How and What is Made 3D Printing

3D printing also known as additive manufacturing is an old technology that has been referred to as a group of technologies that build physical objects directly from 3D-CAD data file [125].In contrast to subtractive manufacturing technologies (such as milling or machining, cutting, lathing, turning, etc.), in additive manufacturing, physical object is built up by consecutive addition of liquid orThe commonly used materials by 3D printers include polylactic acid, acrylonitrile butadiene styrene and hydrogel composites [126], [127]. While the newly developed material for 3D printing are the liquid crystal elastomers and jammed microgel ink [128], [129]. As already mentioned, 3D printing is at its grown-up stage when compared to other industry 4.0 technologies. However, with the move to industry 4.0, it has been considered to be an essential ingredient.

The technologies behind the development of 3D printing include nanoparticles jetting, laser engineering net shape, wire and arc additive manufacturing, electron beam melting, selective laser sintering/melting, atomic diffusion additive manufacturing, single-pass jetting, fused deposition modeling, direct ink printing and filament extrusion method [75], [130]. With these novel 3D printing technologies, anything can be designed and produced, however, the only limitation will be imposed by the human imaginations [75].3D printing is widely used to produce small batches of customized products that offer construction advantages, such as complex and lightweight designs. Generally, 3D printing has been applied to produce anything ranging from buildings to human organs (e.g.However, its application for printing human organs and other body part is still at its early stage but it is expected to rise tremendously in the industry 4.0 movements.

In addition, the development of 3D printing will majorly tend toward exploring the innovative ways of making living responsive materials (such as shape-memory polymers, aqueous droplet, etc.) and devices (e.g.Cloud computing is a service model where computing services that are available remotely allow users to access applications, data and physical computation resources over a network, on demand or pay-per-useThe application domains of cloud computing technology in education include; e-learning (such as curriculum content management, virtual lab environment, office productivity suite, library management, collaborative learning), communication (e.g.email and notifications) and administration (such as students registration management, Human resources management) [136].In the recent years, cloud computing has been used mainly for some enterprise and analytics applications, but with the move to industry 4.0, the performance of cloud technologies is expectedto improve especially with the security in both network, application and host level [134].

The main companies behind the cloud computing development and deployment are Amazon, Microsoft, Google, and IBM.These cloud providers implement inflexible pricing schemes for cloud users based on the duration [33], [138].Autonomous robots as the name suggest, perform autonomous production method more precisely and also work in the places where human workers are restricted to work.They have the ability to complete the given tasks precisely and intelligently within just the given time and also focus on safety, flexibility, versatility and collaboratively [69], [139].However, in the previous years, robots were designed mainly to tackle complex assignments in the manufacturing industries.Recently, the autonomous robots are also being used in logistics such as warehouses and container terminals [140].The development of autonomous robots has been growing exponentially to meet the need of the industry 4.0 [141], [142].For instance, a European manufacturer of robotic equipment called Kuka, offers autonomous robots that interact with one another.Similarly, one of the industrial-robot manufacturers called ABB has launched a two-armed robot called YuMi that is specifically designed to work alongside humans.The two padded arms and computer vision provide these robots with safe interaction and parts or objects recognition [33].

The major companies behind the autonomous robots innovations and development are Kuka, Rethink Robotics, Bionic robotics, Roberta Gomtec, Honda, ABB, and Fanuc [69].The autonomous robot architecture includes functional and decisional components (e.g.In the era of industry 4.0, the need to develop of these components and exploring new areas of applications of autonomous robots is expected to increase.Virtual reality (VR) and augmented reality (AR) are complementary technologies of industry 4.0. With VR, the users are transported, usually via a headset, into a virtual world. While AR applications present an illusion of layers of graphic information superimposed on some portion of the worker’s field of view [80].In most cases, the two technologies are combined (also known as Mixed reality) to yield gigantic applications by transcending the distance, time and scale and increasing comprehension, teamwork, communications.

Although AR is regarded as regard as developing technology with some of its technical manuals missing [143], it remains emblematic of Industry 4.0, as it blurs the lines between the physical and digital worlds, and, indeed, the public and private sphere [37]. The first application domain of AR and VR was in education since the 1990s to teach subjects like mathematics, geometry, physics, chemistry, anatomy and so on [144]. In the recent years, VR and AR have been applied in virtual training. For instance, a virtual plant-operator training module is being used to train plant personnel to handle emergencies [145].In addition, AR has been applied for maintenance and assembly operations in which it helps workers to know the instructions of repair and other complex tasks in assembly operation. In maintenance, AR has been used to repair and servicing the complex system such as hydraulic breakers [80], [146]. The other application areas of VR and AR include tourism, retail and fashion, business, marketing, storytelling, healthcare, defense, design and development