• Technical
• Problem Definition
• Social
• Figure of Merit
• Political
• System Design
• Economic
• Constraints, Tradeoffs
• Statistics of Variation
• Tolerance, Capability
3.003
Principles of Engineering Practice
Research Methodology (10min)
The Ethical Engineer (30min)
Light-Matter Interactions (10min)
Laboratory Methodology
The Complete Engineer’s Skill Set
Technical—Social—Political--Economic
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Problem Definition
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Constraints
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Options
�
Analysis
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Solution
3.003 Technology Problems
The Complete Engineer’s Skill Set
Technical—Social—Political--Economic
Add the following to your lab report.
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Problem Definition
�
What problem is the team solving?
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Experiment Design
�
What are the constraints that the team
faces?
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Solution
�
�
3.003 Technology Problems
The Complete Engineer’s Skill Set
Technical—Social—Political--Economic
�
Problem Definition
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Attributes, Specifications
�
Design
�
Constraints
Figure of Merit: Tradeoffs
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Options
�
Analysis
Statistics of Variation: Tolerance, Capability
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Solution
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Figure of Merit
materials selection
Materials Design
Property relation to Performance
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Example: problem and constraint
load bearing with lightest weight
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Volume = LxA
�
P = load
(1/m)
max
= Performance
Materials Properties
�
tensile strength =
σ = P/A=load/area
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m = density x volume =
ρAL
1/m =
σ/ρ x 1/PL
An Ethical Engineer?
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Conflicting motivations
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divergence between commerce and
engineering?
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is the data sufficient?
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Ethical action
�
most good for most people?
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absolute right and wrong?
Laboratory Methodology
The Complete Engineer’s Skill Set
Technical—Social—Political--Economic
�
Problem Definition
�
Constraints
�
Options
�
Analysis
�
Solution
Ethics Basics
�
Absolute of Judgment?
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Rationale: good world or self?
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Truth = ‘fuel of the mind’
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science of variation
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Can sustainability be built on fiction?
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Ethics is not an act, but a lifetime; it is the
The Puzzle of Moral Judgment
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Kant
�
Right
is
principles that everyone can follow
.
�
Mill
�
Right
is the
greatest good for the greatest
number of people
.
Ethics: Private vs. Public
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Your purpose in life
Ethics: Private vs. Public
HYPOTHESIS OR FACT?
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The way that you live has consequences
Light is an Electromagnetic Wave
Observables
Photonic Materials
Electromagnetic Field
�
dielectric constant,
ε/ε
0
�
voltage
�
index of refraction,
n
�
current
�
absorption,
α
�
wavelength,
λ
�
group velocity,
v
g
= c
o
/N; N = group index
�
power,
P
c
material
= c
0
/n
r
n
r
= (
ε/ε
0
)
1/2
(static)
n (
υ)
Si
11.7
3.5
Ge
16
4
LiNbO
3
43
2.27
BaTiO
3
3600
2.46
Materials Design by Property Maps
CN = 8
CN = 6
CN = 4 (ZB)
CN = 4 (W)
Hybridization energy
Electronegativity difference
In
de
x
of
re
fr
ac
tio
n
D
ie
le
ct
ric
c
on
st
an
t
M
el
tin
g
po
in
t
La
tti
ce
p
ar
am
et
er
A
ve
ra
ge
p
rin
ci
pa
l q
ua
nt
um
n
um
be
r
Energy gap
Carrier mobility
ionicity
metallicity
hardness
Metal
Insulator
Lab #1 Appendix 1
Optical absorption of water
Solar spectrum
From Haug, Franz-Josef. "
Irradiation Spectrum
." Solar Cells: Generating Electricity from Light.
Used with permission.
Refractive indices
Material Refractive
index
Air 1.0
Water 1.33
SiO
2
1.5
Si
3
N
4
2.0
Anti-reflection (AR) coatings
Elimination of reflection on surfaces:
� Solar cells
� Photodetectors
� Photolithography
SiO
2
-on-Si Color Chart
0.05 0.07 0.10 0.12 0.15 0.17 0.20 0.22 0.25 0.27 0.30 0.31 0.32 0.34 0.35 0.36 0.37 0.39 0.41 0.42 0.44 0.46 0.47 0.48 0.49 0.50 0.52 0.54 0.56 0.57 0.58 0.60 0.63 0.68 0.72 0.77 0.80 0.82 0.85 0.86 0.87 0.89 0.92 0.95 0.97 0.99 1.00 1.02 1.05 1.06 1.07 1.10 1.11 1.12 1.18 1.19 1.21 1.24 1.25 1.28 1.32 1.40 1.45 1.46 1.50 1.54 Dull yellow-green Yellow to "yellowish" Orange Carnation pink Violet-red Red-violet Violet Blue-violet Green Yellow-green Green Violet Red-violet Orange "Yellowish" Sky blue to green-blue Orange Violet Blue-violet Blue Dull yellow-green Violet-redCarnation pink to salmon Tan
Brown
Dark violet to red-violet Royal blue
Light blue to metallic blue Metallic to very light yellow-green Light gold to yellow - slightly metallic Gold with slight yellow-orange Orange to melon Red-violet Blue to violet-blue Light green Green to yellow-green Yellow-green Green-yellow Yellow Light orange Carnation pink Violet-red Blue
Blue to blue green
Red-violet Violet Blue-violet Blue Blue-green Green (broad) Yellow-green Green-yellow
Light-orange or yellow to pink borderline Carnation pink
Blue-green to green (quite broad) "Yellowish"
Orange (rather broad for orange) Salmon
Dull, light red-violet Violet Blue-violet Blue Blue-green Violet-red Yellow to "yellowish" "Bluish" Film thickness, microns Film thickness, microns
Color and comment Color and comment
