The "open source hardware" logo proposed by OSHWA, one of the main defining organizations
The RepRap general-purpose 3D printer with the ability to make copies of most of its own structural parts
Open-source hardware (OSH) consists of physical artifacts of technology designed and offered by the open-design movement. Both free and open-source software (FOSS) and open-source hardware are created by this open-source culture movement and apply a like concept to a variety of components. It is sometimes, thus, referred to as FOSH
(free and open-source hardware). The term usually means that
information about the hardware is easily discerned so that others can
make it – coupling it closely to the maker movement. Hardware design (i.e. mechanical drawings, schematics, bills of material, PCB layout data, HDL source code and integrated circuit layout data), in addition to the software that drives the hardware, are all released under free/libre
terms. The original sharer gains feedback and potentially improvements
on the design from the FOSH community. There is now significant evidence
that such sharing can drive a high return on investment for the scientific community.
The first hardware focused "open source" activities were started around 1997 by Bruce Perens, creator of the Open Source Definition, co-founder of the Open Source Initiative, and a ham radio operator.
He launched the Open Hardware Certification Program, which had the goal
of allowing hardware manufacturers to self-certify their products as
open.
Shortly after the launch of the Open Hardware Certification
Program, David Freeman announced the Open Hardware Specification Project
(OHSpec), another attempt at licensing hardware components whose
interfaces are available publicly and of creating an entirely new
computing platform as an alternative to proprietary computing systems.
In early 1999, Sepehr Kiani, Ryan Vallance and Samir Nayfeh joined
efforts to apply the open-source philosophy to machine design
applications. Together they established the Open Design Foundation (ODF)
as a non-profit corporation and set out to develop an Open Design Definition. But most of these activities faded out after a few years.
By the mid 2000s open-source hardware again became a hub of
activity due to the emergence of several major open-source hardware
projects and companies, such as OpenCores, RepRap (3D printing), Arduino, Adafruit and SparkFun. In 2007, Perens reactivated the openhardware.org website.
Following the Open Graphics Project,
an effort to design, implement, and manufacture a free and open 3D
graphics chip set and reference graphics card, Timothy Miller suggested
the creation of an organization to safeguard the interests of the Open
Graphics Project community. Thus, Patrick McNamara founded the Open Hardware Foundation (OHF) in 2007.
The Tucson Amateur Packet Radio Corporation
(TAPR), founded in 1982 as a non-profit organization of amateur radio
operators with the goals of supporting R&D efforts in the area of
amateur digital communications, created in 2007 the first open hardware
license, the TAPR Open Hardware License. The OSI president Eric S. Raymond expressed some concerns about certain aspects of the OHL and decided to not review the license.
Around 2010 in context of the Freedom Defined project, the Open Hardware Definition was created as collaborative work of many and is accepted as of 2016 by dozens of organizations and companies.
In July 2011, CERN (European Organization for Nuclear Research) released an open-source hardware license, CERN OHL.
Javier Serrano, an engineer at CERN's Beams Department and the founder
of the Open Hardware Repository, explained: "By sharing designs openly,
CERN expects to improve the quality of designs through peer review and
to guarantee their users – including commercial companies – the freedom
to study, modify and manufacture them, leading to better hardware and
less duplication of efforts".
While initially drafted to address CERN-specific concerns, such as
tracing the impact of the organization’s research, in its current form
it can be used by anyone developing open-source hardware.
Following the 2011 Open Hardware Summit, and after heated debates
on licenses and what constitutes open-source hardware, Bruce Perens
abandoned the OSHW Definition and the concerted efforts of those
involved with it.
Openhardware.org, led by Bruce Perens, promotes and identifies
practices that meet all the combined requirements of the Open Source
Hardware Definition, the Open Source Definition, and the Four Freedoms
of the Free Software Foundation Since 2014 openhardware.org is not online and seems to have ceased activity.
The Open Source Hardware Association (OSHWA) at oshwa.org proposes Open source hardware
and acts as hub of open source hardware activity of all genres, while
cooperating with other entities such as TAPR, CERN, and OSI. The OSHWA
was established as an organization in June 2012 in Delaware and filed
for tax exemption status in July 2013. After same debates about trademark interferences with the OSI, in 2012 the OSHWA and the OSI signed a co-existence agreement.
FSF's Replicant project suggested in 2016 an alternative "free hardware" definition, derived from the FSF's four freedoms.
Forms of open-source hardware
The term hardware in open source hardware has been historically used in opposition to the term software
of open source software. That is, to refer to the electronic hardware
on which the software runs (see previous section). However, as more and
more non-electronic hardware products are made open source (for example
Wikihouse, OpenBeam or Hovalin), this term tends to be used back in its
broader sense of "physical product". The field of open source hardware
has been shown to go beyond electronic hardware and to cover a larger
range of product categories such as machine tools, vehicles and medical
equipment. In that sense, hardware
refers to any form of tangible product, may it be electronic hardware,
mechanical hardware, textile or even construction hardware. The Open
Source Hardware (OSHW) Definition 1.0 defines hardware as "tangible
artifacts — machines, devices, or other physical things".
Computers
Due
to a mixture of privacy, security, and environmental concerns, a number
of projects have started that aim to deliver a variety of open-source
computing devices. Examples include the EOMA68 (SBC in a PCMCIA form-factor, intended to be plugged into a laptop or desktop chassis), Novena (bare motherboard with optional laptop chassis), and GnuBee (series of Network Attached Storage devices).
Several retrocomputing hobby groups have created numerous recreations or adaptations of the early home computers of the 1970s and 80s, some of which include improved functionality and more modern components (such as surface-mount ICs and SD card readers). Some hobbyists have also developed add-on cards (such as drive controllers, memory expansion, and sound cards) to improve the functionality of older computers. Miniaturised recreations of vintage computers have also been created.
Electronics
One
of the most popular types of open-source hardware is electronics. There
are numerous companies that provide large varieties of open-source
electronics such as Sparkfun, Adafruit and Seeed. In addition, there are NPOs and companies that provide a specific open-source electronic component such as the Arduino
electronics prototyping platform. There are numerous examples of
speciality open-source electronics such as low-cost voltage and current
GMAW open-source 3-D printer monitor and a robotics-assisted mass spectrometry assay platform. Open-source electronics finds various uses, including automation of chemical procedures.
Mecha(tro)nics
A
large range of products including mechanical components have been
developed so far, from machine tools to vehicles over musical
instruments and medical equipment. Examples of machine-tools are the 3D printers RepRap and Ultimaker as well as the laser cutter Lasersaur. In the category vehicles, we can find bikes like XYZ Space Frame Vehicles and cars like the Tabby OSVehicle. Examples of medical equipment are the echostethoscope echOpen and a wide range of prosthetic hands listed in the review study by Ten Kate et.al. e.g. the OpenBionics’ Prosthetic Hands.
Others
Examples of open-source hardware products can also be found to a lesser extent in construction (Wikihouse) and textile (Kit Zéro Kilomètres).
Licenses
Rather than creating a new license, some open-source hardware projects simply use existing, free and open-source software licenses. These licenses may not accord well with patent law.
Later, several new licenses have been proposed, designed to address issues specific to hardware designs.
In these licenses, many of the fundamental principles expressed in
open-source software (OSS) licenses have been "ported" to their
counterpart hardware projects. New hardware licenses are often explained as the "hardware equivalent" of a well-known OSS license, such as the GPL, LGPL, or BSD license.
Despite superficial similarities to software licenses, most hardware licenses are fundamentally different: by nature, they typically rely more heavily on patent law than on copyright law, as many hardware designs are not copyrightable.
Whereas a copyright license may control the distribution of the source
code or design documents, a patent license may control the use and
manufacturing of the physical device built from the design documents.
This distinction is explicitly mentioned in the preamble of the TAPR Open Hardware License:
"... those who benefit from an OHL
design may not bring lawsuits claiming that design infringes their
patents or other intellectual property."
The OSHW (Open Source Hardware) logo silkscreened on an unpopulated PCB
The
adjective "open-source" not only refers to a specific set of freedoms
applying to a product, but also generally presupposes that the product
is the object or the result of a "process that relies on the
contributions of geographically dispersed developers via the Internet."
In practice however, in both fields of open-source hardware and
open-source software, products may either be the result of a development
process performed by a closed team in a private setting or by a
community in a public environment, the first case being more frequent
than the second which is more challenging.
Establishing a community-based product development process faces
several challenges such as: to find appropriate product data management
tools, document not only the product but also the development process
itself, accepting losing ubiquitous control over the project, ensure
continuity in a context of fickle participation of voluntary project
members, among others.
The Arduino Diecimila, another popular and early open source hardware design.
One of the major differences between developing open-source software
and developing open-source hardware is that hardware results in tangible
outputs, which cost money to prototype and manufacture. As a result,
the phrase "free as in speech, not as in beer", more formally known as Gratis versus Libre,
distinguishes between the idea of zero cost and the freedom to use and
modify information. While open-source hardware faces challenges in
minimizing cost and reducing financial risks for individual project
developers, some community members have proposed models to address these
needs
Given this, there are initiatives to develop sustainable community
funding mechanisms, such as the Open Source Hardware Central Bank.
Extensive discussion has taken place on ways to make open-source hardware as accessible as open-source software.
Providing clear and detailed product documentation is an essential
factor facilitating product replication and collaboration in hardware
development projects. Practical guides have been developed to help
practitioners to do so. Another option is to design products so they are easy to replicate, as exemplified in the concept of open-source appropriate technology.
The process of developing open-source hardware in a community-based setting is alternatively called open design, open source development or open source product development. All these terms are instantiations of the open-source model applicable for the development of any product, may it be software, hardware, cultural, educational, and so on.
A major contributor to the production of open-source hardware
product designs is the scientific community. There has been considerable
work to produce open-source hardware for scientific hardware using a
combination of open-source electronics and 3-D printing.
Other sources of open-source hardware production are vendors of chips
and other electronic components sponsoring contests with the provision
that the participants and winners must share their designs. Circuit Cellar magazine organizes some of these contests.
Open hardware companies are experimenting with different business models. In one example, littleBits
implements open-source business models by making the design files
available for the circuit designs in each littleBits module, in
accordance with the CERN Open Hardware License Version 1.2. In another example, Arduino has registered its name as a trademark.
Others may manufacture their designs but can't put the Arduino name on
them. Thus they can distinguish their products from others by
appellation.
There are many applicable business models for implementing some
open-source hardware even in traditional firms. For example, to
accelerate development and technical innovation the photovoltaic industry has experimented with partnerships, franchises, secondary supplier and completely open-source models.
Recently, many open source hardware projects were funded via crowdfunding on Indiegogo or Kickstarter. Especially popular is Crowd Supply for crowdfunding open hardware projects.
Reception and impact
Richard Stallman, the founder of the free software movement, was in 1999 skeptical on the idea and relevance of Free hardware (his terminology for what is now known as open-source hardware). In a 2015 Wired
article he adapted his point of view slightly; while he still sees no
ethical parallel between free software and free hardware, he
acknowledges the importance. Also, Stallman uses and suggests the term free hardware design over open source hardware, a request which is consistent with his earlier rejection of the term open source software.
The Observatory of Open Source Hardware aims at supporting exchange of best practices between practitioners. It maintains an open access and curated directory of open source hardware products
rated according to their degree of openness. This directory contains
references of more than 200 complex open source hardware products.
3D printing is any of various processes in which material is joined or solidified under computer control to create a three-dimensional object,
with material being added together (such as liquid molecules or powder
grains being fused together), typically layer by layer. In the '90s, 3D
printing techniques were considered suitable only to the production of
functional or aesthetical prototypes and, back then, a more
comprehensive term for 3D printing was rapid prototyping.
Today, the precision, repeatability and material range have increased
to the point that 3D printing is considered as an industrial production
technology, with the name of additive manufacturing. 3D printed objects can have a very complex shape or geometry and are always produced starting from a digital 3D model or a CAD file.
There are many different 3D printing processes, that can be grouped into seven categories:
The most common by number of users is a material extrusion technique called fused deposition modeling (FDM).
This builds a three-dimensional object from a computer-aided design
(CAD) model, usually by successively adding material layer by layer,
unlike the conventional machining process, where material is removed
from a stock item.
The term "3D printing" originally referred to a process that deposits a binder material onto a powder bed with inkjet printer
heads layer by layer. More recently, the term is being used in popular
vernacular to encompass a wider variety of additive manufacturing
techniques. United States and global technical standards use the official term additive manufacturing for this broader sense.
Terminology
The umbrella termadditive manufacturing (AM) gained wide currency in the 2000s, inspired by the theme of material being added together (in any of various ways). In contrast, the term subtractive manufacturing appeared as a retronym for the large family of machining processes with material removal as their common theme. The term 3D printing still referred only to the polymer technologies in most minds, and the term AM
was likelier to be used in metalworking and end use part production
contexts than among polymer, inkjet, or stereolithography enthusiasts.
By the early 2010s, the terms 3D printing and additive manufacturing evolved senses
in which they were alternate umbrella terms for additive technologies,
one being used in popular vernacular by consumer-maker communities and
the media, and the other used more formally by industrial end-use part
producers, machine manufacturers, and global technical standards
organizations. Until recently, the term 3D printing has been associated with machines low-end in price or in capability.
Both terms reflect that the technologies share the theme of material
addition or joining throughout a 3D work envelope under automated
control. Peter Zelinski, the editor-in-chief of Additive Manufacturing magazine, pointed out in 2017 that the terms are still often synonymous in casual usage but that some manufacturing industry experts are increasingly making a sense distinction whereby Additive Manufacturing comprises 3D printing plus other technologies or other aspects of a manufacturing process.
Other terms that have been used as synonyms or hypernyms have included desktop manufacturing, rapid manufacturing (as the logical production-level successor to rapid prototyping), and on-demand manufacturing (which echoes on-demand printing in the 2D sense of printing). That such application of the adjectives rapid and on-demand to the noun manufacturing was novel in the 2000s reveals the prevailing mental model of the long industrial era in which almost all production manufacturing involved long lead times for laborious tooling development. Today, the term subtractive has not replaced the term machining, instead complementing it when a term that covers any removal method is needed. Agile tooling
is the use of modular means to design tooling that is produced by
additive manufacturing or 3D printing methods to enable quick prototyping
and responses to tooling and fixture needs. Agile tooling uses a cost
effective and high quality method to quickly respond to customer and
market needs, and it can be used in hydro-forming, stamping, injection molding and other manufacturing processes.
History
1981 : Early additive manufacturing equipment and materials were developed in the 1980s. In 1981, Hideo Kodama of Nagoya
Municipal Industrial Research Institute invented two additive methods
for fabricating three-dimensional plastic models with photo-hardening thermoset polymer, where the UV exposure area is controlled by a mask pattern or a scanning fiber transmitter.
Three weeks later in 1984, Chuck Hull of 3D Systems Corporation filed his own patent for a stereolithography fabrication system, in which layers are added by curing photopolymers with ultraviolet lightlasers.
Hull defined the process as a "system for generating three-dimensional
objects by creating a cross-sectional pattern of the object to be
formed,". Hull's contribution was the STL (Stereolithography) file format and the digital slicing and infill strategies common to many processes today.
1988: The technology used by most 3D printers to date—especially hobbyist and consumer-oriented models—is fused deposition modeling, a special application of plastic extrusion, developed in 1988 by S. Scott Crump and commercialized by his company Stratasys, which marketed its first FDM machine in 1992.
AM processes for metal sintering or melting (such as selective laser sintering, direct metal laser sintering, and selective laser melting) usually went by their own individual names in the 1980s and 1990s. At the time, all metalworking was done by processes that we now call non-additive (casting, fabrication, stamping, and machining); although plenty of automation was applied to those technologies (such as by robot welding and CNC), the idea of a tool or head moving through a 3D work envelope transforming a mass of raw material
into a desired shape with a toolpath was associated in metalworking
only with processes that removed metal (rather than adding it), such as
CNC milling, CNC EDM, and many others. But the automated techniques that added
metal, which would later be called additive manufacturing, were
beginning to challenge that assumption. By the mid-1990s, new techniques
for material deposition were developed at Stanford and Carnegie Mellon University, including microcasting and sprayed materials. Sacrificial and support materials had also become more common, enabling new object geometries.
1993 : The term 3D printing originally referred to a powder bed process employing standard and custom inkjet print heads, developed at MIT in 1993 and commercialized by Soligen Technologies, Extrude Hone Corporation, and Z Corporation.
The year 1993 also saw the start of a company called Solidscape,
introducing a high-precision polymer jet fabrication system with
soluble support structures, (categorized as a "dot-on-dot" technique).
2009: Fused Deposition Modeling (FDM) printing process patents expired in 2009.
As the various additive processes matured, it became clear that soon metal removal would no longer be the only metalworking
process done through a tool or head moving through a 3D work envelope
transforming a mass of raw material into a desired shape layer by layer.
The 2010s were the first decade in which metal end use parts such as engine brackets and large nuts would be grown (either before or instead of machining) in job production rather than obligately being machined from bar stock
or plate. It is still the case that casting, fabrication, stamping,
and machining are more prevalent than additive manufacturing in
metalworking, but AM is now beginning to make significant inroads, and
with the advantages of design for additive manufacturing, it is clear to engineers that much more is to come.
As technology matured, several authors had begun to speculate that 3D printing could aid in sustainable development in the developing world.
2012: Filabot develops a system for closing the loop with plastic and allows for any FDM or FFF 3D printer to be able to print with a wider range of plastics.
2013:NASA employees Samantha Snabes and Matthew Fiedler create first prototype of large-format, affordable 3D printer, Gigabot, and launch 3D printing company re:3D.
2018: re:3D develops a system that uses plastic pellets that can be made by grinding up waste plastic.
3D models can be generated from 2D pictures taken at a 3D photo booth
3D printable models may be created with a computer-aided design (CAD) package, via a 3D scanner, or by a plain digital camera and photogrammetry software.
3D printed models created with CAD result in reduced errors and can be
corrected before printing, allowing verification in the design of the
object before it is printed.
The manual modeling process of preparing geometric data for 3D computer
graphics is similar to plastic arts such as sculpting. 3D scanning is a
process of collecting digital data on the shape and appearance of a
real object, creating a digital model based on it.
CAD models can be saved in the stereolithography file format (STL),
a de facto CAD file format for additive manufacturing that stores data
based on triangulations of CAD models. STL is not tailored for additive
manufacturing because it generates large file sizes of topology
optimized parts and lattice structures due to the large number of
surfaces involved. A newer CAD file format, the Additive Manufacturing File format (AMF) was introduced in 2011 to solve this problem. It stores information using curved triangulations.
Printing
Before printing a 3D model from an STL file, it must first be examined for errors. Most CAD applications produce errors in output STL files, of the following types:
holes;
faces normals;
self-intersections;
noise shells;
manifold errors.
A step in the STL generation known as "repair" fixes such problems in the original model. Generally STLs that have been produced from a model obtained through 3D scanning often have more of these errors. This is due to how 3D scanning works-as it is often by point to point acquisition, 3D reconstruction will include errors in most cases.
Once completed, the STL file needs to be processed by a piece of
software called a "slicer," which converts the model into a series of
thin layers and produces a G-code file containing instructions tailored to a specific type of 3D printer (FDM printers). This G-code file can then be printed with 3D printing client software
(which loads the G-code, and uses it to instruct the 3D printer during
the 3D printing process).
Printer resolution describes layer thickness and X–Y resolution in dots per inch (dpi) or micrometers (µm). Typical layer thickness is around 100 μm (250 DPI), although some machines can print layers as thin as 16 μm (1,600 DPI). X–Y resolution is comparable to that of laser printers. The particles (3D dots) are around 50 to 100 μm (510 to 250 DPI) in diameter. For that printer resolution, specifying a mesh resolution of 0.01–0.03 mm and a chord length ≤ 0.016 mm generate an optimal STL output file for a given model input file. Specifying higher resolution results in larger files without increase in print quality.
An object being made out of PLA using molten polymer deposition
Construction of a model with contemporary methods can take anywhere
from several hours to several days, depending on the method used and the
size and complexity of the model. Additive systems can typically reduce
this time to a few hours, although it varies widely depending on the
type of machine used and the size and number of models being produced
simultaneously.
Traditional techniques like injection moulding can be less expensive for manufacturing polymer
products in high quantities, but additive manufacturing can be faster,
more flexible and less expensive when producing relatively small
quantities of parts. 3D printers give designers and concept development
teams the ability to produce parts and concept models using a desktop
size printer.
Finishing
Though
the printer-produced resolution is sufficient for many applications,
greater accuracy can be achieved by printing a slightly oversized
version of the desired object in standard resolution and then removing
material using a higher-resolution subtractive process.
The layered structure of all Additive Manufacturing processes
leads inevitably to a strain-stepping effect on part surfaces which are
curved or tilted in respect to the building platform. The effects
strongly depend on the orientation of a part surface inside the building
process.
Some printable polymers such as ABS, allow the surface finish to be smoothed and improved using chemical vapor processes based on acetone or similar solvents.
Some additive manufacturing techniques are capable of using
multiple materials in the course of constructing parts. These techniques
are able to print in multiple colors and color combinations
simultaneously, and would not necessarily require painting.
Some printing techniques require internal supports to be built
for overhanging features during construction. These supports must be
mechanically removed or dissolved upon completion of the print.
All of the commercialized metal 3D printers involve cutting the
metal component off the metal substrate after deposition. A new process
for the GMAW 3D printing allows for substrate surface modifications to remove aluminum or steel.
Processes and printers
Schematic representation of the 3D printing technique known as Fused Filament Fabrication; a filament a) of plastic material is fed through a heated moving head b) that melts and extrudes it depositing it, layer after layer, in the desired shape c). A moving platform e) lowers after each layer is deposited. For this kind of technology additional vertical support structures d) are needed to sustain overhanging parts
A large number of additive processes are available. The main
differences between processes are in the way layers are deposited to
create parts and in the materials that are used. Each method has its own
advantages and drawbacks, which is why some companies offer a choice of
powder and polymer for the material used to build the object.
Others sometimes use standard, off-the-shelf business paper as the
build material to produce a durable prototype. The main considerations
in choosing a machine are generally speed, costs of the 3D printer, of
the printed prototype, choice and cost of the materials, and color
capabilities.
Printers that work directly with metals are generally expensive.
However less expensive printers can be used to make a mold, which is
then used to make metal parts.
ISO/ASTM52900-15 defines seven categories of Additive
Manufacturing (AM) processes within its meaning: binder jetting,
directed energy deposition, material extrusion, material jetting, powder
bed fusion, sheet lamination, and vat photopolymerization.
Some methods melt or soften the material to produce the layers. In Fused filament fabrication, also known as Fused deposition modeling
(FDM), the model or part is produced by extruding small beads or
streams of material which harden immediately to form layers. A filament
of thermoplastic, metal wire, or other material is fed into an extrusion nozzle head (3D printer extruder),
which heats the material and turns the flow on and off. FDM is somewhat
restricted in the variation of shapes that may be fabricated. Another
technique fuses parts of the layer and then moves upward in the working
area, adding another layer of granules and repeating the process until
the piece has built up. This process uses the unfused media to support
overhangs and thin walls in the part being produced, which reduces the
need for temporary auxiliary supports for the piece.
Recently, FFF/FDM has expanded to 3-D print directly from pellets to
avoid the conversion to filament. This process is called fused particle
fabrication (FPF) (or fused granular fabrication (FGF) and has the
potential to use more recycled materials.
Laser sintering techniques include selective laser sintering, with both metals and polymers, and direct metal laser sintering. Selective laser melting
does not use sintering for the fusion of powder granules but will
completely melt the powder using a high-energy laser to create fully
dense materials in a layer-wise method that has mechanical properties
similar to those of conventional manufactured metals. Electron beam melting is a similar type of additive manufacturing technology for metal parts (e.g. titanium alloys). EBM manufactures parts by melting metal powder layer by layer with an electron beam in a high vacuum. Another method consists of an inkjet 3D printing system, which creates the model one layer at a time by spreading a layer of powder (plaster, or resins) and printing a binder in the cross-section of the part using an inkjet-like process. With laminated object manufacturing, thin layers are cut to shape and joined together.
Schematic representation of Stereolithography; a light-emitting device a) (laser or DLP) selectively illuminate the transparent bottom c) of a tank b) filled with a liquid photo-polymerizing resin; the solidified resin d) is progressively dragged up by a lifting platform e)
Other methods cure liquid materials using different sophisticated technologies, such as stereolithography. Photopolymerization is primarily used in stereolithography to produce a solid part from a liquid. Inkjet printer systems like the Objet PolyJet system spray photopolymer
materials onto a build tray in ultra-thin layers (between 16 and 30 µm)
until the part is completed. Each photopolymer layer is cured
with UV light after it is jetted, producing fully cured models that can
be handled and used immediately, without post-curing. Ultra-small
features can be made with the 3D micro-fabrication technique used in multiphoton
photopolymerisation. Due to the nonlinear nature of photo excitation,
the gel is cured to a solid only in the places where the laser was
focused while the remaining gel is then washed away. Feature sizes of
under 100 nm are easily produced, as well as complex structures with
moving and interlocked parts. Yet another approach uses a synthetic resin that is solidified using LEDs.
In Mask-image-projection-based stereolithography, a 3D digital
model is sliced by a set of horizontal planes. Each slice is converted
into a two-dimensional mask image. The mask image is then projected onto
a photocurable liquid resin surface and light is projected onto the
resin to cure it in the shape of the layer. Continuous liquid interface production begins with a pool of liquid photopolymerresin. Part of the pool bottom is transparent to ultraviolet light
(the "window"), which causes the resin to solidify. The object rises
slowly enough to allow resin to flow under and maintain contact with the
bottom of the object.
In powder-fed directed-energy deposition, a high-power laser is used
to melt metal powder supplied to the focus of the laser beam. The powder
fed directed energy process is similar to Selective Laser Sintering,
but the metal powder is applied only where material is being added to
the part at that moment.
As of December 2017, additive manufacturing systems were on the
market that ranged from $99 to $500,000 in price and were employed in
industries including aerospace, architecture, automotive, defense, and
medical replacements, among many others. For example, General Electric uses the high-end model to build parts for turbines.
Many of these systems are used for rapid prototyping, before mass
production methods are employed. Higher education has proven to be a
major buyer of desktop and professional 3D printers which industry
experts generally view as a positive indicator. Libraries around the world have also become locations to house smaller 3D printers for educational and community access.
Several projects and companies are making efforts to develop affordable
3D printers for home desktop use. Much of this work has been driven by
and targeted at DIY/Maker/enthusiast/early adopter communities, with additional ties to the academic and hacker communities.
Applications
The Audi RSQ was made with rapid prototyping industrial KUKA robots.
A 3D selfie in 1:20 scale printed using gypsum-based printing
A 3D printed jet engine turbine model
3D printed enamelled pottery.
3D printed sculpture of an Egyptian Pharaoh shown at Threeding
In the current scenario, 3D printing or Additive Manufacturing has
been used in manufacturing, medical, industry and sociocultural sectors
which facilitate 3D printing or Additive Manufacturing to become
successful commercial technology. The earliest application of additive manufacturing was on the toolroom end of the manufacturing spectrum. For example, rapid prototyping was one of the earliest additive variants, and its mission was to reduce the lead time
and cost of developing prototypes of new parts and devices, which was
earlier only done with subtractive toolroom methods such as CNC milling,
turning, and precision grinding. In the 2010s, additive manufacturing entered production to a much greater extent.
Additive manufacturing of food is being developed by squeezing
out food, layer by layer, into three-dimensional objects. A large
variety of foods are appropriate candidates, such as chocolate and
candy, and flat foods such as crackers, pasta, and pizza.
3D printing has entered the world of clothing, with fashion designers experimenting with 3D-printed bikinis, shoes, and dresses.
In commercial production Nike is using 3D printing to prototype and
manufacture the 2012 Vapor Laser Talon football shoe for players of
American football, and New Balance is 3D manufacturing custom-fit shoes
for athletes.
3D printing has come to the point where companies are printing
consumer grade eyewear with on-demand custom fit and styling (although
they cannot print the lenses). On-demand customization of glasses is
possible with rapid prototyping.
Vanessa Friedman, fashion director and chief fashion critic at
The New York Times, says 3D printing will have a significant value for
fashion companies down the road, especially if it transforms into a
print-it-yourself tool for shoppers. "There's real sense that this is
not going to happen anytime soon," she says, "but it will happen, and it
will create dramatic change in how we think both about intellectual
property and how things are in the supply chain." She adds: "Certainly
some of the fabrications that brands can use will be dramatically
changed by technology."
In cars, trucks, and aircraft, Additive Manufacturing is beginning to transform both (1) unibody and fuselage design and production and (2) powertrain design and production. For example:
In early 2014, Swedish supercar manufacturer Koenigsegg announced the One:1, a supercar that utilizes many components that were 3D printed. Urbee
is the name of the first car in the world car mounted using the
technology 3D printing (its bodywork and car windows were "printed").
In 2014, Local Motors debuted Strati, a functioning vehicle that was entirely 3D Printed using ABS plastic and carbon fiber, except the powertrain. In May 2015 Airbus announced that its new Airbus A350 XWB included over 1000 components manufactured by 3D printing.
AM's impact on firearms involves two dimensions: new manufacturing
methods for established companies, and new possibilities for the making
of do-it-yourself firearms. In 2012, the US-based group Defense Distributed disclosed plans to design a working plastic 3D printed firearm "that could be downloaded and reproduced by anybody with a 3D printer."
After Defense Distributed released their plans, questions were raised
regarding the effects that 3D printing and widespread consumer-level CNC machining may have on gun control effectiveness.
Surgical uses of 3D printing-centric therapies have a history
beginning in the mid-1990s with anatomical modeling for bony
reconstructive surgery planning. Patient-matched implants were a natural
extension of this work, leading to truly personalized implants that fit
one unique individual.
Virtual planning of surgery and guidance using 3D printed, personalized
instruments have been applied to many areas of surgery including total
joint replacement and craniomaxillofacial reconstruction with great
success. One example of this is the bioresorbable trachial splint to treat newborns with tracheobronchomalacia developed at the University of Michigan. The use of additive
manufacturing for serialized production of orthopedic implants (metals)
is also increasing due to the ability to efficiently create porous
surface structures that facilitate osseointegration. The hearing aid and
dental industries are expected to be the biggest area of future
development using the custom 3D printing technology.
In March 2014, surgeons in Swansea used 3D printed parts to
rebuild the face of a motorcyclist who had been seriously injured in a
road accident. In May 2018, 3D printing has been used for the kidney transplant to save a three-year-old boy. As of 2012, 3D bio-printing technology has been studied by biotechnology firms and academia for possible use in tissue engineering applications in which organs and body parts are built using inkjet printing
techniques. In this process, layers of living cells are deposited onto a
gel medium or sugar matrix and slowly built up to form
three-dimensional structures including vascular systems. Recently, a heart-on-chip has been created which matches properties of cells.
In 2018, 3D printing technology was used for the first time to
create a matrix for cell immobilization in fermentation. Propionic acid
production by Propionibacterium acidipropionici immobilized on
3D-printed nylon beads was chosen as a model study. It was shown that
those 3D-printed beads were capable to promote high density cell
attachment and propionic acid production, which could be adapted to
other fermentation bioprocesses.
In 2005, academic journals had begun to report on the possible artistic applications of 3D printing technology.
As of 2017, domestic 3D printing was reaching a consumer audience
beyond hobbyists and enthusiasts. Off the shelf machines were
increasingly capable of producing practical household applications, for
example, ornamental objects. Some practical examples include a working
clock and gears printed for home woodworking machines among other purposes. Web sites associated with home 3D printing tended to include backscratchers, coat hooks, door knobs, etc.
3D printing, and open source 3D printers in particular, are the latest technology making inroads into the classroom. Some authors have claimed that 3D printers offer an unprecedented "revolution" in STEM education. The evidence for such claims comes from both the low-cost ability for rapid prototyping in the classroom by students, but also the fabrication of low-cost high-quality scientific equipment from open hardware designs forming open-source labs. Future applications for 3D printing might include creating open-source scientific equipment.
In the last several years 3D printing has been intensively used by in the cultural heritage field for preservation, restoration and dissemination purposes. Many Europeans and North American Museums have purchased 3D printers and actively recreate missing pieces of their relics. The Metropolitan Museum of Art and the British Museum have started using their 3D printers to create museum souvenirs that are available in the museum shops.
Other museums, like the National Museum of Military History and Varna
Historical Museum, have gone further and sell through the online
platform Threeding digital models of their artifacts, created using Artec 3D scanners, in 3D printing friendly file format, which everyone can 3D print at home.
3D printed soft actuators
is a growing application of 3D printing technology which has found its
place in the 3D printing applications. These soft actuators are being
developed to deal with soft structures and organs especially in
biomedical sectors and where the interaction between human and robot is
inevitable. The majority of the existing soft actuators are fabricated
by conventional methods that require manual fabrication of devices, post
processing/assembly, and lengthy iterations until maturity in the
fabrication is achieved. To avoid the tedious and time-consuming aspects
of the current fabrication processes, researchers are exploring an
appropriate manufacturing approach for effective fabrication of soft
actuators. Thus, 3D printed soft actuators are introduced to
revolutionise the design and fabrication of soft actuators with custom
geometrical, functional, and control properties in a faster and
inexpensive approach. They also enable incorporation of all actuator
components into a single structure eliminating the need to use external joints, adhesives, and fasteners.
Legal aspects
Intellectual property
3D printing has existed for decades within certain manufacturing industries where many legal regimes, including patents, industrial design rights, copyright, and trademark may apply. However, there is not much jurisprudence
to say how these laws will apply if 3D printers become mainstream and
individuals or hobbyist communities begin manufacturing items for
personal use, for non-profit distribution, or for sale.
Any of the mentioned legal regimes may prohibit the distribution
of the designs used in 3D printing, or the distribution or sale of the
printed item. To be allowed to do these things, where an active
intellectual property was involved, a person would have to contact the
owner and ask for a licence, which may come with conditions and a price.
However, many patent, design and copyright laws contain a standard
limitation or exception for 'private', 'non-commercial' use of
inventions, designs or works of art protected under intellectual
property (IP). That standard limitation or exception may leave such
private, non-commercial uses outside the scope of IP rights.
Patents cover inventions including processes, machines,
manufactures, and compositions of matter and have a finite duration
which varies between countries, but generally 20 years from the date of
application. Therefore, if a type of wheel is patented, printing, using,
or selling such a wheel could be an infringement of the patent.
Copyright covers an expression in a tangible, fixed medium and often lasts for the life of the author plus 70 years thereafter.
If someone makes a statue, they may have copyright on the look of that
statue, so if someone sees that statue, they cannot then distribute
designs to print an identical or similar statue.
When a feature has both artistic (copyrightable) and functional
(patentable) merits, when the question has appeared in US court, the
courts have often held the feature is not copyrightable unless it can be
separated from the functional aspects of the item.
In other countries the law and the courts may apply a different
approach allowing, for example, the design of a useful device to be
registered (as a whole) as an industrial design on the understanding
that, in case of unauthorized copying, only the non-functional features
may be claimed under design law whereas any technical features could
only be claimed if covered by a valid patent.
Gun legislation and administration
The US Department of Homeland Security and the Joint Regional Intelligence Center
released a memo stating that "significant advances in three-dimensional
(3D) printing capabilities, availability of free digital 3D printable
files for firearms components, and difficulty regulating file sharing
may present public safety risks from unqualified gun seekers who obtain
or manufacture 3D printed guns" and that "proposed legislation to ban 3D
printing of weapons may deter, but cannot completely prevent, their
production. Even if the practice is prohibited by new legislation,
online distribution of these 3D printable files will be as difficult to
control as any other illegally traded music, movie or software files."
Attempting to restrict the distribution of gun plans via the
Internet has been likened to the futility of preventing the widespread
distribution of DeCSS, which enabled DVD ripping. After the US government had Defense Distributed take down the plans, they were still widely available via the Pirate Bay and other file sharing sites. Downloads of the plans from the UK, Germany, Spain, and Brazil were heavy. Some US legislators have proposed regulations on 3D printers to prevent them from being used for printing guns.
3D printing advocates have suggested that such regulations would be
futile, could cripple the 3D printing industry, and could infringe on
free speech rights, with early pioneer of 3D printing Professor Hod Lipson suggesting that gunpowder could be controlled instead.
Internationally, where gun controls are generally stricter than
in the United States, some commentators have said the impact may be more
strongly felt since alternative firearms are not as easily obtainable. Officials in the United Kingdom have noted that producing a 3D printed gun would be illegal under their gun control laws. Europol
stated that criminals have access to other sources of weapons but noted
that as technology improves, the risks of an effect would increase.
Aerospace regulation
In
the United States, the FAA has anticipated a desire to use additive
manufacturing techniques and has been considering how best to regulate
this process.
The FAA has jurisdiction over such fabrication because all aircraft
parts must be made under FAA production approval or under other FAA
regulatory categories. In December 2016, the FAA approved the production of a 3D printed fuel nozzle for the GE LEAP engine.
Aviation attorney Jason Dickstein has suggested that additive
manufacturing is merely a production method, and should be regulated
like any other production method.
He has suggested that the FAA's focus should be on guidance to explain
compliance, rather than on changing the existing rules, and that
existing regulations and guidance permit a company "to develop a robust
quality system that adequately reflects regulatory needs for quality
assurance."
Health and safety
Research on the health and safety concerns of 3D printing is new and
in development due to the recent proliferation of 3D printing devices.
In 2017 the European Agency for Safety and Health at Work
has published a discussion paper on the processes and materials
involved in 3D printing, potential implications of this technology for
occupational safety and health and avenues for controlling potential
hazards.
Most concerns involve gas and material exposures, in particular
nanomaterials, material handling, static electricity, moving parts and
pressures.
The toxicity from emissions varies by source material due to differences in size, chemical properties, and quantity of emitted particles. Excessive exposure to VOCs
can lead to irritation of the eyes, nose, and throat, headache, loss of
coordination, and nausea and some of the chemical emissions of fused
filament printers have also been linked to asthma. Based on animal studies, carbon nanotubes and carbon nanofibers sometimes used in fused filament printing can cause pulmonary effects including inflammation, granulomas, and pulmonary fibrosis when at the nanoparticle size.
As of March 2018, the US Government has set 3D printer emission
standards for only a limited number of compounds. Furthermore, the few
established standards address factory conditions, not home or other
environments in which the printers are likely to be used.
Carbon nanoparticle emissions and processes using powder metals are highly combustible and raise the risk of dust explosions. At least one case of severe injury was noted from an explosion involved in metal powders used for fused filament printing. Other general health and safety concerns include the hot surface of UV lamps and print head blocks, high voltage, ultraviolet radiation from UV lamps, and potential for mechanical injury from moving parts.
The problems noted in the NIOSH report were reduced by using manufacturer-supplied covers and full enclosures, using proper ventilation, keeping workers away from the printer, using respirators,
turning off the printer if it jammed, and using lower emission printers
and filaments. At least one case of severe injury was noted from an
explosion involved in metal powders used for fused filament. Personal protective equipment
has been found to be the least desirable control method with a
recommendation that it only be used to add further protection in
combination with approved emissions protection.
Hazards to health and safety also exist from post-processing
activities done to finish parts after they have been printed. These
post-processing activities can include chemical baths, sanding,
polishing, or vapor exposure to refine surface finish, as well as
general subtractive manufacturing techniques such as drilling, milling, or turning to modify the printed geometry.
Any technique that removes material from the printed part has the
potential to generate particles that can be inhaled or cause eye injury
if proper personal protective equipment is not used, such as respirators
or safety glasses. Caustic baths are often used to dissolve support
material used by some 3D printers that allows them to print more complex
shapes. These baths require personal protective equipment to prevent
injury to exposed skin.
Since 3-D imaging creates items by fusing materials together,
there runs the risk of layer separation in some devices made using 3-D
Imaging. For example, in January 2013, the US medical device company,
DePuy, recalled their knee and hip replacement systems. The devices were
made from layers of metal, and shavings had come loose – potentially
harming the patient.
Impact
Additive manufacturing, starting with today's infancy period, requires manufacturing firms to be flexible, ever-improving users of all available technologies to remain competitive. Advocates of additive manufacturing also predict that this arc of technological development will counter globalization,
as end users will do much of their own manufacturing rather than engage
in trade to buy products from other people and corporations.
The real integration of the newer additive technologies into commercial
production, however, is more a matter of complementing traditional
subtractive methods rather than displacing them entirely.
Street sign in Windhoek, Namibia, advertising 3D printing, July 2018.
Since the 1950s, a number of writers and social commentators have
speculated in some depth about the social and cultural changes that
might result from the advent of commercially affordable additive
manufacturing technology.
Among the more notable ideas to have emerged from these inquiries has
been the suggestion that, as more and more 3D printers start to enter
people's homes, the conventional relationship between the home and the
workplace might get further eroded.
Likewise, it has also been suggested that, as it becomes easier for
businesses to transmit designs for new objects around the globe, so the
need for high-speed freight services might also become less.
Finally, given the ease with which certain objects can now be
replicated, it remains to be seen whether changes will be made to
current copyright legislation so as to protect intellectual property
rights with the new technology widely available.
As 3D printers became more accessible to consumers, online social platforms have developed to support the community.
This includes websites that allow users to access information such as
how to build a 3D printer, as well as social forums that discuss how to
improve 3D print quality and discuss 3D printing news, as well as social
media websites that are dedicated to share 3D models.
RepRap is a wiki based website that was created to hold all information
on 3d printing, and has developed into a community that aims to bring
3D printing to everyone. Furthermore, there are other sites such as Pinshape, Thingiverse and MyMiniFactory,
which were created initially to allow users to post 3D files for anyone
to print, allowing for decreased transaction cost of sharing 3D files.
These websites have allowed greater social interaction between users,
creating communities dedicated to 3D printing.
Some call attention to the conjunction of Commons-based peer production with 3D printing and other low-cost manufacturing techniques.
The self-reinforced fantasy of a system of eternal growth can be
overcome with the development of economies of scope, and here, society
can play an important role contributing to the raising of the whole
productive structure to a higher plateau of more sustainable and
customized productivity.
Further, it is true that many issues, problems, and threats arise due
to the democratization of the means of production, and especially
regarding the physical ones.
For instance, the recyclability of advanced nanomaterials is still
questioned; weapons manufacturing could become easier; not to mention
the implications for counterfeiting and on IP. It might be maintained that in contrast to the industrial paradigm whose competitive dynamics were about economies of scale, Commons-based peer production
3D printing could develop economies of scope. While the advantages of
scale rest on cheap global transportation, the economies of scope share
infrastructure costs (intangible and tangible productive resources),
taking advantage of the capabilities of the fabrication tools. And following Neil Gershenfeld
in that "some of the least developed parts of the world need some of
the most advanced technologies," Commons-based peer production and 3D
printing may offer the necessary tools for thinking globally but acting
locally in response to certain needs.
Larry Summers
wrote about the "devastating consequences" of 3D printing and other
technologies (robots, artificial intelligence, etc.) for those who
perform routine tasks. In his view, "already there are more American men
on disability insurance than doing production work in manufacturing.
And the trends are all in the wrong direction, particularly for the less
skilled, as the capacity of capital embodying artificial intelligence
to replace white-collar as well as blue-collar work will increase
rapidly in the years ahead." Summers recommends more vigorous
cooperative efforts to address the "myriad devices" (e.g., tax havens,
bank secrecy, money laundering, and regulatory arbitrage) enabling the
holders of great wealth to "avoid paying" income and estate taxes, and
to make it more difficult to accumulate great fortunes without requiring
"great social contributions" in return, including: more vigorous
enforcement of anti-monopoly laws, reductions in "excessive" protection
for intellectual property, greater encouragement of profit-sharing
schemes that may benefit workers and give them a stake in wealth
accumulation, strengthening of collective bargaining arrangements,
improvements in corporate governance, strengthening of financial
regulation to eliminate subsidies to financial activity, easing of
land-use restrictions that may cause the real estate of the rich to keep
rising in value, better training for young people and retraining for
displaced workers, and increased public and private investment in
infrastructure development—e.g., in energy production and
transportation.
Michael Spence
wrote that "Now comes a … powerful, wave of digital technology that is
replacing labor in increasingly complex tasks. This process of labor
substitution and disintermediation
has been underway for some time in service sectors—think of ATMs,
online banking, enterprise resource planning, customer relationship
management, mobile payment systems, and much more. This revolution is
spreading to the production of goods, where robots and 3D printing are
displacing labor." In his view, the vast majority of the cost of digital
technologies comes at the start, in the design of hardware (e.g. 3D
printers) and, more important, in creating the software that enables
machines to carry out various tasks. "Once this is achieved, the
marginal cost of the hardware is relatively low (and declines as scale
rises), and the marginal cost of replicating the software is essentially
zero. With a huge potential global market to amortize the upfront fixed
costs of design and testing, the incentives to invest [in digital
technologies] are compelling."
Spence believes that, unlike prior digital technologies, which
drove firms to deploy underutilized pools of valuable labor around the
world, the motivating force in the current wave of digital technologies
"is cost reduction via the replacement of labor." For example, as the
cost of 3D printing technology declines, it is "easy to imagine" that
production may become "extremely" local and customized. Moreover,
production may occur in response to actual demand, not anticipated or
forecast demand. Spence believes that labor, no matter how inexpensive,
will become a less important asset for growth and employment expansion,
with labor-intensive, process-oriented manufacturing becoming less
effective, and that re-localization will appear in both developed and
developing countries. In his view, production will not disappear, but it
will be less labor-intensive, and all countries will eventually need to
rebuild their growth models around digital technologies and the human
capital supporting their deployment and expansion. Spence writes that
"the world we are entering is one in which the most powerful global
flows will be ideas and digital capital, not goods, services, and
traditional capital. Adapting to this will require shifts in mindsets,
policies, investments (especially in human capital), and quite possibly
models of employment and distribution."
Naomi Wu
regards the usage of 3D printing in the Chinese classroom (where rote
memorization is standard) to teach design principles and creativity as
the most exciting recent development of the technology, and more
generally regards 3D printing as being the next desktop publishing revolution.
Environmental change
The
growth of additive manufacturing could have a large impact on the
environment. As opposed to traditional manufacturing, for instance, in
which pieces are cut from larger blocks of material, additive
manufacturing creates products layer-by-layer and prints only relevant
parts, wasting much less material and thus wasting less energy in
producing the raw materials needed. By making only the bare structural necessities of products, additive manufacturing also could make a profound contribution to lightweighting, reducing the energy consumption and greenhouse gas emissions of vehicles and other forms of transportation.
A case study on an airplane component made using additive
manufacturing, for example, found that the component's use saves 63% of
relevant energy and carbon dioxide emissions over the course of the
product's lifetime. In addition, previous life-cycle assessment
of additive manufacturing has estimated that adopting the technology
could further lower carbon dioxide emissions since 3D printing creates
localized production, and products would not need to be transported long
distances to reach their final destination.
Continuing to adopt additive manufacturing does pose some
environmental downsides, however. Despite additive manufacturing
reducing waste from the subtractive manufacturing process by up to 90%,
the additive manufacturing process creates other forms of waste such as
non-recyclable material powders. Additive manufacturing has not yet
reached its theoretical material efficiency potential of 97%, but it may get closer as the technology continues to increase productivity.
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