Microbial Detection Arrays

Microbial Detection Arrays
MiDAs October 23rd, 2006 Aerospace Senior Projects University of Colorado - Boulder

Team Members Elizabeth Newton – Project Manager
Shayla Stewart – Systems Engineer Steven To – Chief Financial Officer Dave Miller – Fabrication Engineer Ted Schumacher – Lead Thermal Engineer Jeff Childers – Lead Structural Engineer Charles Vaughan – Lead Electrical Engineer Sameera Wijesinghe - Webmaster

Look for me for further info
Briefing Overview Jump to Overall Objectives System Design Alternatives Design-To Specifications Thermal Design Options Structural Design Options Electrical Design Options Project Feasibility and Risk Project Plan Appendices Look for me for further info

Picture from www.physics.byu.edu
Overall Objectives Picture from

Objectives Overview Objective: To design and build a field-ready unit capable of providing a testing environment for electrochemical sensors to detect microbial life by soil analysis Deliverables: Field-ready unit Test data verifying requirements Operational manual for use Electrochemical sensors Sensors developed by Tufts University and BioServe Sensors analyze soil for metabolic indicators such as pH and chemical composition and convert them to electronic signals Assumes that life only needs water and nutrients found in native soil to metabolize

Data Acquisition and Control
Functional Diagram Geological Sample Soil Sterilization Temperature Control Test Chamber Control Chamber Inoculation Sample Reagent Water Sensors Data Acquisition and Control Power Mixer Accept soil Sterilize soil using an autoclave Add reagent water Move soil to reaction chambers Add non-sterile inoculation sample to test chamber Mix soil and water while starting temperature control Testing lasts for two weeks

Functional Requirements
Must be capable of performing in extreme Earth conditions McMurdo Bay, Antarctica -10°C to 2°C (during summer) Atacama Valley, Chile -6°C to 38°C Must provide and function with power comparable to next-generation Mars science rovers (30 Watts) Must be portable (30 kg) Pictures from Wikipedia.org

Assessment of System Design Alternatives
Quantitative analysis of cost, mass, and volume based on rough estimates Ultimately, complexity became primary consideration Pro -Reaction chambers at same temperature -No need to heat/cool each chamber individually Con -No way to correct if one chamber is warmer than the other -More volume to heat/cool Pro -No need for extra environmental chamber Con -Each reaction chamber must be heated/insulated Shared Environmental Controls Pro -Only one chamber must be fabricated -Only needs one heater Con -Soil must be separated into test/control chambers after sterilization Overall Architecture: Separate Shared Environment Separate Sterilization Chambers Shared Pro -No need for soil separation: reduced complexity Con -Two chambers and two heaters Sterilization Chamber Separate

System Design Alternatives
End Result Separate Autoclaves Shared Environment

Design-To Specifications
Thermal Subsystem Mass: 16.3 kg Volume: m3 Cost: $660 Structural Subsystem (excluding chassis) Mass: 11.3 kg Volume: m3 Cost: $280 Electrical Subsystem (excluding power supply) Mass:0.30 kg Volume: m3 Cost:$1340 Overall System Mass:27.9 kg Volume: m3 Cost:$2280 Total Funds: $8000

Overall System Architecture
Autoclaves Water Chamber Pump Inoculation Chamber Test Chambers DAQ/Power TEC

Work Breakdown Structure

Thermal Design Options
Pictures from melcor.com, minco.com, wikipedia.org, energysolutionscenter.org

Insulation Options Insulation applications Autoclave chambers
Environmental chambers Reagent water chamber Inoculation sample chamber Insulation Requirements Minimize power needed to heat chambers Protect electrochemical sensors from heaters Criteria (order of importance) 1. Volume (thermal conductivity, k) 2. Complexity 3. Cost

Insulation Option Pros and Cons
Silica Aerogel -Very low thermal conductivity -Expensive Thermal Coat - Ceramic -Moisture resistant -Adds almost no volume because it is painted on -Complicated application Fiber Board (Sindayno) -350 -Very low density -Thermal conductivity is higher than that of air Additional Options for Heating and Cooling

Structural Design Options
Pictures from trendir.com, polypenco.co.jp, sonozap.com, sciencelab.com, parker.com

Material Options Material applications Autoclave chambers
Must be able to withstand high temperatures and pressures Must be corrosion-resistant Environmental, inoculation, and reagent water chambers Need to be lightweight Reaction chamber Must be able to be sterilized Must be inert Criteria (order of importance) 1. Mass 2. Complexity (machineability) 3. Cost

Material Pros and Cons Pros Cons Polysulfone -Low density
-High yield strength -Easy to machine -Could not withstand contact with heating elements -Somewhat expensive 316 Stainless Steel -High strength -Very high melting temperature -Relatively inexpensive -High density Ultem 1000 Additional Options for Soil/Water Transportation and Mixing

Electrical Design Options
Pictures from spectrolab.com, fuelcellstore.com, dpie.com, weedinstrument.com

Power Supply Options Power supply requirements
Power supply must provide 30 W of power Must power the MiDAs instrument for duration of experiment (17 days) Criteria (order of importance) Cost Mass Volume

Power Supply Pros and Cons
Fuel Cell -Very high energy density -Safety and logistic issues -Switching out tanks -Expensive Sealed Lead Acid Battery -High energy density -Less complex -Very large and heavy -Requires a recharge system Lithium Ion Battery -High demand -Problems holding charge with age Dual Junction Solar Cells -Safe, relatively simple -Can be used to recharge batteries -Requires sunshine Additional Options for Data Acquisition and Pressure/Temperature Sensors

Feasibility and Risk Picture from

Project Risk Assessment
Subsystem Mitigation Factors Risk Factors Lots of Options Inexpensive Easy to Obtain Simple Easy to Machine Lack of Expertise Expensive Difficult Analysis Hard to Obtain High Power Use Thermal Control X Insulation Material Soil Handling Mixing Power Supply Data Acquisition Sensors Green Subsystems= Low Risk Yellow Subsystems = Medium Risk Red Subsystems= High Risk

Autoclave Feasibility Assumptions
Fluid inside is only water (high specific heat of water will give maximum boundary) Insulation radius = 10 cm of material (thermal conductance of k = W/m °C) Internal and external losses and safety margin = 2.4W (20% of heating/cooling capacity) Specific heat (Cp) for 316 steel = 452 J/kg K Specific heat (Cp) for water = 4230 J/kg K Heater uses 12 W per chamber Standard autoclave techniques implies 121°C, hold for 15 min Cool to 20°C, hold for 24 hours Repeat 3 times

Autoclave Feasibility Analysis
Time to heat from -10°C to 121°C = 3.9 hours Time to cool to 20°C = 117 min with active cooling Power: 3.9 amp hours to heat 0.04 amp hours to hold for 15 minutes 1.95 amp hours to cool 3.36 amp hours to hold for 24 hours Rconduction = = 79.8 C/W

Autoclave Solution and Verification
Sterilization chamber mock-ups will be made and tested with various heaters and insulation to verify that it is possible to achieve 121°C Verification: Temperature and pressure sensors will be used to verify that a sand/water solution can reach 121°C on 30 W of power

Autoclave Power Summary

Mixing Feasibility Analysis
Requirement: Soil and water must be mixed within the reaction chambers Reduces boundary layer so electrochemical sensors can read correctly Prevents soil sedimentation Problem: Difficult to find mixers small enough to fit in reaction chambers Flow pattern difficult to analyze without testing Unknown if ultrasonic mixers can be used at appropriate frequency Magnetic stirrers may affect electrochemical sensors

Mixing Solution and Verification
Mock-ups of reaction chambers will be prototyped and tested with various mixers Different soil granularities will be tested Various mixing regimes will be tested Continuous mixing Pulsed mixing Verification: Flow patterns and soil sedimentation will be visually analyzed to show that various types of mixing regimes and mixers provide adequate stirring

Project Plan Picture from

Organizational Chart

Schedule Through CDR

Schedule Past CDR Machining: Testing: Final Review – April 17, 2007
Assume one chamber machined per week Last Machining Day – March 16, 2007 Testing: Subsystem testing can begin as soon as each chamber is constructed Overall testing: March 16, 2007 – April 17, 2007 Final Review – April 17, 2007 ITLL Expo – April 28, 2007 Final Report – May 3, 2007

Conclusions Project is feasible Budget is one-quarter of funds
Mass is 34 kg, which is portable Initial calculations and research indicate that high risk subsystems (mixing and autoclaving) are challenging but possible Further analysis through prototyping will be performed before CDR System is capable of performing in specified environments System is capable of performing with 30 W of power Many options are available to meet each requirement This allows off-ramps in case some options are dismissed during design

Questions/Comments? Picture from

References Cengel, Yunus. Introduction to Thermodynamics and Heat Transfer. McGraw-Hill. University of Nevada, Reno. 1997 Gilmore, David. Spacecraft Thermal Control Handbook. Aerospace press. El Segundo, California. 2002

Appendix Table of Contents
System Architecture Options Chamber Geometries Verification Methods Power Model and Budgets Operational Environment Subsystem Options, Trade Studies, and Pros and Cons

Appendix A: System Parameter Estimates
Mass (g) Volume (mL) Cost Reaction Chamber 127 100 $11 Large Autoclave Chamber 4013.5 500 $125 Small Autoclave Chamber 250 $63 Soil Transport 88 $2.60 Motor 150 200 $20 Moving Sensor Package 254 $22 Environmental Sensors 10 50 $200

Assessment of System Design Alternatives
Quantitative Analysis of Options Mass (g) Volume (mL) Cost Shared Environment, Shared Sterilization 900 4444 $150 Separate Environment, Shared Sterilization 1200 4504 $1,350 Separate Environment, Separate Sterilization 1400 4612 $1,750 Shared Sterilization, Separate Environment 1300 4592 Mass, volume, and cost figures do not include components that all options need the same number of, such as a reagent water tank and mixers.

Option A Sterilization and testing occur in same chamber Requires:
1 large autoclave 2 moving sensor packages 2 motors 2 environmental sensors High complexity from moving sensor packages Mass: 1000 g Volume: 4842 mL Cost: $600

Option B Shared sterilization, separate environment Requires:
1 large autoclave 2 reaction chambers 2 soil transport tubes Mass: 900 g Volume: 4444 mL Cost: $150

Option C Shared sterilization, separate environment Requires:
1 large autoclave 2 reaction chambers 2 soil transport tubes 6 environmental sensors Mass: 1200 g Volume: 4504 mL Cost: $1350

Option D Separate sterilization, separate environment Requires:
2 small autoclaves 2 reaction chambers 3 soil transport tubes 8 environmental sensors Mass: 1400 g Volume: 4612 mL Cost: $1750

Option E Separate sterilization, shared environment Requires:
2 small autoclaves 2 reaction chambers 3 soil transport tubes 6 environmental sensors Mass: 1300 g Volume: 4592 mL Cost: $1350

Autoclave Chamber Geometry
Assumptions of a possible design: Chamber is made of 316 stainless steel 5 mL water added to chamber for use in autoclaving 15 mL space provided so sample is not tightly packed Chamber is a cylinder Dimensions: Total internal volume of chamber = 45 mL Internal diameter = 2.54 cm External diameter = 3.04 cm Wall thickness = 0.25 cm Length = 9.38 cm Mass = 0.19 km

Reaction Chamber Geometry
Assume: Chamber is made of Ultem 1000 Chamber wall thickness of 0.5 cm Inside chamber geometry is a cylinder 20 mL additional space for mixing (70 mL total volume) Dimensions: Walls: 0.5 cm thick Outside diameter = 3.95 cm Height = cm Mass = kg Drawings by Jake Freeman

Environmental Chamber Geometry
Assume: Chamber is a cube containing both reaction chambers Buffer around chambers is 3 cm with 2 cm between them Dimensions: Height: cm Depth: cm Width: cm Volume: cm3 Top View Side View

Reagent Water Chamber Geometry
Assume: Chamber is a cylinder Water expands upon freezing Dimensions: Height: 2.1 cm Radius: 3.0 cm Volume: 60 cm3 Side view

Verification Methods Requirement # Title Verification Method PDD 4.1
Reaction Chamber Volume I, D Verification will be through simple volume measurement. PDD 4.2 Reaction Chamber Temperature A, T Verification will be through thermal analysis of the reaction chamber geometry and test by means of simple temperature sensors. PDD 4.3 Reaction Chamber Pressure Verification will be through thermal analysis of the reaction chamber geometry and test by means of simple pressure sensors. PDD 4.4 Reaction Chamber Sensor Capability A, I Verification will be through analysis of the chamber geometry and by visual means. PDD 4.5 Reaction Chamber Mixing Capability Verification will be through analysis of the flow pattern generated during mixing and basic prototype inspection testing. PDD 4.6 Reaction Chamber Multi-Use Port PDD 4.7 Reaction Chamber Material A Verification will be through structural and thermal analysis of the reaction chambers. PDD 4.8 Geological Sample Volume T Verification will be through measuring soil before it is added to the autoclave chambers PDD 4.9 Inoculation Sample Volume Verification will be through measuring inoculation sample before it is added to the inoculation sample chamber PDD 4.10 Inoculation Sample Reception A, D Verification will be through analysis of soil transport and demonstration to show sample delivery.

Verification Methods PDD 4.11 Reaction Sample Handling A, T
Requirement # Title Verification Method PDD 4.11 Reaction Sample Handling A, T Verification will be through thermal analysis of the autoclave chambers and testing by means of temperature and pressure sensors. PDD 4.12 Inoculation Sample Handling Verification will be through thermal analysis and testing by means of temperature sensors. PDD 4.13 Reaction Sample Delivery A, D Verification will be through analysis of soil transport and demonstration to show sample delivery. PDD 4.14 Inoculation Sample Sterility Verification will be through analysis of soil transport and demonstration to show sample delivery. PDD 4.15 Reagent Water Containment Verification will be through thermal analysis and test by means of temperature sensors. PDD 4.16 Reagent Water Delivery PDD 4.17 Reagent Water Temperature Verification will be through thermal analysis and test by means of temperature sensors. PDD 4.18 Sensor Integration A, I Verification will be through analysis of the reaction chamber geometry and simple volume measurement. PDD 4.19 Sensor Data Collection Rate Verification will be through analysis and testing of the command software. PDD 4.20 Sensor Data Acquisition

Verification Methods Requirement # Title Verification Method PDD 4.21
Sensor Data Accessibility D Verification will be through demonstration of data transfer. PDD 4.22 MiDAs Status Warnings A, T Verification will be through analysis and testing of the command software. PDD 4.23 MiDAs Command PDD 4.24 Field Power Verification will be through analysis of the power supply and testing through standard electronics lab equipment. PDD 4.25 Laboratory Power Verification will be through a demonstration of the instrument with the external laboratory power supply. PDD 4.26 Nominal Power Consumption Verification will be through analysis of the power consumption of each component and testing. PDD 4.27 Peak Power Consumption Verification will be through analysis of the power consumption of each component and testing. PDD 4.28 Unit Disassembly Verification will be through a demonstration of the instrument disassembly. PDD 4.29 Operational Cycle Verification will be through a demonstration of a complete operational cycle. PDD 4.30 Operational Environment A Verification will be through thermal analysis of the surrounding environment.

Power Model

Mass Budget Autoclave (316 Steel) x 2 9 kg
Test/control/water chamber (Ultem1000) x 3 2.13 kg Inoculation chamber (Ultem1000) 0.19 kg Autoclave Insulation (Aerogel) 13.4 kg Test/control Insulation (Aerogel) 2.9 kg DAQ 0.285 kg Sensors 0.125 kg Extra (Ultem1000 Chassis) 6 kg Power supply 4 to 30 kg Total (excluding power supply) 34 kg

Cost Budget Heaters x 4 $160 Autoclave (316 Steel) x 2 $240
Test/control/water chamber (Ultem1000) x 3 $40 Inoculation chamber (Ultem1000) Included above Autoclave Insulation (Aerogel) $500 (min purchase) Test/control Insulation (Aerogel) DAQ $995 Sensors $345 Total $2280 Total Funds: $4000 from Senior Projects $4000 from BioServe Total: $8000

Operational Environment
Laboratory McMurdo Bay, Antarctica (summer) Atacama Valley, Chile (Altitude = 2000 m) Temperature (max) 30°C 2°C 38°C Temperature (min) 20°C -10°C -6°C Pressure (avg) 1 atm 0.802 atm

Thermal Control Design-To Requirements
Title Requirement Importance PDD 4.2 Reaction Chamber Temperature Each reaction chamber shall be controllable within a range of 4°C to 37°C with an accuracy of ±1°C. This environment is acceptable for the possible life to metabolize and reproduce. PDD 4.11 Reaction Sample Handling The reaction samples shall be sterilized in accordance with standard Autoclave techniques. This is the best method of sterilization for killing the known forms of life. PDD 4.15 Reagent Water Containment The sterile reagent water shall be completely contained in both solid and liquid form. This prevents the reagent water container from bursting if the water freezes. PDD 4.17 Reagent Water Temperature The reagent water shall be delivered to the reaction chambers at a temperature not to exceed 60°C. The electrochemical sensors can't withstand temperatures above 60°C. PDD 4.30 Operational Environment MiDAs shall be able to operate in environments ranging from Antarctica to Atacama Valley in Chile. These are the likely test sites for the MiDAs instrument.

Heating/Cooling Options
Heating applications Autoclave chambers: must reach 121°C and hold for 15 minutes Environmental chambers: must maintain temperatures from 4°C to 37°C for 14 days Cooling applications Autoclave chambers – must be cooled from 121°C to 20°C Environmental chambers – must maintain temperatures from 4°C to 37°C for 14 days Criteria 1. Volume 4. Complexity 2. Power consumption 5. Mass 3. Risk Cost

Heating Option Pros and Cons
Strip -Strong sheath -Difficult to find small sizes Tubular -Good at heating air -Custom length and resistance needed Tape or flexible -Cheap -Easy to custom-order -Kapton coating -Clamping system required -Best used for conduction heating Immersion -Direct heating for substance -Heating element may get in the way of mixer Cartridge -High watt density -Requires tight tolerances for placement Band -Small sizes don’t have high wattages

Cooling Option Pros and Cons
Passive -Does not require power -Simple -Geometry of chambers may limit effectiveness -Longest cooling time Heat Switch -Allows most sides of chamber to be insulated while still allowing cooling -Complex implementation -Difficult to find data Thermoelectric Cooler -Concentrated cooling power -Requires power

Heating Options Heating application Typical off the shelf example
Power of example Overall Size of example (inches) Weight of example (lbs) Price of example Strip Gases or solid surfaces Omega PT-512/120 2.5W at 12V 5.5 x 1 x 1.5 0.4 $30 Tubular Gases Omega TRI-1212/120 3.3W at 12V 0.246 O.D.x 12 long 0.2 $28 Tape or flexible Solid surfaces or possibly gases Minco HK5464R4.9L12A 29.39W at 12V 3 x 3 0.01 $33.80 Immersion Liquids Omega RI-100/120 2W at 12V Internal heating component = tube 1.5 long x O.D. 3 $115 Cartridge Solids Omega CSS-01235/120 0.7W at 12V 0.124 O.D. x 2 long 0.06 $26 Band Solids in cylindrical form Omega MBH A /120 4W at 12V 1.25 I.D. x 1.5 width 0.87 $32

Cooling Options Typical off the shelf example Power of example
Overall Size of example (inches) Weight of example (lbs) Price of example Passive Cooling NA $0 Heat Switch Starsys Research Diaphragm Thin Plate Switch May not be available at this time Thermoelectric Cooling Melcor CP L-1-W5 16 W 30 mm x 30 mm x 3.2 mm 0.024 $15.54

Fiber Board (Sindayno) -350
Insulation Options Density (kg/m^3) Cost K (W/m-K) Silica Aerogel 5-200 $325 for 50 g + $30 shipping TC- Ceramic Unknown 0.097 Fiber Board (Sindayno) -350 1900 0.63 Air 1.168 NA 0.025

Material Design-To Requirements
Title Requirement Importance PDD 4.7 Reaction Chamber Material Each reaction chamber shall be manufactured out of a list of materials provided by BioServe. This list includes, but is not yet limited to, Polysulfone, Pharmed, 316 stainless steel, and Ultem 1000. All of these materials are able to be autoclaved, have high resistance to corrosion, and are FDA approved for food service or medical use. PDD 4.11 Reaction Sample Handling The reaction samples shall be sterilized in accordance with standard Autoclave techniques. This is the best method of sterilization for killing the known forms of life.

Maximum Temperature (°C)
Material Options Density (g/cm3) Yield Strength (MPa) Maximum Temperature (°C) Cost per kg Machineability Polysulfone 1.24 74.9 $5.93 Very good 316 Stainless Steel 8.027 205 899 $2.32 Fair Ultem 1000 1.27 110 170 $3.84

Soil Handling Design-To Requirements
Title Requirement Importance PDD 4.8 Geological Sample Volume Each reaction chamber shall receive no less than 5 mL and no more than 25 mL of geological sample. 5 mL is the about the minimum amount of soil to obtain good results. 25 mL is still small enough amount to keep the experiment light and portable. PDD 4.9 Inoculation Sample Volume The test chamber shall receive a maximum of 1 mL of inoculation sample. The nonsterile inoculation sample is what could contain life. PDD 4.10 Inoculation Sample Reception The test chamber shall receive the inoculation sample through established aseptic techniques. The user needs to know that any detected life forms were already present in the soil, not transferred to the soil through the transportation method. PDD 4.13 Reaction Sample Delivery One pre-measured reaction sample shall be delivered to the test chamber and one pre-measured reaction sample shall be delivered to the control chamber. Both samples shall maintain sterility throughout delivery. Having equal amounts of soil in each reaction chamber helps maintain uniformity between the test and control. Once the soil is sterilized, it has to remain sterile so that no life forms are introduced. PDD 4.14 Inoculation Sample Sterility The inoculation sample shall be aseptically delivered to the test chamber. The inoculation sample can't pick up any living organisms from the MiDAs instrument. If life is detected, one needs to know that it was originally in the soil or the experiment is useless. PDD 4.16 Reagent Water Delivery The MiDAs shall aseptically deliver no more than 50 mL (within ± 5% accuracy) of sterile reagent water to each reaction chamber. The delivery must be aseptic, so that no living organisms are transferred to the reagent water. PDD 4.28 Unit Disassembly MiDAs shall be able to be taken apart so that it may be sterilized and reassembled for multiple Earth tests. The instrument needs to be reusable.

Soil/Water Transportation Options
Soil and water transportation includes pumps, tubing, and valves Soil/water handling applications Reagent water transferred to sterilization and inoculation chambers to flush soil Soil and water mixture transferred from sterilization and inoculation chambers to reaction chambers Criteria 1. Complexity (autonomy)

Soil/Water Transportation Pros and Cons
Push/Pull Solenoids -Simple Low cost -High reliability Small -Not variable Electromagnets -Simple Med cost -High reliability Small -High power usage Motor -Compatibility Low cost -Small -Complexity -Low reliability Pressure Sealing -High reliability -Two way -Complex setup Magnetic Sealing -Less parts -Low reliability Complex setup -One way -May have interference with sensors Gates Sealing

Soil Transportation Options
Gate Options Voltage Power Complexity Reliability Size Push/Pull Solenoids 3VDC 3W low high d = 25.5mm h = 28.9mm Electromagnets 12VDC ? d = 35mm h=~45mm Motor System Motor 58 RPM d =6.3 mm Belt System N/A med custom Sealing Options for Autoclave Pressure Sealing Pressure Plug Push/Pull Solenoid High Torque Motor TBD d = 127mm h = 127mm Magnetic Sealing very large High Compression Spring

Mixing Design-To Requirements
Title Requirement Importance PDD 4.5 Reaction Chamber Mixing Capability Each reaction chamber shall have mixing capability such that each geological sample is evenly distributed within the fluid while movement is present at each sensor location. The fluid must be mixed so that the sensor readings are as accurate as possible. The fluid must also move at each sensor so that the boundary layer around the sensors is broken down, which is necessary to get a reading. PDD 4.28 Unit Disassembly MiDAs shall be able to be taken apart so that it may be sterilized and reassembled for multiple Earth tests. The instrument needs to be reusable.

Mixing Options Mixing applications
Soil in reaction chambers must be stirred Electrochemical sensors need fluid movement to function Prevents sedimentation to soil Criteria (order of importance) 1. Volume 2. Power usage 3. Risk 4. Cost

Mixing Option Pros and Cons
Ultrasonic -BioServe may provide -Does not disrupt ISE’s -Ruptures cell membranes above 18 kHz -Expensive -Lack of prior experience Magnetic -No known machining required -Does not require probe through top or bottom of reaction chambers -ISE interference pending test -Magnetic Martian soil Mechanical -Known flow-pattern -Common use / more experience -Soil could clog mechanism -Most COTS mixers are too large

Probe tip: 1/8" diam x 2" long Ti alloy
Mixing Options Volume Cost Power Ultrasonics PCB: 5" x 2 3/4" x 1" $1295* variable Probe: 0.850" diam, 4 1/2" long Probe tip: 1/8" diam x 2" long Ti alloy Magnetic 4.8” x 4.8” x 1.8” Unknown Mechanical 0.8 mm diameter impeller Unknown

Power Supply Design-To Requirements
Title Requirement Importance PDD 4.24 Field Power MiDAs shall provide its own power (between 10 W and 30 W) in a field setting. PDD 4.25 Laboratory Power MiDAs shall be capable of receiving between 10 W and 30 W from an external power supply in a laboratory setting. The instrument needs to be capable of running in a lab, as well as the field. PDD 4.26 Nominal Power Consumption Nominal power consumption shall not exceed 30 W. This is based on estimates of the Mars astrobiology rover PDD 4.27 Peak Power Consumption Peak power consumption shall not exceed 30 W for more than 30 seconds. PDD 4.29 Operational Cycle One operational testing cycle shall be 14 standard Earth days, not including power-up, sterilization, and power-down. This is the time given for the potential life to reproduce and metabolize.

Power Supply Options Mass (kg) Volume (cm3) Cost Power Provided
Time for Delivery Fuel Cell 1.133 637 $1769 12V 3-4 Weeks Sealed Lead Acid Battery 30 10577 $165 40 hrs, 12 V 2-3 Weeks Lithium Ion Battery 8 4800 $40 30 12V Dual Junction Solar Cells 0.118 kg (does not include backing) Area = 30 cm2 $940 (to charge) 30 12 V 2 Weeks

Data Acquisition Design-To Requirements
Title Requirement Importance PDD 4.4 Reaction Chamber Sensor Capability Each reaction chamber shall be capable of supporting no fewer than 6 and no more than 18 electrochemical sensors. This is the number of electrochemical sensors that will be provided by the customer. PDD 4.19 Sensor Data Collection Rate The electrochemical sensors shall have a data collection rate of 1 measurement per minute per sensor. Since the experiment takes place over 14 days, a reading each minute from each sensor is sufficient to characterize the experiment results. PDD 4.20 Sensor Data Acquisition All data taken through the sensors shall be collected and stored for analysis. The data will be analyzed after the experiment is completed. PDD 4.21 Sensor Data Accessibility The scientific and engineering status data shall be accessible to users throughout the experiment. The customer would like to be able to look at the status of the experiment while it is in progress. PDD 4.22 MiDAs Status Warnings MiDAs shall provide caution, warning, and instrument status to external ground support equipment. This is necessary to be able to observe the status of the instrument, as well as detect errors. PDD 4.23 MiDAs Command MiDAs shall receive commands from external ground support equipment. The duration of the experiment is such that it is not reasonable to have the user initiate each step of the process. PDD 4.29 Operational Cycle One operational testing cycle shall be 14 standard Earth days, not including power-up, sterilization, and power-down. This is the time given for the potential life to reproduce and metabolize.

Data Acquisition Options
Data acquisition applications: Must be able to give commands to sensors, heaters, and soil transport Must be able to store data with a collection rate of one sample per sensor per minute Criteria: Power usage Cost

Data Acquisition Options
DAQ Cards model power price Weight Width Length Height Resolution Memory Time LabJack UE9 5 V or by USB cable $429 --- 75mm 185mm 30mm 16 bit 2 week shipping LabJack U3 by USB cable $99 115mm 12 bit Embedded CPU with DAQ Athena 10 W $825 150 g 4.175" 4.45" 128 MB Poseidon 3.5 W $995 4.528" 6.496" 256 MB Elektra 5.5 W $750 108 g 3.55" 3.775" Hercules 12 W $500 285 g 8" 5.75"

Data Acquisition Pros and Cons
Data Acquisition Card -Self powered (draws power from computer) -Requires additional hardware Embedded CPU w/ Data Acquisition -Embedded system -Can provided variety of data transfer options -Can be used to store data until testing complete -Can provide accessibility to autonomous control -Requires additional power consumption -Expensive

Pressure and Temperature Sensor Options
Pressure and temperature sensor applications: One of each sensor in the sterilization chambers capable of withstanding high temperature One of each sensor in the each reaction chamber One temperature sensor in the reagent water chamber Criteria: Cost Power usage Temperature range

Temperature Sensor Pros and Cons
Thermocouples -Variety of types and configurations -Low cost, wide availability -Reliable -Self-powered -Can handle autoclave temperatures -Requires a cold junction compensator for calibration -Sensor accuracy can reach 1°C at temperatures between 10°C and 40°C Thermistors -Better accuracy than thermocouples and RTDs -Loss of linearity -Requires shielding from high temperatures -Requires current Resistance Temperature Detectors (RTD) -High accuracy -Excellent stability and reusability -Can be immune to electrical noise -Requires current to take measurements

Temperature Sensor Options
Thermocouples Volume Model Cost Weight Diameter Length Temp Range Operation Range Accuracy (1-40 °C) Time 5SRTC-TT (mini connector) $ (5 pack) --- 0.51mm 1m T ±1 °C 2 day shipping available TJ36 (autoclave probe) $92 1.6mm JKTE Thermistor 44005 $15 2.8mm 60mm -80 to 250 °C RTD Height Width SA1-RTD $50 25mm 2m 19mm -73 to 260 °C ±0.5 °C CJC MCJ-T (battery included) $99 57 g 13mm 75mm 10-45 °C CJ-T (battery included) $170 75 g 12mm 49mm 10-50 °C

Pressure Sensor Pros and Cons
Gauge -Widely available -Relatively cheap -Measures pressure relative to standard atmosphere Absolute -Measures pressure relative to vacuum -Requires additional sensors to measure local conditions Differential -Measures difference between two locations -Slightly more expensive than gauge and absolute

Pressure Sensor Options
Pressure Sensors Volume Model Cost Weight Height Length Width Temp Range Power Accuracy *** Time PX138 * $85 --- 26.2mm 28.1mm 27.9mm 0 to 50 °C 8VDC 0.1% 0.5% 1 week shipping PX139 * 5VDC @2 mA PX140 * $120 -18 to 63 °C 0.75 % 0.15% Diameter PX209 ** $195 12mm 57.9mm -54 to 121 °C 24VDC @ 15 mA 0.25% 0.25%

Microbial Detection Arrays

Similar presentations

Presentation on theme: "Microbial Detection Arrays"— Presentation transcript:

Similar presentations

About project

Feedback

Log in

Auth with social network:

Microbial Detection Arrays

Similar presentations

Presentation on theme: "Microbial Detection Arrays"— Presentation transcript:

Similar presentations

About project

Feedback