C. Anandharamakrishnan - 3D Printing of Foods

During the 1990s with the advancements of technology researchers of Stanford and Mellon proposed several other 3D techniques applied for micro‐level casting and spraying of materials. In 1993, MIT filed a patent on inkjet technology that employs liquid‐based ink for the construction of 3D objects commonly used in inkjet printers (Prasad and Smyth 2016). Later this technique was transferred and licensed to Z corporation for the development and marketing of 3D printers. Apart from materials manufacturing at the industrial level, 3D printing allows to produce consumer end products. In 2005, the RepRap project (3D printing open‐source project) was started by Adrian Bowyer at the University of Bath for the development of 3D printers at a low cost that could be affordable to the consumers (Bechtold 2016).

Since the incipient of 3D printing technology, 3D printing has shaped and transformed into different forms. Various technological advancements in the development of these AM processes are summarized in the subsequent sections.

As stated earlier, the 3D printing process was first demonstrated and documented by Kodama of MIT where he developed a method for fabrication of 3D models out of plastics through photo‐hardening of photopolymers cured by ultraviolet (UV) light (Kodama 1981). Later in 1984, three researchers named Mehute, Witte, and Andre filed a patent on the STL process which was unsuccessful with the lack of business potential (Sokolov et al. 2018). After that, the STL technology was commercialized by 3D systems corporations which resulted in a viable manufacturing process for 3D printing. Meanwhile, the other 3D printing FDM technology has become popular as it paved for the production of consumer‐oriented 3D printed products (Sanchez Ramirez et al. 2019). This technology involved extruding hot‐melted plastics through the nozzle die thereby resulting in the deposition of layers to form 3D objects. These printers were quite large as like ‘1970s 5 MB hard disk’ which were then gradually reduced in size with advancements in 3D printing technology.

Around the 1990s, 3D printing received a vast attention due to its advantageous features that drive researchers of different universities to start working on this emerging area. In the 1990s, EOS GmbH developed a ‘stereos’ system, the first commercial industrial 3D printer (Calignano et al. 2019). Then Stratasys filed a patent on FDM technology that leads to the development of domestic 3D printers. In the late 1990s, new technologies were introduced by many aspiring 3D printing companies such as dot‐on‐dot printing techniques that use polymer jet for the fabrication of 3D objects. One such technique is MIT’s inkjet printing that uses polymer solution in a drop‐on‐demand (DoD) manner (Prasad and Smyth 2016). Similarly, the Fraunhofer Institute of Germany introduced selective laser melting (SLM) in 1995 which employs laser light as a curing medium. Meanwhile, the Z corporation worked in collaboration with MIT for the development and production of FDM printers on a commercial scale. Another advancement of printing technology that made its application in the biological field is in regenerative medicine that supports the growth of human organs as the Wake Forest Institute made a successful attempt in the development of tissue scaffolds (Su and Al’Aref 2018). This medieval period remains to be a golden age that promoted various advancements in 3D technologies and 3D printers.

During the start of the twenty‐first century, 3D printing had moved and expanded its wing from the commercial scale and entered into the domestic level. In 2000, the workers of Object Geometries created the first inkjet 3D printer which was then commercialized by Z corporation that paves a way for the development of multi‐colour 3D printer which remains one of the milestones in the evolutionary history of 3D printers (Yang et al. 2018). Later in 2001, the desktop 3D printers were becoming common and in 2002 Wake Forest Institute worked in the development of miniature 3D printed kidney that mimics the functions of the human kidney (Ledford 2015). This leads to the advancements of 3D printing in biomedicine. Around 2005, the open‐source 3D printing project RepRap developed the first 3D printer capable of producing its part named RepRap Darwin (DIY 3D printers). RepRap introduces the word fused filament fabrication (FFF) that replaces the term FDM.

With the innovations of AM, the first 3D printed car was developed by Urbee in 2011, and then in 2013 3D printable gun was released (3DSourced 2021). Gradually the 3D printing moved from polymers to foods as National Aeronautics and Space Administration (NASA) experimented with 3D printing the foods for aeronauts in 2014 (Lipton et al. 2015). Meanwhile, the emergence of flexible new software enhances the mass production of 3D printers in 2017 and until to the present date. Beyond fashion jewellery and aircraft, 3D printing allows for the construction of affordable houses for the developing world. Still, many advancements are happening, and much research is going on in exploring the potential applications of 3D printing in different sectors.

The concept of 3D printing encompasses three key criteria: universal, practical, and efficient. With the development of information and technology, it becomes possible to print foods (one of the essential components for life) in the desired form by uploading a digital file to printers that deliver printed food (Bandyopadhyay and Heer 2018). The main purpose of applying this AM technology in food printing relies on the advantage of designing foods with newer texture, consistency, flavour, and taste with enhanced nutrition ( Figure 1.3). A synergistic combination of material properties, chemical interactions, and binding mechanisms assist in achieving a stable 3D food constructs (Sun et al. 2018a). However, understanding material behaviour is cumbersome that stands to be a challenge in the food printing process since food is a complex substance with a wide variations in its physiochemical characteristics. Globally, several research works are going on in exploring the potential applications of 3D printing in the food sector. Researchers of the Netherlands Organisation for Applied Scientific Research (TNO) have explored the application of food ingredients for 3D printing and converted them to tasty, printed food products because of the health issues due to busy lifestyles and environmental concerns from depletion of resources. Similarly, NASA is exploring and developing 3D printed space foods for astronauts (Sun et al. 2015b).

The idea of customization aids in the delivery of food items as per the requirements and needs. Researchers have customized foods like pizzas and cakes with the idea of incorporating complex shapes and intricate designs using 3D printing technology. Nowadays, the consumer perception towards diet is gradually changing due to changing lifestyle, and different age grouped people require a varying degree of nutrients. Formulating a balanced diet as per individual needs and preferences is the need of the day. This technology allows for personalized meals based on age groups and helps in reduced calorie intake. Thus, the concept of ‘personalized nutrition’ comes into focus which makes possible the delivery of ‘digitalized food’. 3D food printing reduces the multi‐step process into a single step which has the potential to revolutionize the future food industry. The supply chain of 3D food printing allows consumers to have a prime role in the value addition of the end products based on their requirements which is very minimal in the case of a conventional food supply chain ( Figure 1.4) (Jayaprakash et al. 2019).