The concept of 3D printing (3DP) started in mid-1980s with stereolithography where plastic parts could be directly manufactured from curing monomers using ultraviolet light layer-by-layer. This idea of direct printing was very exciting particularly for rapidly prototyping concept models or show-and-tell pieces, but not functional parts. All first generation 3DP processes were focused on polymeric materials and mimicking the size and the shape of a design rather than functional properties. However, from the mid-1990s, 3DP processes started to evolve to manufacturing functional components. Three decades later, 3DP has revolutionized most manufacturing sectors by significantly reducing time to produce elements and minimizing cost related to manufacturing parts with higher complexity.^{Reference Bandyopadhyay and Bose1} The focus is no longer on low-quality plastic parts that are primarily used for ‘touch and feel’ or design validation, but on functional components of metals, ceramics, polymers, and composites that are now routinely manufactured using 3DP and used in almost all sectors from space to toys to biomedical devices. 3DP-related businesses have grown to multi-billion dollar enterprises around the world, and the growth rate continues to rise for most manufacturing sectors worldwide. However, application of 3DP in biomedical devices is still relatively new and only recently have regulatory bodies in different countries begun to approve 3D-printed devices for human use.^{Reference Bose, Ke, Sahasrabudhe and Bandyopadhyay2,Reference Bandyopadhyay, Bose and Das3}

Application of 3DP in biomaterials is being realized in many areas. Polymer-based 3DP technology is the most mature, where manufacturing biopolymer-based parts via 3DP is a growing area of research. These polymers could be bioresorbable for tissue engineering applications or non-resorbable for various functional devices or surgical tools. Following polymers, metals are the next group of materials for which commercial 3DP technologies are mature enough to produce functional devices.

Traditionally, metallic devices are manufactured via casting or forging, followed by final machining or surface modification and finished with sterilization. Use of 3DP can reduce the number of steps needed to manufacture such devices, particularly those where a porous coating can be beneficial, thus reducing the cost of production significantly while increasing the yield. Other salient advantages of 3DP for manufacturing these products lies with smaller footprints for manufacturing operations, on-demand manufacturing as opposed to projection-based manufacturing, and ease of manufacturing patient-matched devices. Using 3DP, complete functional device manufacturing can be done with one or two machines that are not sensitive to design changes. This idea also helps to protect intellectual property at the early stages of product development because even small companies can establish a 3DP facility for design iterations and new product development. Moreover, in the past most biomedical devices were produced based on market prediction or a projection-based systems. If an event changed projections, device manufacturers struggled to meet altered market demand quickly or sat with a large inventory without customers. 3DP technology now allows on-demand manufacturing for shorter lead time to produce parts with different designs and compositions. Finally, there is always demand for patient-matched biomedical devices due to complex fractures, unique anatomy, or concerns related to allergies, just to name a few. Use of 3DP can produce patient-matched devices easily and directly without any design-specific tooling. Such devices can be tailored for specific patient needs without significant addition to manufacturing costs.

3DP of ceramics is still mostly at the research stage due to concerns related to reproducibility and reliability in mechanical properties. However, there is significant interest in 3DP of porous ceramic scaffolds for bone tissue engineering, as these scaffolds can be tailored for their bioresorption ability for different clinical needs.^{Reference Bose, Robertson and Bandyopadhyay4,Reference Bose, Roy and Bandyopadhyay5} Apart from porous scaffolds, 3DP is also being explored to modify surface chemistry via ceramic coatings. 3DP technology for ceramic polymer composites is widely studied for a variety of biomedical device applications. In general, 3DP of ceramics is still in its infancy and expected to grow in the coming years.^{Reference Bose and Bandyopadhyay6}

Since early 2000, 3DP research is growing toward the new field of bioprinting. The concept of bioprinting is simple. Instead of printing acellular materials, live cell-laden materials are printed along with acellular materials with a ultimate goal of organ-tissue engineering. Even in its early stages, bioprinting is being used to create a variety of cell lines for organ tissue engineering using different polymers as a substrate material. Though very exciting, cell viability for larger tissues and their three-dimensional growth remains a challenge.