA as used in medical research related to bone tissue engineering highlighting the mechanical and biological properties of the resulting 3D bone structures. In addition, photopolymerization mechanisms, photocurable materials, and the working principles of DLP and SLA are introduced.

Recent Advances in the Additive Manufacturing of Stimuli‐Responsive Soft Polymers

“…[241][242][243] Vat photopolymerization involves the selective curing of a liquid photopolymer resin with a light source to create a solid part. [244] It is further classified into stereolithography (SLA) and digital light processing (DLP). [245][246][247][248][249] In SLA, a laser is used to selectively cure photopolymerizable resins like methacrylamides or acrylates to form a solid object, [250] as illustrated in Figure 3C.…”

Comprehensive Review on Fabricating Bioactive Ceramic Bone Scaffold Using Vat Photopolymerization

“…Most of the photopolymerized ceramic scaffolds are printed by DLP. Compared with the point light source of SLA, DLP technology projects the mask images of the cross-section of the construction object sequentially onto a slurry surface through projection devices without path planning, achieving the curing of a full layer in one exposure (Figure b). − The earliest DLP printers used liquid crystal displays (LCD) as the dynamic mask system, and now, LCDs have been gradually replaced by digital micromirror devices (DMDs). − The DMD contains several hundred thousand microscopic mirrors, which greatly improve printing efficiency while ensuring manufacturing accuracy (printing resolution of 50 μm). , DLP can be divided into top-down and bottom-up approaches according to the direction of light projection. In theory, the latter just needs as much slurry as the part to complete printing .…”

Recent Advancements in Design Optimization of Lattice‐Structured Materials

“…VPP utilizes different types of light sources to cure photocurable resin (or photoresist). [ 63 ] VPP is widely implemented in diverse applications, such as, bone tissue engineering, [ 64 ] dentistry, [ 65 ] and soft sensors and actuators. [ 66 ] Different types of VPP technologies exist, for example, stereolithography (SLA), microstereolithography (μSL), and two‐photon polymerization (TPP).…”