3D Printing Process

Additive manufacturing has attracted a lot of attention in fabrication of bio medical devices and structures in recent years. 4D printing, a new class of 3D printing where time is considered as a 4th dimension, allows us to build biological structures such as scaffolds, implants, and stents with dynamic performance mimicking the body's natural tissues. In order to properly exploit the capabilities of this fabrication method, understanding and exploiting the shape memory materials is critical. These 'smart' materials are responsive to the external stimuli which eliminates the need for utilizing the sensors, and batteries. These stimuli-triggered 'smart' materials possess a dynamic behavior unlike the static scaffolds based on conventional manufacturing techniques. In this review, recent advances on application of 4D printing for manufacturing of this type of materials and other high-performance biomaterials for medical applications have been discussed.

The aim of this study is to describe the steps needed for producing medical models by 3D printing. Further, the timeline for various 3D printing processes and related process steps and their estimated cost structure will be discussed. Computed tomography images were used as a starting point for the present case and a 3D model of skull and jaw was reconstructed using Osirix software. 3D printing with material extrusion, binder jetting and material jetting processes with pre-and post-processing were explored and a model for the costs and timeline were formed. The results of this study show that, (1) binder jetting clearly is the fastest technique to produce medical models. The total process time varied from 2 h 51 min to 10 h 28 min for the jaw model and from 10 h 24 min to 66 h 13 min for the skull model. Regarding costs, (2) material extrusion is a little more affordable to produce a jaw model followed by binder jetting. To produce a skull model, binder jetting seems more affordable than material extrusion or material jetting. Material jetting is much more expensive than the two other techniques but it is also much more accurate based on the published Le Courrier de la Transplantation-Vol. 18-n 1-2-june 2018 reports. In binder and material jetting adding more parts in the same 3D printing instance will reduce the cost remarkably.

3D Printing also known as additive manufacturing (AM) has been around for some time now, and although it is considered in-development technology, its potential to change our daily lives makes it as one of the most prospect technologies. According to Financial Times it is considered potentially larger than the Internet. AM offers its consumers options to personalize their own products, and a mass customization in industries like Health. Customization cannot be understated, day by day consumers are becoming more demanding, and 3D printing is expected to play a significant role in the future. There is a wide variety of printing processes, some offer better quality but with higher costs, and sometimes with a limited printed material. Overall a low cost, high quality and fast production 3D printing technology is still missing. This paper is meant to be read by all types of readers or for future users and doesn't require a basic knowledge about 3D printing. The main purposes of this paper are to explain what 3D printing is, its past and what the future holds, the different printing technologies and main applications.

3-D printing has potential to revolutionize manufacturing of customized low-cost scientific equipment, and numerous self-designed applications have already been realized and demonstrated. However, the applicability of 3-D printed devices to cleanrooms used for semiconductor processing is not as straightforward, as the controlled environment sets strict requirements for the allowed materials and items. This work investigates the opportunity to utilize 3-D printing in cleanrooms by analyzing three potentially suitable polymers (polylactic acid (PLA), acrylonitrile butadiene styrene (ABS) and polypropylene (PP)) for two applications that do not require particular chemical compatibility: a custom single wafer storage box and a wafer positioner for a metrology system. The designed equipment supplements commercial selection by introducing support for samples with non-standard shape or size and simultaneously reduces the price of often extensively expensive cleanroom equipment. The results show that the single wafer boxes 3-D printed from PLA and ABS generate as little particles as a commercial equivalent, whereas slightly more particles are found from a wafer stored in the self-printed PP box. Nevertheless, the number of particles on all wafers is in the same order of magnitude, indicating that 3-D printed boxes are not significant particle sources. The 3-D wafer positioner seems to cause a negligible particle increase on the manipulated wafer, while abrasion of the mechanical parts generate larger numbers of particles that may disperse in the environment. Regular cleaning of those parts is thus recommended, and applicability in a cleanroom environment will depend on the cleanliness constraints. Elemental analysis reveals that 3-D printed objects contain no other harmful metal impurities than those originating from colorants. Thus, 3-D printing filaments with natural color should be preferred for purposes, where metal contamination could be an issue, including semiconductor processing. Finally, 3-D printing filaments considered in this study are shown to be resistant to isopropanol and deionized water, which is critical for efficient cleaning for use of 3-D printed objects in cleanrooms. The results demonstrate that simple 3-D printed objects, such as wafer boxes or tweezers, are not notable contamination sources, and hence, are equally suitable for use in cleanrooms as the commercial equivalents.

The metal 3-D printing market is currently dominated by high-end applications, which make it inaccessible for small and medium enterprises, fab labs, and individual makers who are interested in the ability to prototype and additively manufacture final products in metal. Recent progress led to low-cost open-source metal 3-D printers using a gas metal arc welding (GMAW)-based print head. This reduced the cost of metal 3-D printers into the range of desktop prosumer polymer 3-D printers. Consequent research established good material properties of metal 3-D printed parts with readily-available weld filler wire, reusable substrates, thermal and stress properties, toolpath planning, bead-width control, mechanical properties, and support for overhangs. These previous works showed that GMAW-based metal 3-D printing has a good adhesion between layers and is not porous inside the printed parts, but they did not proceed far enough to demonstrate applications. In this study, the utility of the GMAW approach to 3-D printing is investigated using a low-cost open-source metal 3-D printer and a converted Computer Numerical Control router machine to make useful parts over a range of applications including: fixing an existing part by adding a 3-D metal feature, creating a product using the substrate as part of the component, 3-D printing in high resolution of useful objects, near net objects, and making an integrated product using a combination of steel and polymer 3-D printing. The results show that GMAW-based 3-D printing is capable of distributed manufacturing of useful products for a wide variety of applications for sustainable development.

The release of the open source 3-D printer known as the RepRap (a self-Replicating Rapid prototyper) resulted in the potential for distributed manufacturing of products for significantly lower costs than conventional manufacturing. This development, coupled with open source-appropriate technology (OSAT), has enabled the opportunity for 3-D printers to be used for sustainable development. In this context, OSAT provides the opportunity to modify and improve the physical designs of their printers and desired digitally-shared objects. However, these 3-D printers require electricity while more than a billion people still lack electricity. To enable the utilization of RepRaps in off-grid communities, solar photovoltaic (PV)-powered mobile systems have been developed, but recent improvements in novel delta-style 3-D printer designs allows for reduced costs and improved performance. This study builds on these innovations to develop and experimentally validate a mobile solar-PV-powered delta 3-D printer system. It is designed to run the RepRap 3-D printer regardless of solar flux. The electrical system design is tested outdoors for operating conditions: (1) PV charging battery and running 3-D printer; (2) printing under low insolation; (3) battery powering the 3-D printer alone; (4) PV charging the battery only; and (5) battery fully charged with PV-powered 3-D printing. The results show the system performed as required under all conditions providing feasibility for adoption in off-grid rural communities. 3-D printers powered by affordable mobile PV solar systems have a great potential to reduce poverty through employment creation, as well as ensuring a constant supply of scarce products for isolated communities.

Through reduced 3-D printer cost, increased usability, and greater material selection, additive manufacturing has transitioned from business manufacturing to the average prosumer. This study serves as a representative model for the potential future of 3-D printing in the average American household by employing a printer operator who was relatively unfamiliar with 3-D printing and the 3-D design files of common items normally purchased by the average consumer. Twenty-six items were printed in thermoplastic and a cost analysis was performed through comparison to comparable, commercially available products at a low and high price range. When compared to the low-cost items, investment in a 3-D printer represented a return of investment of over 100% in five years. The simple payback time for the high-cost comparison was less than 6 months, and produced a 986% return. Thus, fully-assembled commercial open source 3-D printers can be highly profitable investments for American consumers. Finally, as a preliminary gauge of the effect that widespread prosumer use of 3-D printing might have on the economy, savings were calculated based on the items' download rates from open repositories. Results indicate that printing these selected items have already saved prosumers over $4 million by substituting for purchases.

Fused particle fabrication (FPF) (or fused granular fabrication (FGF)) has potential for increasing recycled polymers in 3-D printing. Here, the open source Gigabot X is used to develop a new method to optimize FPF/FGF for recycled materials. Virgin polylactic acid (PLA) pellets and prints were analyzed and were then compared to four recycled polymers including the two most popular printing materials (PLA) and acrylonitrile butadiene styrene (ABS)) as well as the two most common waste plastics (polyethylene terephthalate (PET) and polypropylene (PP)). The size characteristics of the various materials were quantified using digital image processing. Then, power and nozzle velocity matrices were used to optimize the print speed, and a print test was used to maximize the output for a two-temperature stage extruder for a given polymer feedstock. ASTM type 4 tensile tests were used to determine the mechanical properties of each plastic when they were printed with a particle drive extruder system and were compared with filament printing. The results showed that the Gigabot X can print materials 6.5× to 13× faster than conventional printers depending on the material, with no significant reduction in the mechanical properties. It was concluded that the Gigabot X and similar FPF/FGF printers can utilize a wide range of recycled polymer materials with minimal post processing.

En este libro se presenta un listado con actividades propuestas para el aprendizaje del dibujo mediante tecnologías 3D. Estas actividades tienen un carácter creativo porque realiza ejercicios de dibujo de una manera que permiten que el alumno explore diferentes soluciones. Por otro lado el uso de tecnologías de modelado 3D, fabricación digital, y videojuegos estimula la motivación y permite visualizar las soluciones del ejercicio en múltiples formatos (videojuegos, tangibles, digitales..) Las actividades se han dividido en tres grupos diferentes dependiendo de lo que se trabaje en ellas: Capacidad espacial y Vistas Normalizadas, Recursos para la presentación de proyectos de Ingeniería y Creación de maquetas y prototipos mediante la fabricación digital.

The articles in this issue look at how the development and use of free and open source hardware (FOSH or simply “open hardware”) are changing the face of science, engineering, business, and law.

Free and open source software (FOSS) has proven very successful and now dominates the development of software on a global scale. It is available in source code (open source) and can be used, studied, copied, modified, and redistributed either without restriction or with restrictions only to ensure that further recipients have the same open source rights.
Similarly, FOSH provides the “code” for hardware—including the bill of materials, schematics, instructions, computer-aided designs, and other information needed to recreate a physical artifact. Use of FOSH can improve product innovation in a wide range of fields. In this issue authors from a variety of disciplines and work environments discuss how this open model of innovation will drive the future of engineering.
First, Alicia Gibb, founder and executive director of the Open Source Hardware Association (OSHWA) and director of the ATLAS1 Blow Things Up (BTU) Lab at the University of Colorado Boulder, argues that hardware is the next step to open sourcing everything. She touches on intellectual property (IP) issues, cites the benefits of open source hardware, introduces and explains the role of OSHWA, and hints at the future of open hardware.

The open source paradigm is already making deep inroads in the hardware space in 3D printing. With the development of the open source RepRap project (a 3D printer that can print itself) the cost of 3D printers has dropped to a point where nearly anyone can afford one for rapid prototyping and small batch manufacturing.

Ben Malouf and Harris Kenny of Aleph Objects describe their company’s approach to the use of open hardware in every aspect of their business to create the popular Lulzbot 3D printer. Their primary product is open—and consistently wins one of the top spots in Make: Magazine’s annual 3D printer shootout, ahead of proprietary 3D printers from much larger companies with far greater resources. Lulzbot printers, and those of many other manufacturers, are rapidly increasing in sales as the number of free and open source 3D printable designs erupts on the Web, making distributed manufacturing a reality.

In this context, law professor Lucas Osborn at the Campbell University School of Law takes us on a deep dive into how IP law will need to change in this new 3D printing era. After summarizing the basics of IP law and explaining why it was created, he discusses how it could both benefit and hinder 3D printing technology. His arguments will challenge readers independent of their views on patent law. For those with conventional IP leanings, he shows how IP law can hinder innovation. For those born in the Internet age, where sharing is second nature and little thought is given to licenses as long as the code is posted on Github, he offers some important lessons. He ends with a challenge for engineers to make more of an effort in helping form IP law that will benefit innovation.
If these lessons on IP and open hardware replication with 3D printers are turned to experimental research in science and engineering, there is an important opportunity to radically reduce the costs of experimental research while improving it. In the next article I argue that by harnessing a scalable open source method, federal funding is spent just once for the development of scientific equipment and then a return on this investment (ROI) is realized by digital replication of scientific devices for only the costs of materials. With numerous examples I show that the ROI climbs into the thousands of percent while accelerating any research that the open paradigm touches. To harness this opportunity, I propose four straightforward and negative-net-cost policies to support FOSH development and improve access to scientific tools in the United States. The policies will directly save millions in research and STEM education expenditures, while providing researchers and students access to better equipment, which will promote advances in technology and concomitant benefits for the American economy.

Thinking about the future and the changes needed to support this development in STEM education, AnnMarie Thomas and Deb Besser of the St. Thomas School of Engineering consider how engineers and engineering educators can use maker methods to introduce students to engineering and build their technological literacy. They show that the maker movement is closely tied to open hardware and sharing as well as the traits of successful engineers. Makerspaces and fabrication (fab) labs (what Gibb calls hackerspaces) are physical hubs of the maker culture.
Although these trends are clearly important for the United States, this cultural change and open hardware ethos can have dramatic impacts in the developing world. Matthew Rogge, Melissa Menke, and William Hoyle of TechforTrade explain the potential for open source and 3D printing to produce many needed items in low-resource settings, where lack of infrastructure makes local production impractical and high tariffs, unreliable supply chains, and economic instability make importation costly. Saving 90 percent on medical or scientific tools is nice in my lab, for instance, but it literally saves lives in a developing world context.
The issue concludes with an op-ed by Tom Callaway, a senior software engineer at Red Hat, Inc., an open source software company with revenue over $2 billion last year (up 15 percent year over year). What makes this business accomplishment so impressive is that all of the company’s software products are available for free. Although old ways of thinking demand that companies secure a monopoly and certainly not give away “intellectual property” for free, Red Hat’s success comes from offering its customers support, collaboration, control, and a high-quality product. Tom argues that the proven open source software mentality is porting to hardware, opening up incredible opportunities for humanity. He concludes, “open source and open innovation work…. They also empower society and make it possible to push the limits of what is possible. When the barriers to collaboration are lifted, people can accomplish incredible things.”

As all of the articles show, open source tools in the hands of this and future generations of engineers will be incredible indeed.

Scientists have begun using self-replicating rapid prototyper (RepRap) 3-D printers to manufacture open source digital designs of scientific equipment. This approach is refined here to develop a novel instrument capable of performing automated large-area four-point probe measurements. The designs for conversion of a RepRap 3-D printer to a 2-D open source four-point probe (OS4PP) measurement device are detailed for the mechanical and electrical systems. Free and open source software and firmware are developed to operate the tool. The OS4PP was validated against a wide range of discrete resistors and indium tin oxide (ITO) samples of different thicknesses both pre-and post-annealing. The OS4PP was then compared to two commercial proprietary systems. Results of resistors from 10 to 1 MΩ show errors of less than 1% for the OS4PP. The 3-D mapping of sheet resistance of ITO samples successfully demonstrated the automated capability to measure non-uniformities in large-area samples. The results indicate that all measured values are within the same order of magnitude when compared to two proprietary measurement systems. In conclusion, the OS4PP system, which costs less than 70% of manual proprietary systems, is comparable electrically while offering automated 100 micron positional accuracy for measuring sheet resistance over larger areas.

Distributed digital manufacturing of free and open-source scientific hardware (FOSH) used for scientific experiments has been shown to in general reduce the costs of scientific hardware by 90–99%. In part due to these cost savings, the manufacturing of scientific equipment is beginning to move away from a central paradigm of purchasing proprietary equipment to one in which scientists themselves download open-source designs, fabricate components with digital manufacturing technology, and then assemble the equipment themselves. This trend introduces a need for new formal design procedures that designers can follow when targeting this scientific audience. This study provides five steps in the procedure, encompassing six design principles for the development of free and open-source hardware for scientific applications. A case study is provided for an open-source slide dryer that can be easily fabricated for under $20, which is more than 300 times less than some commercial alternatives. The bespoke design is parametric and easily adjusted for many applications. By designing using open-source principles and the proposed procedures, the outcome will be customizable, under control of the researcher, less expensive than commercial options, more maintainable, and will have many applications that benefit the user since the design documentation is open and freely accessible.

Low­cost gas metal arc welding (GMAW)­based 3­D printing has proven effective at additive manufacturing steel and aluminum parts. Early success, however, was based on hand­writing G­code, which is inadequate for the majority of potential users. To enable automated slicing a 3­D model and generating G­code for an acceptable path for GMAW 3­D printing, this paper reports on upgrading of the free and open source CuraEngine. The new slicer, MOSTMetalCura, provides the following novel abilities necessary for GMAW 3­D printing: i) change the perimeter metric from width to track count, ii) avoid movement that overlaps previous weld beads, iii) have infill start immediately after the perimeter finished and in the direction that eliminates translations, iv) add a variable pause between layers to allow for substrate cooling, v) configure GPIO pins to turn on/off the welder, and vi) set optimized wire feed speed and voltage of the welder based on printing speed, layer height, filament diameter, and tool track width. The process for initiating these changes are detailed and the new slicer is used to help improve the function of the printer for ER70S­6 steel. To find the printing function with the smallest bead width based on volume of material, the line width, layer height, and printing speed are varied to provide wire feed speed calculated by MOSTMetalCura, then the settings are used to print 3­D models. The results of 3­D printing three case study objects of increasing geometric complexity using the process methodology improvements presented, which show resolution of 1mm bead widths.