Guidelines for the EMS5NME Group Project
Prof. J. L. Maxwell
Section I: Introduction
Please select one topic from the ideas in Section III below. This is a microfabrication or
nanomaterials project that will require engineering design skills. You will need to be
familiar with the nano/micro fabrication processes needed to manufacture all components
of your project, and you will need to describe the process sequence(s) for producing each
component.
All projects listed in Section III provide some form of technical support to the HAAMER
project. This project involves a high-altitude balloon system that La Trobe University is
developing. If you are unfamiliar with the HAAMER Project, please refer to an overview
that will be posted on the LMS site in the EMS5NME/Group Project folder.
How You Should Approach This Project:
This project will teach you to: (1) identify the challenges associated with your project topic
(i.e. define the problem), (2) search in the literature for what others have done, (3) use
creativity and brainstorming to find your own solutions, (4) evaluate your solutions and
perform calculations to see if your solution should work, and then (5) further develop this
solution, adding important details, e.g. dimensions, tolerances, materials, CAD drawings,
etc. It is assumed that at least one member of your team is capable of creating computergenerated engineering drawings. Finally, during step (6), you will communicate this
selected design and summarize your work by generating a group project report. In other
words, you will be following the engineering design process given below (Fig. 1), from the
onset to the end of the project, while skipping the testing and iteration steps (for lack of time
to carry these out).
Fig. 1: Elements of the Engineering Design Process (Source: youtube.com)
Section II: Project Requirements
Things you will need to complete for your project:
• Form a team of at most three individuals in LMS. If you don’t know anyone, the
teaching assistant(s) will help to team you up.
• Arrange how you will work electronically with these individuals–without any direct
personal contact (exchange phone numbers, emails, arrange Zoom meeting IDs, etc.).
If you can’t contact these individuals, please email the teaching assistants.
• Divide the design engineering and report writing tasks evenly amongst yourselves, so
no one person has too much to do.
• Meet electronically for each phase of the design project (each step in Fig. 1).
• Brainstorm your collective ideas, document them, analyse them, and choose the
winning design.
• Justify your choice for this solution by providing calculations of its anticipated
performance.
• Put additional details into your design choice. This should include engineering
drawings with dimensions, tolerances, and materials for each component.
• Provide detailed CAD drawings with dimensions for each element (your own work).
• Explain how you would minimize mass by microfabricating each component.
• Provide a “workable process sequence” to fabricate each component, or, if nanomaterials, the processes required to synthesize these materials.
• Determine the final assembled mass of your system.
• Write a final report, as described below. Each individual is required to write at least
two sections of the final report. The author’s name must appear in the header of the
pages that he/she wrote. The final report must be uploaded as a single document into
LMS by one group member. 50% of your report grade will be based on your individual
contribution, based on what we see written by you (no name, no credit).
Your proposed solution must meet the performance criteria provided in Section III, while
minimizing the mass (or cost) of your solution. You will be graded on how well you
minimize mass (or cost) yet achieve the performance goal. You will also be graded on the
appropriate use of microfabrication processing sequences to fabricate your system
components. Depending on your project, a few components may be exempt from the
nano/micro fabrication requirement, as determined by Prof. Maxwell. Please check for
proper English grammar and word usage.
Final Report:
You will need to write a final report to communicate your solution. It should be in the
following format, with the given bolded headings:
1. Introduction to the project/problem (1) page: Assume we know about the HAAMER
project, but we need to be told what problem(s) you are solving for this project.
2. Identify Engineering Constraints to your solution (1/2 page): Tell us what the
boundary conditions are, limits on the design, what performance your solution should
have, and what the priorities or criteria for selecting your design are.
3. Potential Design Solutions: Provide ≥3 possible solutions (<2 pages with figures).
Describe the solution to us in a way that anyone can understand. You should provide
figures/sketches of your rough ideas, but make sure the figures are not too large on the
page.
4. Your Selected Design (1 page): Tell us your winning solution, and why you selected
it, using calculations of expected performance to back you up. It is very important that
you use quantitative methods to make this decision. What makes you think this design
will work? No more than one sketch or drawing should appear here.
5. Detailed description of the design (<3 pages with calculations and drawings): Add
important details into your winning solution. How will all the parts go together? What
is their geometry? What materials are you using? How strong are the materials, given
the thicknesses you are using? Can they take the forces you are assuming (back this up
with calculations or FEA)? What currents/voltages will you be dealing with? Are all
conductors spaced so they will not short out? Etc.
6. Fabrication Methods: Tell us how you would nano/micro fabricate these parts and
assemble them. You must provide fabrication sequences for each component. (<2
pages, including figures)
7. Conclusions: Describe the expected performance quantitatively. How do you think
this design will perform? (1/2 page)
8. References: Must have at least 12 references from archival journals. Only three of
these references may be from a website URL. Use the La Trobe Library search engine
to find these. (This is not included in the page count)
Important:
The report must be at most 10 pages (excluding references), single-spaced, Times New
Roman, 10-point font, with figures taking no more than 1/3 of the space on any page. Please
do not try to fill space with unnecessary figures, and do not leave any large blank spaces in
the document. Please upload the report into LMS as a PDF document. You must have at
least 12 references. Many points will be deducted for not following this guidance.
Additional bonus points will be given for a well-written, easy-to-read, information-packed
report.
Things you will not need to do:
• Make any actual prototypes.
• Perform any nano/micro fabrication yourselves.
• Test any actual prototypes.
• Design any control electronics or software.
Things you must NOT do:
• Copy any drawings from the internet into your final report.
• Use any text from sources other than your own mind. No plagiarism.
• Use anyone else’s designs, drawings, or calculations; if the same material appears in
two or more groups reports, both groups will receive a failing grade for cheating. (So,
keep your designs confidential.)
Section III: Possible Group Design Projects:
(Please Choose ONE)
1. Electrohydrodynamic Thrusters for HAAMER:
Electrohydrodynamic thrusters use high voltages to create ions and accelerate them past
grids to achieve propulsion. The ions’ collisions accelerate the air around them and generate
thrust. For some nifty examples, please see URLs:
https://people.eecs.berkeley.edu/~ddrew73/files/RAL18.pdf
http://www.technovelgy.com/ct/Science-Fiction-News.asp?NewsNum=5591
Assumptions/Design Limits:
–Grids and all supporting components, including wiring, must be microfabricated.
–Assumes a high voltage power source is available that makes it work.
–Assumes 6+ separate units will be needed for all axes.
–You will need to provide grids large enough to achieve the necessary thrust.
–Mass must be determined and minimized!
Performance Criteria:
–Your design must be able to stop the rotation of a floating 3kg sphere that is 10cm in
diameter within 3 minutes. The sphere is initially rotating about a vertical axis at 0.05 Hz
(1/20th of a rotation per second).
–Provide calculations showing that the thrust you generate is sufficient to stop the sphere
from rotating in 3 min.
–Provide energy calculations showing how much stored energy will be needed to repeatedly
stop such a sphere from moving over the course of an hour (once it stops, the scenario
resets to the initial rotational velocity).
2. Microfluidic Rocket Thruster for HAAMER:
Small satellite thrusters have been microfabricated for over 20 years, with arrays of solid
propellants that are individually ignited when needed. The thrust over time is achieved by
sequentially firing individual propellant cells. Check out examples at:
L. Jongkwang, K. Taegyu, “MEMS solid propellant thruster array with micro membrane
igniter,” Sensors and Actuators A, 190 (2013) 52-60.
https://iopscience-iop-org.ez.library.latrobe.edu.au/article/10.1088/0960-
1317/22/9/094004/pdf
Assumptions/Design Limits:
–Uses microfabricated wells or capsules for specific impulses.
–Assume you will make an array with thousands of wells/capsules.
–Must have one common exit channel and thruster nozzle.
–Assume 6+ separate units will be needed for all axes.
–Mass must be determined and minimized!
Performance Criteria:
–Your design must be able to stop the rotation of a floating 3kg sphere that is 10cm in
diameter within 3 minutes. The sphere is initially rotating about a vertical axis at 0.05 Hz
(1/20th of a rotation per second).
–Provide calculations showing that the thrust you generate is sufficient to stop the sphere
from rotating in 3 min.
–Provide energy calculations showing how much stored energy (J), in the form of grams of
fuel, explosives, etc. will be needed to continually stop such a sphere from moving over the
course of an hour (once it stops, the scenario resets to the initial rotational velocity).
3. High-altitude Micro-actuated Wind Vane Arrays:
Assuming wind is flowing past the balloon, it should be possible to control orientation of the
sphere by using wind vane arrays (similar to a windmill). With several vane arrays around
the sphere, multiple wind directions can be accommodated. By opening/closing some vane
flappers in an array, the wind drag at any array can be decreased/increased. The open cross
section facing the wind determines the wind drag; this force can be used to control the
sphere’s orientation. A related example can be seen in:
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.662.8684&rep=rep1&type=pdf
Assumptions/Design Limits:
–Assume relative constant wind velocities flowing past the wind vane arrays at 2.2 m/s.
–Assume 3+ separate units will be needed for stabilization.
–All components of the array must be nano/micro fabricated.
–Mass must be determined and minimized!
–Look up examples of various microactuators in the literature to move the vane flappers.
Performance Criteria:
–Your design must be able to stop the rotation of a floating 3kg sphere that is 10cm in
diameter within 3 minutes. The sphere is initially rotating about a vertical axis at 0.05 Hz
(1/20th of a rotation per second).
–Provide calculations showing that the drag force you generate is sufficient to stop the sphere
from rotating in 3 min. Scale your array to achieve this.
–Provide energy calculations showing how much stored energy (J) will be needed to control
the array flappers and continually stop such a sphere from moving over the course of an
hour (once it stops, the scenario resets to the initial rotational velocity).
–Mass must be minimized! Remove all unnecessary mass.
4. Truss Design for High-Altitude Scheifspiegler Telescope:
A high-altitude telescope will be built and mounted to the HAAMER balloon system. It will
be positioned horizontally, as shown in the figure below, and hangs at its centre of mass
from the pivot shown. The goal is to maintain the primary mirror’s position relative to the
secondary mirror over time, without sagging. The mirrors are round with a given thickness
and mass. The light paths cannot be obstructed at any time.
High-Altitude Scheifspeigler Telescope-Truss Illustration
Assumptions/Design Limits:
–Your job is (only) to design the telescope truss that holds the mirrors.
–The primary mirror’s mass is 25g, while the secondary mirror’s mass is 6 g.
–The primary mirror is 150mm in diameter and 6mm thick, while the secondary mirror is
75mm in diameter and 4mm thick.
–The primary mirror must be precisely 2.4 meters from the secondary mirror.
–You can use “Roark’s Formulas for Stress and Strain” to estimate the bending of the truss
(in the plane of the drawing), or a FEA analysis, as desired.
–The mirrors both have a spherical curve to their reflective surfaces, and make up a
Schiefspiegler optical design, as described in: https://en.wikipedia.org/wiki/Schiefspiegler.
–All components of the truss must be nano/micro fabricated to achieve their shape.
–You can remove any material that is not necessary to maintain stiffness in the truss design.
Performance Criteria:
–Neither optic can be displaced (downward) by more than 0.5mm under gravity when
hanging from the pivot point, so the truss must be very stiff.
–This is a 3-D truss problem, not just a 2-D truss problem. The stiffness of the truss (in-out
of the plane) must be at least 0.3x the stiffness of the truss in the plane. You must design
any “cross-bars” or plates also.
–You must minimize the mass, while not sacrificing too much stiffness.
5. Low-cost, Rapid Charge, High-Capacity Microfabricated Salt-Water Batteries:
These are custom batteries that will ultimately be assembled within a 200 litre drum—which
must use an aqueous electrolyte. These batteries are for HAAMER ground support. They
will need to charge and discharge as rapidly as possible, but they should also have the greatest
capacity possible. The design should be simple using easy to purchase components. For a
starting point, please see the following references:
https://www.youtube.com/watch?v=1EhnmWo2CZ8
https://www.youtube.com/watch?v=HmtI8Wat7rY
A. Armutlulu, S. Allen, M. Allen, M., “Microfabricated nickel-based electrodes for highpower battery applications,” Journal of Micromechanics and Microengineering, 23, (2013),
4008-.
https://patents.google.com/patent/US6228527B1/en?q=saltwater+battery&assignee=The+U
nited+States+Of+America+As+Represented+By+The+Secretary+Of+The+Navy
https://patentimages.storage.googleapis.com/12/0a/06/28add71409016f/US6714402.pdf
https://patents.google.com/patent/US3148090
V. Piotter, E. Honza, E., et al., “Replication processes for metal and ceramic micro parts,”
Microsystem Technologies, 20, (2013), 2011-2016.
Assumptions/Design Limits:
–Everything fits within a 200 litre drum.
–Must provide the maximum energy storage (J) possible with safe, low-cost components.
–No lithium or lead allowed.
–Maximizes how quickly the battery can be charged/discharged by using nano materials
and/or microfabricated components.
–Minimizes the use of precious metals (anything more expensive than silver).
–The drum and electrolyte are exempt from the microfabrication requirement. All other
components must be microfabricated and/or synthesized.
–PCB boards are allowed.
Performance Criteria:
–Cost is the primary driver.
–Capacity is the secondary driver. Maximize energy storage in a 200 litre drum.
–Use of only safe, non-flammable materials is the third priority.
–Use only easy to obtain (commercially-available) materials.
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