Seminar Report on 3D Printing Technologies For 1 Credit Seminar Bhargava Venkatesh 1PI10EE026 November 20, 2013 1 Contents 1 Introduction 3 1.1 The Rise of 3D Printing . 4 1.2 General Principles . 5 1.2.1 Modeling . 5 1.2.2 Printing . 6 1.2.3 Finishing . 7 2 3D Printing Techniques and Materials 8 2.1 3D Printing Techniques . 8 2.2 3D Printing Materials . 10 3 The Future of 3D Printing 13 3.1 3Doodler . 14 3.2 3D Printed Organs . 15 3.3 3D Printed Food . 16 2 Chapter 1 Introduction The purpose of this document is to provide one with an idea about 3D Print- ing trends and technologies. Additive manufacturing or 3D printing is a process of making a three-dimensional solid object of virtually any shape from a digital model. 3D printing is achieved using an additive process, where successive layers of material are laid down in different shapes. 3D printing is also considered distinct from traditional machining techniques, which mostly rely on the removal of material by methods such as cutting or drilling (subtractive processes). 3D printers are used for rapid prototyping which involves sending a Computer Aided Design (CAD) to the printer that is then sliced by a program and printed using a material layer by layer until the full shape is formed. Rapid prototyping does not reproduce models with the same quality and consistency as conventional prototyping methods. This might not be the case in the future as more and more industries and sectors are adopting this technology and more R& D is being performed on various technologies in 3D printing. Also for industries that are design conscious and have time con- straints 3D printing is a better choice. 3D printing uses additive printing technology to print objects in 3D. The printer prints 3D models by adding materials like metals, plastics or poly- mers layer by layer over each other until the required 3 dimensional shape is formed. The printers can print with a precision of 0.1 mm or more, giving the technology to print precise designs with accuracy. 3D printing has already been adopted by industries like aerospace, health- care, automobile, defense and Hollywood. There is also a growing consumer market for home based 3D printers. 3 Figure 1.1: InMoov, a full-size humanoid robot made from 3D-printed parts, designed and built by Gael Langevin of Factices Ateliers in France 1.1 The Rise of 3D Printing The concept of 3D printing re- ally began to be taken seriously in the 1980s. The man most of- ten credited with inventing the lan- guage of 'modern' 3D printer is Charles W. Hull, who used the term stereolithography—defined as a "system for generating three- dimensional objects by creating a cross-sectional pattern of the object to be formed"in a 1984 patent. Manufacturing can be differenti- ated into two types: Additive manufacturing refers to 4 Figure 1.2: Charles W. Hull technologies that create ob- jects through sequential layer- ing. Subtractive manufacturing refers to the technologies that create objects through the removal of material by methods such as cutting and drilling. The 3D printing technology is used for both prototyping and dis- tributed manufacturing with appli- cations in architecture, engineering, construction (AEC), industrial de- sign, automotive, aerospace, mil- itary, engineering, civil engineer- ing, dental and medical industries, biotech (human tissue replacement), fashion, footwear, jewelry, eyewear, Figure 1.3: 3D printed Shoes education, geographic information systems, food, and many other fields. It has been speculated that 3D printing may become a mass mar- ket item because open source 3D printing can easily offset their capital costs by enabling consumers to avoid costs associated with purchasing com- mon household objects. 1.2 General Principles 1.2.1 Modeling Additive manufacturing takes vir- tual blueprints from computer aided design (CAD) or animation model- ing software and "slices" them into digital cross-sections for the machine to successively use as a guideline for printing. Depending on the machine used, material or a binding material is deposited on the build bed or plat- form until material/binder layering is complete and the final 3D model Figure 1.4: 3D Render of the popular internet meme: Grumpy Cat 5 has been "printed." A standard data interface between CAD software and the machines is the STL file format. An STL file approximates the shape of a part or assembly using triangular facets. Smaller facets produce a higher quality surface. PLY is a scanner generated input file format, and VRML (or WRL) files are often used as input for 3D printing technologies that are able to print in full color. There are many Softwares you can use for modelling your 3D models that are 100% free; - Google SketchUp - 3DCrafter - 3Dtin - Anim8or - Art of Illusion - Blender - BRL-CAD - Creo Elements/Direct - DrawPlus Starter Edition - FreeCAD - GLC Player - LeoCAD - K-3D - Tinkercad - Wings 3D 1.2.2 Printing To perform a print, the machine reads the design from an .stl file and lays down successive layers of liquid, powder, paper or sheet material to build the model from a series of cross sections. These layers, which correspond to the virtual cross sections from the CAD model, are joined or automatically fused to create the final shape. The primary advantage of this technique is its ability to create almost any shape or geometric feature. 6 Figure 1.5: An example of a home 3D Printer, the Makerbot Replicator 2 1.2.3 Finishing Though the printer-produced res- olution is sufficient for many ap- plications, printing a slightly over- sized version of the desired ob- ject in standard resolution and then removing material with a higher-resolution subtractive pro- cess can achieve greater preci- sion. Some additive manufacturing techniques are capable of using mul- tiple materials in the course of con- Figure 1.6: The completely printed structing parts. Some are able to Grumpy Cat print in multiple colors and color combinations simultaneously. Some also utilize supports when building. Supports are removable or dissolvable upon completion of the print, and are used to support overhanging features during construction. 7 Chapter 2 3D Printing Techniques and Materials 2.1 3D Printing Techniques Stereolithography(SLA) The first commercially available 3D printer (not called a 3D printer back then) used the stereolithography (SLA) method. This was invented in 1986 by Charles Hull, who also at the time founded the company, 3D Systems. A SLA 3D printer works by concentrating a beam of ultraviolet light focused onto the surface of a vat filled with liquid photocurable resin. The UV laser beam draws out the 3D model one thin layer at a time, hardening that slice of the eventual 3D model as the light hits the resin. Slice after slice is created, with each one bonded to the other, and next thing you know you have a full, extremely high-resolution three dimensional model lifted out of the vat. Unused resin is reusable for the next job. Fused Deposition Modeling (FDM) Also invented in the late 1980s, by Scott Crump, was Fused Deposition Mod- eling (FDM) technology. With patent in hand, he and his wife founded Stratasys in 1988. With FDM, the object is produced by extruding a stream of melted thermoplastic material to form layers. Each layer stacks on top of and fuses with the previous layer as the material hardens almost immediately after leaving the extrusion nozzle. It is one of the less expensive 3D printing methods. Most FDM printers print with ABS plastic (think Lego), as well as PLA (Polylactic acid), a biodegradable polymer, which is produced from organic material. 8 Selective Laser Sintering (SLS) The 1980s were big for inventing 3D printing technologies. Not only were SLA and FDM invented and patented then, but so was Selective Laser Sintering (SLS), by Carl Deckard and colleagues at the University of Texas in Austin. SLS works similarly to SLA, but instead of liquid photopolymer in a vat, youll find powdered materials, such as polystyrene, ceramics, glass, nylon, and metals including steel, titanium, aluminum, and silver. When the laser hits the powder, the powder is fused at that point (sintered). All unsintered powder remains as is, and becomes a support structure for the object. The lack of necessity for any support structure with SLS is an advantage over FDM/FFF and SLA theres none to remove after the model is complete, and no extra waste was created. All unused powder can be used for the next printing. PolyJet photopolymer Objet (acquired by Stratasys) developed this technology: much like a tradi- tional inkjet printer deposits ink, a photopolymer liquid is precisely jetted out and then hardened with a UV light. The layers are stacked successively. The technology allows for various materials and colors to be incorporated into single prints, and at high resolutions. Syringe Extrusion Almost any material that has a creamy viscosity can be used in 3D printers equipped with syringe extruders. This includes materials like clay, cement, silicone, and Play-Doh. Certain foods like chocolate, frosting, and cheese can also be printed with these systems. The syringe may or may not need to be heated, depending on the material; chocolate may need to be kept warm while silicone can be kept at room temperature. Other Methods There are other variants of these technologies. For example there is Selective Laser Melting (SLM), which is like SLS but it fully melts the powder rather than just fusing the powder granules at a lower temperature. This is similar to Electron Beam Melting (EBM) which uses an electron beam instead of a UV laser. And then there is a completely different technology called Lami- nated Object Manufacturing (LOM), where layers of adhesive-coated paper, plastic, or metal laminates are successively glued together and cut to shape with a knife or laser cutter.