design brief - Steven Keating's

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design brief
select projects from steven keating
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(e) stevenk@mit.edu (p) 617 386 3501 (w) stevenkeating.info

outline
a quick introduction…………………………………………………..…..........1
functionally graded 3D printing ……...……………………………..…..….....2
morphable matter …………………………………………………………..…..4
real-life rendering ……...…………………………………………………........7
swarm printing …………………………………………………………………..8
sulico (start-up venture). ………………………………………………….……9
nanocolumn InGaN photovoltaic design …………………………………….10
digitally cleaning ancient artifacts ………..………………………………..…11
films/photography ……………..………………………………………..……...12
side projects ………………………………………………………………….....13

a quick
introduction
Hi, my name is Steven Keating and I am entering my fifth year of graduate studies in Mechanical
Engineering at Massachusetts Institute of Technology (MIT). I’ll try to keep my history brief and let the
projects speak for themselves.
As a child, our basement quickly became the neighborhood electronic facility, much to the chagrin of my
chartered accounting parents. From VCRs to microwave ovens, I took them all apart and was fascinated with
creating new inventions from their components. From Tesla coils to weather balloons to ion motors, my
childhood creations always intrigued my friends and family alike. It was in these early days of tinkering that I
discovered my love for innovation and strong sense of curiosity. In college, I graduated top of my class with
dual undergraduate degrees in Mechanical and Materials Engineering (B.Sc) and Film and Media (B.A.) at
Queen’s University, Canada. While this degree combination of engineering and film may seem unusual, I
believe new perspectives on different fields are an ideal source for innovation. I also draw creative potential
through as many eclectic experiences as I can gather. From teaching product design in Saudi Arabia, to
competing in Peru for the Jr. Pan-American games in badminton, to presenting movies at film festivals in Los
Angeles, I strongly believe in a diverse knowledge base to draw ideas from. Currently, I am working under Dr.
Neri Oxman in the MIT Media Lab working on a range of design ideas surrounding rapid fabrication,
biomimicry, and smart materials.
What follows is a brief selection of my projects. Please feel free to contact me with questions, ideas, or just to
say hi!
Hope you are having a splendid day,
-Steven 1

functionally graded 3D printing
Functionally graded materials, which are materials with spatially varying composition or microstructure, are
omnipresent in nature. From palm trees with radial density gradients, to the spongy trabecular structure of
bone, to the hardness gradient found in many types of beaks, graded materials offer material and structure
efficiency. Yet in man-made structures, such as concrete pillars, materials are typically volumetrically
homogenous. While using homogenous materials allows for ease of production, improvements in strength,
weight, and material usage can be obtained by designing with functionally graded materials. To achieve
graded material objects, we are working to construct a 3D printer capable of dynamic mixing of composition
material. Starting with concrete and UV-curable polymers, we aim to create structures, such as a boneinspired
beam, which have functionally graded materials.
This project is headed by Dr. Neri Oxman and I am the lead graduate student working on the research. We
envision a future where 3D CAD files contain not only geometry and material, but also how that material
varies along the given geometry. By bringing functionally graded materials into digital design, more efficient
and functional use of materials is possible. For instance, take the concrete system we are currently working
on (photo below of samples). By having the ability to control density, aggregate ratio, and water ratio of the
concrete at any given position, we can create graded structures which are lighter, stronger, and use less
material. A good example is the radial density gradient, shown below, which mimics a the cellular structures
of a palm tree and trabecular bone.
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functionally graded 3D printing
To construct the functionally graded 3D printer, we are utilizing a 6-axes robotic arm (bottom left) as a test
platform. The additional 3 axes (traditional 3D printers use only XYZ axes) allow for novel developments in
3D printing which hold great promise, such as pick-and-place embedded printing of parts. Currently, we’ve
developed custom software to run the arm and are successfully able to print plastic objects (top right). By
having exchangeable extruder print heads, we are able to print a variety of materials. To enable functionally
graded printing, we utilize dynamic mixing prior to extrusion. Just like the analogue of mixing paints, we are
able to control output material properties by controlling the mixture of input components. For concrete, we
have constructed an extruder head which mixes a foaming agent with compressed air to give precise control
over the output density. We are currently testing this extruder head and have be able to produce samples
ranging in density from 20 pounds per cubic foot to 100 pounds per cubic foot. For the UV polymer graded
printing, we utilize two polymers with different chain lengths and control the extruded material stiffness by
mixing these two input components.
These design and fabrication tools hold enormous potential in the world of digital fabrication and open new
avenues for functionality of parts. Instead of having two hard plastic pieces hinged together, now a solid
hinge of a more flexible polymer can join the two stiff parts, integrating the functionality into a single
monolithic piece. We are also thinking large-scale. Looking back to nature, we notice a trend of swarm
construction, for example, how miniscule termites work collaboratively to construct massive termite mounds.
We envision the use of swarm printing in the future, where robots can print structures larger than
themselves (bottom right).
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morphable
material
What if a material’s stiffness and geometry can be digitally controlled? Jammable materials offer the ability to
rapidly tune a system’s stiffness, opening a new world of design possibilities.
Granular materials can be put into a jammed state through the
application of pressure to achieve a pseudo-solid material with
controllable rigidity and geometry. This phenomenon occurs in
granular materials when the individual particles are packed
together, causing the friction and Van der Waals forces between
grains to increase. The prototypes in this study have utilized
vacuum pumps to create jammed states through the weight of
the atmosphere on the jammed particles. Depending on the level
of vacuum, the rigidity of the pseudo-solid system can be
manipulated. While jamming principles have been long known,
large-scale applications of jammed structures have not been
significantly explored. As well, potential specific applications are
highlighted and demoed. Such applications range from a
morphable chair, to a flexible vice, to artistic free-form sculpting.
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Seen above is the morphable chair which can be rapidly switched from a very flexible state (top left), to a
sturdy, weight-support state (bottom left) through the jamming effect. Other designs created using this effect
include a universal joint with tuneable stiffness (bottom left) and a jammable vice (bottom right) for holding
objects during machining. These simple systems are extremely cost-effective, novel, and offer significant
potential in a range of applications. A provisional patent has been filed for several of these designs.
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testing and casting with
morphable materials
One of the aims of the research is to provide a
design guide for jammable materials to allow others
to better explore these granular systems. To that
end, much of the work has been in performing
mechanical testing to create guidelines and
strength ratings of different granular systems
(right). We are also investigating the idea of
granular composites, such as mixtures of sand and
jacks, to optimize the jammed strength and
maximize the unjammed flexibility.
The project is exploring additional design avenues
for morphable materials. Picture below is the use of
jammable systems in a casting application. An
object can be rapidly replicated using this
technique, with the additional benefits of easy
demolding and re-usability. As well, lowtemperature
metals can be directly cast with the
use of high temperature silicone elastomers.
Finally, creative applications in art and design are
explored through visual sculptures and the use of
transparent media to create pressure-dependent
light recordings (bottom right). A proof-of-concept
sculpture model is completely self-contained and
can be infinitely re-sculpted, both through its
geometry and light emission.
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eal-life
rendering
Through the use of long-exposure photography, this
project aims to develop a new form of animation where
graphics are rendered in real-life, as opposed to
rendered digitally on a screen. Rendering in reality allows
for real-world input, for example from sensors, to display
environmental data typically invisible to the human eye.
For instance, the photograph in the bottom right shows
the magnetic field lines given off by a laptop. This is
achieved through moving a sensor and light source
through a scene and recording the information through
long-exposure photography. As the sensor informs the
light source, hidden fields, such as radio waves, WiFi
fields, and other fields, become visible in these
photographs. Utilizing a 6-axis robotic arm to precisely
move through the scene allows for detailed volumetric
renderings to be generated. In fact, any 3D shape file in
a computer can be rendered in real-life through this
technique, such as seen in the happy face photograph
above. Films can be made through successively still
frames, generating a new animation form which is a
hybrid of both traditional stop animation and modern
computer graphics.
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Looking to develop additive manufacturing processes on the building-scale offers many challenges. 3D printing
technologies have revolutionized small part prototyping, but scaling to construction-sized objects presents
problems due to cost, speed, and physical size. For instance, to print a office building by simply scaling current
3D printing technologies would require a printer larger than the building itself and would take weeks, if not
months to print.
To solve these problems, an approach has been developed based on natural inspiration of termites. Termites
utilize swarm construction principles to create structures much larger than themselves, up to 30 feet sometimes!
To mimic this approach, small robots have been developed that can print foam structures larger than
themselves. These foam walls dry immediately and can then be filled with concrete to provide a structural wall
element. In additional, the foam molds then act as insulation to provide an insulated concrete building. This
approach is extremely fast, cost effective, and offers complex, non-linear geometries for architecture. To date,
large walls have been successfully printed and a full-scale building is planned for the near future.
swarm
printing
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Sulico is a company started in late 2010 through the MIT course Development Ventures with 5 other
team members. Sulico is a social venture that will provide community-centric solar energy production and
distribute energy as a service for rural Africa. Our vision is to develop generation capacity and
decentralized access that can evolve to form rural electrification systems (micro-grids), starting with
Ghana. By providing energy as a service through community engagement, we present a unique value
proposition that can address the current barrier of affordability and distribution in bringing energy
solutions to West Africa.
Currently, over 40% of Ghanaian households (1.8 million households) still do not have access to
electricity, even though electricity consumption in Ghana has been growing at an annual rate of around
15% annually. These households spend on average $4/month on kerosene for lighting. Moreover, the
lowest income households connected to the electric grid spend on average $5/month (35kWh) for
electricity. These households lacking power corresponds to a total potential annual market between
$85M and $110M.
Site Implementation
Based on the population, the solar irradiance, and grid deployment, Sulico has selected the Eastern part
of the Greater Accra region as the first implementation site. The primary target communities represent
village clusters of around 1,500 households. The typical franchise will be located within the sites that are
central to community life. Sulico will provide the cooperatives with:
• Installation and training: Sulico will procure the hardware necessary and perform the initial
installation. Training will be delivered both on the technical installation and the business operations.
• Maintenance and supply-chain: The local workforce will handle the daily operations, whereas Sulico
will facilitate the planned maintenance and supply chain. This will allow the local partners to focus on
developing the business with the end customers while maintaining an open communication channel with
Sulico.
• Financing package: By partnering with financial institutions such as MFIs (ProCredit) and rural banks
(Shai Rural Bank Ltd), Sulico will allow the local cooperatives to own part of the electricity production
facility (typically 20%).
Sulico has been awarded several grants, inlcluding
a Legatum Center seed grant, and currently has
team members onsite in West Africa testing a trial
run (below).
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digitally cleaning
ancient artifacts
What if you could clean an artifact without having to physical touch it or risk damaging it?
Traditionally, archaeologists have had to balance the use of physical techniques for artifact excavation,
cleaning, and examination with the concern for potential damages to the sample. While this remains true
for excavation, technological advances in non-destructive measurements and imaging techniques have
recently been successfully applied to cultural heritage fields. The use of non-destructive imaging allows
for efficient analysis of samples without the risk of physical damage. My undergraduate thesis work
focused on two of these technologies, x-ray computed tomography (CT) and neutron CT, which offer
three-dimensional imaging capabilities of external and internal artifact features.
The two different scanning techniques were found to compliment each other in analyzing ancient Greco-
Roman coins (from the Diniacopoulos Collection of Queen’s University), as the x-ray contrast is
dependent on the Z-number, while the neutron contrast is dependent on the neutron cross-section. This
work successfully identified numerous corroded ancient coins and the algorithms developed will work for
other metallic artifacts.
For more information, please see:
H. Nguyen, S. Keating, G. Bevan, A. Gabov, M. Daymond, B. Schillinger, A. Muray . (2010)
Seeing through Corrosion: Using Micro-focus X-ray Computed Tomography to Digitally “Clean” Ancient
Bronze Coins. Material Research Society Conference 2010, Material Issues in Art and Archaeology IX
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nanocolumn InGaN photovoltaic design
Currently, the main obstacle to solar panel proliferation is cost. During the summer of 2009, I started work
under Dr. Joshua Pearce looking at ways to improve photovoltaic efficiency and reduce material expenses.
The topic of research was indium gallium nitride (InGaN), which is a new potential photovoltaic material.
Both the optical and structural properties of InGaN were of interest as InGaN has been shown to have a
tuneable band gap (from 0.4 eV to 3.4 eV depending on the indium content). This is an promising material,
as most semiconductors used for solar cells have fixed band gaps and the band gap of a material dictates
what frequencies of light the material can absorb. Most commercial solar cells are single-junction cells,
meaning that only one band gap is used to collect solar energy. Newer, multi-junction cells function similarly
to a stack of single-junction cells, and can collect a wider range of frequencies using different materials for
each junction. These higher efficiencies multi-junction cells currently exist, but are expensive and require
careful processing to get the different materials to have proper lattice matching. InGaN offers a unique
opportunity, as a multi-junction cell could be made with all of the junctions containing InGaN. The different
junctions would only have to have slightly varying compositions of indium to achieve the required varying
band gaps. This means lattice matching would be significantly easier, and the material costs are
inexpensive compared to the high-purity silicon currently used.
While the main driving factor for solar InGaN research is the tuneable band gap, another interesting avenue
is the microstructure. This past summer, my work revealed the nanocolumnar growth present in our method
of InGaN deposition. These nanocolumns offer an interesting method to easily creating a three-dimensional
solar cell. If the columnar structure could be maintained in a solar cell, the extra surface area and reflection
properties will improve absorption and efficiency when compared to the standard planar geometry. The
photos below detail the nanocolumnar structure observed in our deposited InGaN samples. My work
discovered these structures (seen below in scanning electron microscopy), linked their crystallinity to the
indium content, and modeled a multi-junction photovoltaic cell around this tuneable band gap
semiconductor.
For more information, please see our recently published paper:
S. Keating, M. G. Urquhart, D. V. P. McLaughlin, and J. M. Pearce. (2011)
Effects of Substrate Temperature on Indium Gallium Nitride Nanocolumn Crystal Growth. Crystal Growth
and Design. V.11, Pg. 565-568
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side
projects
film
I am an avid photographer and video enthusiast and I often
build side projects around film. Past work has included many
short films, commercials, education videos and documentaries.
I highly subscribe to the power of visuals for communication
and evocating emotion. Some of my work can be viewed online
at www.stevenkeating.info.
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tinkering
It is hard to group all of the past side projects I’ve embarked on;
ranging from homemade night vision (below), to radio trackers (top
right), to careening down hills on a homemade street luge (middle
right. I can best describe it as a passion for curiosity and inventing,
or tinkering. Another good example is a amateur radio weather
balloon project where a homemade GPS transmitter and camera
was attached to a salvaged military weather balloon (bottom right).
One of the latest project I have embarked on is an underwater robot
capable of diving full ocean depth (over 6 miles deep). By using a
novel pressure-tolerant design and homemade sensors, a cost
under $100 was maintained.
These small projects may seem all different, but the unifying theme
is of innovation and design. While these projects are entertaining,
they also allow me to quickly explore areas that could lead to future
research. The morphable materials project grew out of a quick side
experiment and is now a full-fledged project.
side
projects
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