Design Strategies in Additive Manufacturing: Unveiling the Essence

Post 1: Library-Based Design Categories

Discover the transformative power of Additive Manufacturing (AM), also known as 3D printing. This cutting-edge technique has revolutionized the creation of personalized biomaterials and biomedical devices like implants, prosthetics, and orthotics. By harnessing complex internal structures and customizable properties, AM opens new horizons in patient-specific solutions. Unveil how AM's capabilities extend across diverse biomaterials, including metals, polymers, and ceramics, offering unprecedented advantages for both medical professionals and patients. Delve into this review's insights, exploring design principles that span library-based, bio-inspired, topology optimization, and meta-biomaterial approaches. Explore recent breakthroughs amplifying the quality of 3D-printed biomaterials in biomedical applications, enhancing physical, mechanical, and biological traits. Join us as we showcase 3D-printed biomaterial examples, exemplifying tailored properties and functionalities that redefine possibilities.

Additive manufacturing (AM), commonly referred to as 3D printing, is an advanced manufacturing technique that has revolutionized the creation and customization of specialized or patient-specific biomaterials and biomedical devices, such as implants, prosthetics, and orthotics. This process allows for the fabrication of complex internal microstructures and adjustable properties. Over the recent decades, a variety of design guidelines have been proposed to construct porous lattice structures, particularly in the context of biomedical applications.

The versatility of AM extends to producing a wide array of biomaterials, including metals and alloys, polymers, and ceramics. This capability has ushered in significant advantages for both medical professionals and patients. In this comprehensive review article, we offer an encompassing perspective on the design principles that have emerged and been employed in AM for biomaterials. The strategies devised for biomaterials' AM can be classified into several categories:

Library-Based Design Strategies in Additive Manufacturing: Unveiling the Essence

Within the realm of Additive Manufacturing (AM) or 3D printing, a spectrum of design strategies has emerged, unlocking the potential for intricate and customized structures across diverse applications. This exploration centers on library-based design strategies, encompassing established methodologies and novel innovations that elevate the manufacturing process.

Traditional Framework: CAD and STL Transformation

Traditional design methodologies encompass Computer-Aided Design (CAD), implicit surfaces, and image-based design, forming the foundation of AM capabilities. CAD tools, whether open-source or commercial, serve as the cornerstone for generating conceptual designs. These blueprints are then transformed into the Standard Tessellation Language (STL) format, seamlessly integrating them into the manufacturing workflow. Significantly, STL files can be directly manipulated using software on 3D printing devices, allowing real-time parameter adjustments during the printing process.

Revolutionary Acceleration Techniques

In recent times, ingenious techniques have emerged to expedite manufacturing and address challenges posed by intricate designs. Strategies like the single point exposure scanning approach and vector-based method for selective laser melting (SLM) printing, as well as the voxel-based approach for Polyjet printing, have been introduced. These methods optimize printing time by generating designs with smaller file sizes. This streamlines the handling of complex designs within 3D printing software.

Fig: (a) Library-Based Design Categories: (a) Beam-based unit cells, including cubic, diamond, and truncated cuboctahedron structures. (b) Unveiling Surface-Based Designs: (b) Surface-based unit cells, exemplified by triply periodic minimal surfaces (TPMS). (c) Exploring Disorder and Random Networks: (c) Structures of disordered and random-based networks.

Unit Cells: Cornerstones of Creation

The genesis of lattice structures lies in unit cells, the elemental building blocks of periodic microstructures. Unit cells form ordered patterns, extruded in a 2.5D plane or distributed in 3D space. Two primary unit cell categories emerge: beam-based and sheet-based. Beam-based designs, employed extensively for metallic and non-metallic lattice structures, can be tailored through strut dimension changes, topology shifts, and connectivity variations, influencing attributes like density and pore geometry.

Beam-Based and Surface-Based Ingenuity

Beam-based unit cells are prevalent in crafting lattice structures, showcasing crystalline-like geometries. These designs offer elevated stiffness and mechanical strength, accompanied by sections subjected to bending forces. Surface-based unit cells belong to the implicit surface design realm, driven by mathematical equations defining pore configurations. Triply periodic minimal surfaces (TPMS), a versatile subset of surface-based cells, hold potential in tissue regeneration and ingrowth applications, albeit with fabrication challenges.

Advancements in Disorder and Random Networks

Unit cell arrangement within lattice structures can be disordered or functionally graded, surpassing the capabilities of uniform structures. Disordered designs facilitate diverse property ranges and flexible design, leading to smoother property transitions. Such structures are less susceptible to defects during the AM process, streamlining the amalgamation of varied unit cell types. This innovative design paradigm enhances theoretical mechanical property limits and offers structural integrity and assembly advantages.

The subsequent sections dive into specific unit cell categories, delving deeper into their intricacies and applications within the expansive additive manufacturing landscape.

To be continued.....

Reference

Mirzaali MJ, Moosabeiki V, Rajaai SM, Zhou J, Zadpoor AA. Additive Manufacturing of Biomaterials-Design Principles and Their Implementation. Materials (Basel). 2022 Aug 8;15(15):5457. doi: 10.3390/ma15155457. PMID: 35955393; PMCID: PMC9369548.