3D Printing Devices From Principles to Application

3D Printing Devices
From Principles to Application
Dr Daniel J. Thomas
daniel.thomas@engineer.com

Content
• A Brief History of 3D Printing.
• 3D Printing Technologies.
• 3D Printing Bio-plastics.
• Sensors.
• Optical Fibres.
• Carbon Fibre Systems.
• Thermo-chromic Materials.
• 3D Printing Foods.
• 3D Printed Circuit Boards.
• Conclusions.

3D Printing
• 3D Printing is NOW a rapidly evolving technology consisting
of many different methods for fabricating a new generation of
advanced components and structures.
• The most important aspect of this technology is that 3D
Printing becomes a sustainable, scalable and viable future
manufacturing method.
• Research focuses on making complex components from a
range of innovative and functional materials. These are being
used to make new machines and functioning devices.
• This lecture will consider the different 3D Printing technologies
being developed.

The Beginning of 3D Printing
In 1981, Hideo Kodama of Nagoya
Municipal Industrial Research Institute
invented two AM fabricating methods
of a three-dimensional plastic model
with photo-hardening polymer, where
the UV exposure area is controlled by
a mask pattern or the scanning fiber
transmitter.
Then in 1984, Chuck Hull developed a prototype system based on this
process known as stereolithography, in which layers are added by
curing photopolymers with ultraviolet light lasers.

2012 – A key year for the technology.
1) Engineers figure out ways around 3D Systems Patents SLA
and start manufacturing machines for a fraction of the price.
2) The same happened to Stratasys FDM technology.
3) Massive insurgence of smaller companies which were able to
engineer small smart systems for the general consumer
market.
4) The World begins to take an interest in this new technology.
5) China becomes a major manufacturer of machines which not
only have reduced the cost but also increases quality.

In 2015 there are approximately 550 different manufacturers 80% of these are
in China.

How does 3D
Printing Change
the World?

People think that 3D Printing will only be a low
volume manufacturing process. But can it be
something more?

Relatively simple
Homogenous
No/few components
Mechanical
properties not critical

Unlimited Scale

What does 3D Printing Mean?
• As soon as people can turn a computer file into a useful
solid object, those computer files then become a product.
• But we live in the world of free, nobody will buy something
that they can get for free next door.
• This provides an interesting concept – who picks up the
bill?
• Thus we are moving into a design economy. This is where
is doesn’t take skill to build a product and the rate at which
new products are introduced increases exponentially. New
industries formed, new companies built…and all resulting in
a less predictable future.

Material Extrusion (FDM)
• Most common 3D Printing technology
• Desktop models are now very
widespread
• First £150,000 (2010) £2000 (2012)
£500 (2014) £225 (2015)
• Massive influx of Chinese
Manufacturers.

• Fused Deposition 3D Printing is a process of
making a three-dimensional object by laying down
and fusing materials together. This 3D Printing
technology is the most flexible, low cost and
popular method of 3D Printing today.

High Precision 3D-Printing
• Controlling the deposition properties allows for the accuracy
of objects to be increased almost exponentially.
• This process has been developed to make low volume high
impact components.
• Research has been successful in producing low price high
accuracy surgical replicas.
D J. Thomas, M.A.B. Mohd Azmi, Z. Tehhani (2014) 3D Additive Manufacture of Oral and Maxillofacial
Surgical Models for Preoperative Planning. International Journal of Advanced Manufacturing Technology.

Polymer Knee implant
Rebuilding Joints
• In order to rebuild joints then we need to integrate suitable polymer
in order to aid stability and couple this with a durable permanent
implant.
• This has been found in a 3D printable material ‘Nylon 645’ which at
320MPa UTS is pound for pound stronger than Titanium alloy.

Critical Characteristics
The two most critical factors to control carefully in
3D Printing are the layer resolution and the
deposition of the exterior shell.
It are these two significant properties which
controls the edge and surface accuracy.

These Scanning Electron Micrographs show an
FDM Printed structure – here 50µm layers (half
a human hair) were printed to produce high
definition structures.

Integrating Thermoplastic Elastomers
Custom and highly functionalised 3D Printable TPEs are being formulated
so that they comply with ISO 10993 biocompatibility standards.
Applications include:
• Artificial fillers
• Tubing
• Catheters
• Drug delivery devices
By combining composite materials
then we can make hybrid implants
which are patient specific.
With future development we plan to
integrate memory polymers into these
devices to make moving parts –
valves.

Material Jetting
• More professional
prototypes
• Multi-material
• Common in design firms

Piston raises for
the next layer,
powder is spread
over the build
area, enough for
one layer.
Standard inkjet
printhead
Roller spreads
a layer of
powder
Feed Build
Piston lowers
platform for a
new layer

• The 3D binderjet prints one layer at a time, much like 2D
printing. Liquid binder is used in place of ink to bond a
coloured powder.
• The build platform drops one layer at a time so that a new
layer of powder is spread out and the machine prints the
next layer.
• This process repeats, layer
by layer, until the model is
complete. This process is
capable of making multi-
coloured moving parts
How this process works

Concept Modeling
Printing Time: 24
Consumer Products
Printing Time: 6 hours
Medical
Footwear
Automotive

Vat Polymerisation (SLA)
• Oldest 3D Printing
technology
• High resolution but relatively
low strength parts
• New desktop versions
available

• Photo sensitive resin printers are the vanguard of
3D Printing technology, producing 10-25µm layers
to a high degree of precision.
• The technology uses one whole layer curing at a
time.
• This technology can be used to produce high
resolution and high quality parts for biomedical
applications or integrated moving parts.
3D Light polymerising Printers

• Tank of liquid polymer
• Polymerize (harden) with laser
beam
• Latest technology MEMS to
expose 84,000 pixels at once.
Large SLA Systems

• This process uses blue UV light
from a Digital Light
Processing source to cure
whole layers of photo sensitive
polymers.
• This process can be quite
complex to engineer and is
generally higher cost due to
the high price of the resins.
• But, for high-end applications
this process results in the
production of a professional
standard.
Low cost SLA for schools

• Photo polymerising resin technology is going to be
developed to make high resolution objects with
layers of polymers and electrically conductive
polymer connections.
• This is a process which can be used to produce the
microfluidic component with integrated electrical
connections.
Initial 3D Printed parts
Light Polymerising Sensors

Directed Energy Deposition
• Electron Beam Melting
• Medical and Aerospace
• Alloy components

3D Printing Data Acquisition
• 3D Design Software
 MeshLab – Difficult
 3DS Max – Quite difficult
 Autodesk Inventor - Medium
 Blender – Easy
 Google SketchUp – Very Easy
• STL file to g code conversion
software, pronterface, replicatorG
and CURA.
• Laser scanned data

First generation
software was
based on two
tools.
Pronterface and Slicer
These were
very complex to
use and
generally only
used by expert
users

This evolved into ReplicatorG which became easier to use
and generated thousands of lines of Gcode automatically.

Printing an Object in 3D
In order to produce structures then the process
parameters need to be altered. This resulted in Cura.

Making an Object in 3D
• Starting from a computer aided design this is converted
to a standard triangulation language (.stl) file.
• This is converted into a tool path (g code) which
accounts for our process parameters.
• Using extrusion processes then complex components
can be produced to a ±25μm degree of accuracy at
50μm layers.

Overview of the Market
• Additive Manufacturing is currently a $6 billion industry worldwide.
• Market is expected to double by 2018 to roughly $12 billion.
 Context: Injection molding market expected to be $252 billion in 2018
• Sales for low cost machines (<$5000) – 35,508 in 2012
• Sales for professional machines (>$5000) – 6,494 in 2012
Data: Wohler’s Report

Challenges with 3D Printing
• Limited and high cost of materials
• Unreliability of machines
 20% reject rate
• Challenges scaling up technology
• Speed
• IP – who owns it?
• Environmental Concerns
• Surface finish
• Resolution
• Mechanical properties
• Parts require extensive post processing

Materials
• Plastics:
 PLA
 ABS
 PC
 Poly Wood
 PMMA
• Metals:
 Stainless steel
 Titanium
 Aluminide
• Glass
• Ceramics
• Photo Resin
• Sandstone
• Cement
• Conductive
• Chocolate
• Rubber
• Biologically Active Materials
Combined colour and different materials 3D Printing.

Bioplastics
• This is working to develop processes to make
components from controllable biodegradable polymers.
• These poly-lactic-acid based materials can be
controlled to degrade at a predictable rate. This could
allow us to make parts which controllably dissolve when
they are disposed with different curing agents.
• For this we need to use a special nozzle and in-situ
cooling system in order not damage the polymer.

Material Additions
• By putting different powders or
particles into a PLA polymer then
we can 3D Print components with
desirable structural and aesthetic
properties.
• It was this research which also
allowed for more realistic objects
to be 3D printed with different
contrasts and texture…cheaply
Brass NaturalTimberCeramic Titanium

Optical Fibres
• By 3D Printing PMMA-based optical fibres at low cost then
we can make integrated optical communication systems.
• This can be used to build optical fibre backbones to transmit
communications through on a circuit board or produce
unique 3D optical fibres on demand.
• We need to carefully control the drive wheel and the
temperature so as not to damage the fibre as it is deposited.

3D Printed Circuit Boards
• Recent work has focused on the development 3D
Printed circuit boards made from carbomorph which is a
combination of carbon conductive filler and
polycaprolactone to form a conductive matrix polymer.
• Carbomorph polymer is both conductive, temperature
and moisture sensitive and piezo-conductive, in which
circuit boards and touch-sensitive components can be
integrated together in the form of 3D-printed objects.

Devices as Circuit Boards
• Because of these properties, solid state force
feedback devices can be constructed.
• An example of this is a lead screw which can detect
torque, temperature and subsequently if it is touching
a liquid and feedback stress during rotation.
• As a result, devices become their own circuit boards.
Another example of this is an egg cup that can tell
when it has an egg in it or even the weight of the egg.

Advanced 3D Printed Sensors
• Currently this is being developed to make a special
sensor that is made up of individual lines of
conductive polymer which is embedded into a system,
• These encapsulate a PMMA fibre optic core. This can
be used to indicate stress and strain when a machine
is distorted.
Carbomorph
Polymer
3D printed PMMA fibre optic
core 5MHz @ 650 nm

Carbon Fibre
• By working with tenax carbon then we can make a
carbon fibre filament and subsequently high strength
and conductive components.
• The good thing with carbon-based polymer composites
is that we can make lightweight custom structures.
• Applications such as Cams for compound bows and
nocks for arrows are two such current applications
which are being developed at the moment.

Printing Integrated Machines
• By carefully controlling the process parameters then
we can build integrated machines.
• This research focuses on finding ways to automate
the design and subsequently fabrication process.
• Using shape memory polymers we can print origami
inspired machines that are 3D printed flat and then
they self assemble themselves into actual parts.
Integrated parts Separate parts Moving parts

Conclusions
• 3D Printing Technology is accelerating at an
increasing rate, while quality, speed and
performance is developing month-on-month.
• The cost of making components is reducing
greatly as is the cost of equipment. By the end of
2015 the price of 3D Printing machines will be on
par to that of home laser printers.
• There are an abundant number of materials
becoming available, allowing for fascinating new
structures being developed.
• New untraditional ultra-efficient distributed
manufacturing industries are starting to evolve,
so called the third industrial revolution.

Dr Daniel Thomas
3Dynamic Systems

3D Printing Devices From Principles to Application

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