Detailed Design Review CubeSat Spectroscopy P16104 Team Members - - PowerPoint PPT Presentation

Detailed Design Review

CubeSat Spectroscopy P16104

Team Members

• August Allen
• Andrea Mazzocchi
• Anna Jensen
• Darin Berrigan
• James Lewis
• Mallory Rauch
• Matthew Glazer

Agenda

1. Electrical Engineering Detailed Design 2. Structural Detailed Design 3. Microfluidic Detailed Design 4. Spectroscopy Detailed Design 5. Engineering Requirements with Test Plans 6. Bill of Materials - Updated 7. Risk Analysis - Updated

Electrical Detailed Design

Detecting Emission of Tryptophan

• Sensor must detect tryptophan
• Sensor must distinguish between other

sources

• Output should reflect the tryptophan

intensity, and NOT the UV LED

Responsivity Curve (unfiltered)

Comparison of Filters

• 11.8 mm Unmounted Diameter Filter
• 340 nm centered lense
• 10 nm bandwidth
• Maximum 25% transmission
• Cost: $30
• OD 6 Fluorescence Filter
• 357 nm centered lense
• 44 nm bandwidth
• Maximum 75% transmission
• Cost: $180

Responsivity Curve (filtered)

Hardware - Updated Power Budget

Idle power consumption nearly matched initial assumption. Major change: Solenoid power requirement was greater than expected. Secondary Current Sensor for measuring Solenoid power is an option.

Hardware - Updated Schematic

Hardware - PCB Design

First Revision

• Large amount of free space
• Locations of components likely to change
• Designed for a 10 cm x 10 cm board

Future Revisions

• Add any parts as needed
• Revise board shape, does not conform to standard
• Finalize location of components
• using board as a mounting point
• Secondary board: LED mount/Driver
• will be mounted above sampling area
• dependant on size will include LED driver

Hardware - PCB Design

Cubesat Kit PCB specifications

• used by pumpkin for their kits
• Common platform with future RIT cubesat
• would allow for testing with actual

satellite hardware Power/Data connection PCB

• would allow for simple power and data hookup
• would act as a stand in cubesat bus
• “stretch goal”
• primary focus is on actual experiment

Structural Detailed Design

Chassis

http://www.clyde-space. com/cubesat_shop/structures/1u_struct ures/115_1u-chassis-walls

• 1U Skeletonized Chassis by Pumpkin

Inc.

○ 5052-H32 Aluminum ○ Walls - 1.27mm thick ○ Bases - 1.5mm thick ○ Rated for -40 to +85 °C ○ 97.46mm X 97mm interior

• Meets required NASA standards for

CubeSats as well as different launchers

Walls Bottom Base Lid Rails

Chassis

• The chassis itself is alodyned while the rails are hard anodized. This allows

for the chassis to remain conductive creating a Faraday cage. If the chassis were completely hard anodized, it would become an electrical insulator.

• Able to easily integrate solar panels
• Price - $925.00

○ Unable to manufacture in house due to specialized material treatments ○ A mock-up will be created by CNC milling out of aluminum ○ Will not have the same electrical properties as the original, but will have similar structural properties.

CAD Files

Chassis Walls Bases

Structural Prototyping

Project Requirements:

• The bioassay must fit into a 1U CubeSat.
• The components and sensors of the bioassay are supported by a surrounding

structure.

• As our bioassay develops and changes, so too will the design of the

surrounding structure. Solution: Rapid prototyping techniques such as CNC machining, laser cutting, and 3D printing could potentially allow us to make quick and detailed changes to our CubeSat structure. Currently there have been several uses of additive manufacturing techniques in Cubesats.

Microfluidic Stand

• Initial testing of the solenoids in hand was difficult
• Need a way to keep solenoids in a constant position

relative to the microfluidic device

• Ensures consistent testing
• Easy to print modified stands for future wells
• Gives us an idea of how we will integrate the microfluidic

device into a cubesat.

Solenoid Mounting Test

• Held solenoids in place
• Allowed for easy adjustments
• Ensures consistent results with

all future microfluidic wells.

• Fits into a 1u cubesat

Vibrations - Modal Analysis

Model Analysis

• Using the overall mass and stiffness of a structure model analysis is used to

find the periods at which the structure will naturally resonate.

• NASA CubeSat requirements prohibit 1st resonance frequency to be above

100 Hz

Modeling

Assumptions

• Internal components have been decided on. Shapes and sizes were based off
• f most recent design iteration of microfluidic device.
• CubeSat launched from PicoSatellite Orbital Deployer (P-POD)
• P-POD is constrained along the rails (sides), but it allowed slight movement in

the vertical direction

○ Constrained in both x and y directions and allowed slight freedom in z

Thermal Analysis

• Results

○ Mode 1: 56.271Hz ○ Mode 2: 152.1Hz ○ Mode 3: 156.3Hz ○ Mode 4: 157.75Hz ○ Mode 5: 171.79Hz

• Mode 1 is

significantly lower than 100 Hz. Changes to internal components should not result in drastic changes.

Thermal

• 4 heat sources

○ Direct Solar radiation ○ Albedo (Radiation from sun bounces off earth) ○ Earth Infrared ○ Internal heat generation

• Experimenting with different

ways to incorporate all sources into model

Direct Solar Albedo Infrared http://cdn.phys.org/newman/gfx/news/hires/2013/3-johnshopkins.jpg

Feasibility - Thermal Stability

• Specialized coatings and

materials

○ Allow for increased thermal regulation of vital components ○ Gold plating: high heat retention - α/ε = 10 ○ White paint: low heat retention - α/ε = 0.31

• Experimented with white paint to

discover the effects on temperature

Radiation

• Model created focusing solely on radiation
• 5052-H32 Aluminum material properties used
• Heat Flux of 1W/m^2
• Initial temperature of cubesat of 22°C

1s - No Coating: 21.9°C - 22°C 11hrs - No Coating:

• 28.846°C - -28.72°C

1s - White Paint: 21.5° C - 19.8°C 11hrs - White Paint:

• 20.543°C - -20.391°C

Microfluidic Detailed Design

Improvements Made to Microfluidic Device #2

• Completely remove vibration motor
• Redesign wells and channels to integrate “Push Solenoids”
• Determine new way to mix proteins

○ Use two push solenoids

• Add third well to aid in mixing

Microfluidic Iteration #3

1 2 3

Microfluidic Iteration #3

• Time required for microfluidic device to be built, 1.5 hours
• Testing conducted December 6th
• Improvements recognized for Iteration #4:

○ Larger diameter ■ Allows solenoids to apply greater force ■ Current diameter too small for solenoids to push ○ Reduce height of device ○ Reduce volumes of wells ■ Facilitate reduced height and increased diameter

Spectroscopy Detailed Design

Spectroscopy

• Tryptophan emits 350 nm light when it absorbs 280 nm UV light
• Spectrograph of emitted light will be recorded by a photodiode
• Test early next semester on a protein with tryptophan residues

○ Glass cuvette with protein ○ Device with protein

[1] http://dwb.unl.edu/Teacher/NSF/C08/C08Links/pps99.cryst.bbk.ac.uk/projects/gmocz/fluor.htm

Spectroscopy

• MTE280F13-UV selected as UV-LED from benchmarking

○ Low cost of $147 from Digikey ○ Flat lens with a diameter of 5.9mm ○ Power output of 1.5mW (Ocean Optics Deep UV LED is only 0.5mW)

Looking Forward- MSDII

• Structure

○ All planned components/devices fit within our space constraint ○ Consider using CNC Milling to create a more permanent cubesat prototype ○ Implement final microfluidic design into thermal analysis model

• Electrical

○ Sensors and solenoids interact with microcontroller ○ Test sensor with tryptophan emissions ○ Begin to consider wire and component layout in regards to microfluidic device

• Spectroscopy

○ Responsivity curves for proposed filter look promising ○ Purchase LED and optical filters before winter break ○ Begin testing early in MSDII

Looking Forward Cont.

• Microfluidic Device

○ PDMS iterations have proven to be a quick and effective method of prototyping ○ Need to continue working towards a final design. ○ Must be able to move enough reagent to suspend proteins ○ Test PDMS with UV LED and sensor

Engineering Requirements

Bill of Materials

Risk Analysis

Questions?