P18082: Electrical Bioreactor
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Systems Design

Table of Contents

Team Vision for System-Level Design Phase

  1. Define and finalize total list of functions and subfunctions that need to be delivered
  2. Determine best design solution available by conducting benchmarking through research articles
  3. Outline concept developments for the electrical bioreactor that can pair with benchmark results and contribute to additional design ideas
  4. Set realistic standards and goals to ensure our team can deliver for our customer

Functional Decomposition

Functional Decomposition

Functional Decomposition

The purpose of Functional Decomposition is to define a list of functions and subfunctions of a project which need to be delivered by the project’s final design stage. This will allow teams to establish the concepts needed in order to deliver project objectives. The power of language is very important when constructing functional decompositions: something our team learned about while developing our Functional Decomposition chart for the electrical bioreactor. For example, the bioreactor itself does not need to include a microscope in the final design since it is not used to periodically monitor cell growth. However, the bioreactor does have to provide the ability for cell growth to be viewed and monitored by a microscope. Understanding this simple difference in language was instrumental in our team’s comprehension of the purpose and use of Functional Decomposition in the Systems Design process.

Benchmarking

P18082 Benchmark Research Prototypes and Ideas

P18082 Benchmark Research Prototypes and Ideas

P18082 Benchmark Analysis

P18082 Benchmark Analysis

Link to live P18082 Benchmarking

Morphological Chart

FIG3. P18082 Morphological Chart

FIG3. P18082 Morphological Chart

The figure above shows the generated concepts for each functions’ subfunction above. The (1) bioreactor sterilization will be performed via (1.1) dry heat, (1.2) Ethanol Solvent, (1.3) IPA Solvent, or (1.4) Autoclave; with (2) viewability of the cell culture through (2.1) EVOS microscope, (2.2) Leica microscope, (2.3) generic microscope, or (2.4) all microscopes. The bioreactor will be (3) portable as a (3.1) disassembled unit or (3.2) one unit system; with the (4) culture system designed as a (4.1) salt bridge chamber, (4.2) T-flask, (4.3) petri dish, (4.4) self made culture system, (4.5) or outfitted well plate; with an (5) air and gas exchange of a (5.1) T-flask ventilated cap, (5.2) drilled holes in lid, (5.3) incubator fan, or having the (5.4) incubator already provide exchange. The (6) power supply will be provided by (6.1) wall power, (6.2) wall power and USB power, (6.3) battery, (6.4) wall power with battery backup, or (6.5) USB with battery backup; with a (7) user interface of either (7.1) LabVIEW, (7.2) Adruino, or (7.3) Physical Controls; using (8) system controls offered through (8.1) LabVIEW, (8.2) Adruino, (8.3) Raspberry Pi. The (9) bioreactor circuit connections will then be attached through (9.1) hardwiring, (9.2) connectors, (9.3) electrical/mechanical contact connection, or (9.4) induction.

Concept Development

Function P18082Subfunction Team Votes
1. Bioreactor Sterilization
  • All votes were to choose Ethanol Solvent (1.2) for bioreactor sterilization since method is the most effective and readily available option in the lab
    • IPA Solvent (1.3) is similar to Ethanol Solvent, but is not as readily available in the lab
    • Dry heat (1.1) is not preferred because method is expensive and has the potential to be dangerous sterilization method
    • Autoclave (1.4) is currently unavailable in the lab and would increase assembly time
2. View-ability of Cell Culture
  • All votes were to have bioreactor be compatible with the EVOS and Leica and generic microscopes (2.4) which are all available in the lab: this subfunction is customer requirement and feasible to deliver upon
3. Portability
  • All votes were to have a bioreactor that can be disassembled (3.1) which allows for more feasible portable unit system: less complex and smaller size
    • A one unit system (3.2) is harder to transport since the bioreactor will be heavier, more valuable, and larger in design
4. Culture System
  • Two team members voted for T-flasks (4.2) due to addition their mechanical convenience as well as their biological convenience: T-flasks have angled sides at one end which would aid in the application of an incredibly simple/effective container securing mechanism
  • Two team members voted for outfitted 6-well plate (4.3) since multiple cultures can be conducted and altered simultaneously
  • One team member voted for a custom design culture (4.4) to achieve both mechanical convenience and preferred biological convenience of conducting multiple trials, was not selected for extended work and potential trial and errors
    • Salt bridges (4.1) provide too much variability in trials which results in low reliability of experiments, culture system would have a shorter life span requiring frequent replacement
    • Petri dishes (4.3) would limit mechanical implementations options which further limits other desired subfunctions
5. Air and Gas Exchange
  • Three team members voted for ventilated T-flask cap (5.1) due to its ability to allow for sufficient gas exchange between the incubator conditions and cell culture: ventilated T-flask cap is defaulted as subfunction for those voting for T-flask and custom design cell culture
  • Two team members voted for no ventilation (5.4) because the design and function of the outfitted 6-well plate and incubator defaults this subfunction due to current sufficient ventilation
6. Power Supply
  • Three team members voted for wall power and USB (6.2) because this option is readily available in the lab
  • Two team members voted for USB and battery backup (6.5) because while the USB provides power from either the wall or computer, the battery ensures power if there is an outage or error in USB connection
    • Wall power (6.1), battery (6.3), and wall power and battery backup (6.4), provide a limited source of power and would have to be replaced periodically
7. User Interface
  • Four team members voted for LabVIEW (7.1) because students interacting with the bioreactor are most familiar with system and LabVIEW is a reliable software program
  • One team member voted for physical controls (7.3) because it would elevate the usability of bioreactor and would be appealing to students who do not want to interact with software coding
    • Students interacting with the bioreactor are not familiar with Arduino (7.2) which introduces complexity
8. Systems Control
  • All team members voted for Adruino (8.2) because it can be internal to the system and separate from the user interface: applies as a physical hardware control system than part of a software
    • LabView (8.1) has to be an external program that would be continuously running and has the potential to be altered if controls are not locked
    • Raspberry Pi (8.3) requires more student experience with other interfaces but cost between other subfunctions is equivalent
9. Bioreactor Circuit Connection
  • All team members voted for Mechanical/Electrical contact connection (9.3) because it is the easiest and most reliable form of connection long term
    • Hardwire connection (9.1) has the potential to become confusing with multiple running wires and disconnecting unit system would not be as efficient
    • Students are less familiar with induction (9.4) and is complex implementation method
    • Connection with connectors (9.2) have the potential to wear and would require replacement, subfunction also has more design restraints
P18082 Subfunction Team Voting Schematic

P18082 Subfunction Team Voting Schematic

FIG3. P18082 Subfunction Team Voting Selection

FIG3. P18082 Subfunction Team Voting Selection

Feasibility: Prototyping, Analysis, Simulation

Bioreactor Sterilization: Ethanol

Ethanol is already widely used in Dr. Bailey’s lab, is known to be safe for these kinds of experiments, is readily available, and cheap.

Portability: Disassembly

Being able to remove the container from the electrical system will make it easier to clean, and maintain microscope viewability without much design work.

Gas Exchange: Ventilated T-cap for 25ml T-Flask or Ventilation not Needed for Outfitted 6-Well Plate

The outfitted 6-well plate already has gas exchange built into its design. The T-Flasks have the option of a vented cap.

Culture System: 25ml T-Flask and Outfitted 6-Well Plate

This flask is commonly used by Dr. Bailey’s students, so they will be familiar with it. Due to it already being used for growing cultures we know that the materials shouldn’t be toxic to the culture, and that it is relatively easy to clean. Also, these are very inexpensive. A 6 well plate would be better given the smaller culture growth area. This should give us a better chance of the culture surviving the full 3 weeks. Due to both of these options having potential, but very little in-the-way-of research findings to point to one over the other, we are moving forward with prototyping both, and comparing the results.

Power Supply: USB power; ability to be powered by computer or wall

USB power solves two problems in one. The same cable can be used to connect to the computer, and also be used for power. The computer usb port can supply power, but if the computer is normally off, you can plug the usb cable into a wall charger as well. This is a very effective, yet cost effective solution which is simple to implement. The addition of a battery backup will allow the culture to remain stimulated for a period of time during a power outage. We looked into using a battery as the only source of power, but the amount of energy needed for 3 week incubation periods would require a large expensive battery. However, another option considered was since the culture has to have media exchanged every ~3-4 days anyway, why not have rechargeable batteries that could last 5 days (much smaller and less expensive). While one battery is being used, another battery could be charging. The downside to this solution is that it would require the students to remember to swap out the batteries every time they exchange media. Due to the lack of a battery backup customer requirement, we are moving forward with just USB power, however might consider a battery backup in the future as a product improvement.

P18082 Power Supply Venn Diagram

P18082 Power Supply Venn Diagram

P18082 Battery Analysis

P18082 Battery Analysis

P18082 Power Supply Analysis

P18082 Power Supply Analysis

Circuit Connections: Contact Connection

If the electrodes are hardwired to the circuit, it would be difficult/impossible to remove the container from the system. This would make cleaning and viewing under the microscope quite difficult. If the electrodes are connected using some variant of plug (i.e. banana clip), then the students would have to disconnect and reconnect the leads every time the container is removed or put back into the system. This added complexity could lead to increased risk of electric shock, forgetting to connect, or damage to the system by forgetting to disconnect before attempting to remove the container. For these reasons, we believe it best to opt for a Contact Connection in which simply inserting the container into a port on the system will create a connection between the electrodes and the rest of the circuit. This can be done in such a way that the students won’t even have to think about it, and also their hands won’t come close to the connections, thus all but eliminating the risk of electric shock.

User Interface: Purely Software using LabView

During the interview process, Dr. Bailey made it clear that her students are used to using LabView interfaces, and prefer to stick with what they already know when it comes technology. Given that LabView is free for us to use, and that it can easily interface with many different micro-controllers, LabView seems like it will provide us with the functionality, flexibility, and customer ease-of-use which this project calls for. While additional physical controls could add utility while still being intuitive, the additional engineering resource cost needed to develop the physical controls seems to outway the potential benefits. Though if we end up with excess time, the addition of some physical controls should be revisited.

System Control: Micro-Controller, specifically Arduino

While the circuit could be hardwired and offer a few different settings via physical controls, we believe a micro-controller will be much better suited to provide the user with the functions and adjustability that Dr. Bailey has specified. While there are many micro-controllers available on the market, our team has the most experience with Arduino. Given that Arduinos are inexpensive, low power, and capable enough to run our circuit, it seems a perfect fit for this project

Concept Selection

P18082 Concept Generation Overview
Functions Concepts
1 2 3 4
Bioreactor Ethanol Ethanol Ethanol Ethanol
Viewability of Cell Culture All Microscopes All Microscopes All Microscopes All Microscopes
Portability Disassembled Unit Disassembled Unit Disassembled Unit Disassembled Unit
Culture System T-flask T-flask Outfitted 6-Well Plate Outfitted 6-Well Plate
Air and Gas Exchange T-flask Ventilated Cap T-flask Ventilated Cap Incubator Provided Exchange Incubator Provides Exchange
Power Supply Wall Power and USB Wall Power and USB Wall Power and USB Wall Power and USB
User Interface LabVIEW Physical Controls LabVIEW Physical Controls
Power Supply Wall Power and USB Wall Power and USB Wall Power and USB Wall Power and USB
Systems Control Arduino Arduino Arduino Arduino
Bioreactor Circuit Connection Electrical/Mechanical Contact Connection Electrical/Mechanical Contact Connection Electrical/Mechanical Contact Connection Electrical/Mechanical Contact Connection
P18082 Concept Generations Focal Points
Functions Concepts
1 2 3 4
Bioreactor Ethanol Ethanol Ethanol Ethanol
Viewability of Cell Culture All Microscopes All Microscopes All Microscopes All Microscopes
Portability Disassembled Unit Disassembled Unit Disassembled Unit Disassembled Unit
Culture System T-flask T-flask Outfitted 6-Well Plate Outfitted 6-Well Plate
Air and Gas Exchange T-flask Ventilated Cap T-flask Ventilated Cap Incubator Provided Exchange Incubator Provides Exchange
Power Supply Wall Power and USB Wall Power and USB Wall Power and USB Wall Power and USB
User Interface LabVIEW Physical Controls LabVIEW Physical Controls
Power Supply Wall Power and USB Wall Power and USB Wall Power and USB Wall Power and USB
Systems Control Arduino Arduino Arduino Arduino
Bioreactor Circuit Connection Electrical/Mechanical Contact Connection Electrical/Mechanical Contact Connection Electrical/Mechanical Contact Connection Electrical/Mechanical Contact Connection

Selection Criteria Description

  1. Accessibility: Refers to the ease with which an individual may access the cell culture.
  2. Assembly Time: Refers to the assembly required for setting up the system in order to run an experiment.
  3. Cleaning Time: Refers to the time that is required for cleaning the system after projects/experiments are completed (this criterion also includes the time required for disassembly).
  4. Cost: Refers to the cost of building and developing the initial prototype and any other additional systems that may be required.
  5. Durability: Refers to the overall hardiness of the system (i.e. whether the device will be able to survive handling by multiple individuals over the course of, at least, 3 years).
  6. Ease of Use of Control System: Refers primarily to the user interface, but also includes the simplicity of the system and whether the design is overly complicated.
  7. Ease of Use of Cell Culture: Refers primarily to the the ease of reaching the cell culture within the culture system (this includes changing media, initial seeding of cells, etc.).
  8. Handling: Refers to its likeliness to create issues due to size and space consumption.
  9. Manufacturing Time of User Interface: Refers to the time, and effort, that would be required to build the prototype and control systems (this is closely related with cost).
  10. Manufacturing Time of Cell Culture System: Refers to the time, and effort, that would be required to grow and nurture the culture system (this is closely related with cost).
  11. Power Life: Refers to the lifespan of our power source (especially relevant for a design that includes batteries).
  12. Safety: Refers to the characteristics of the system that could cause potential harm to an operator.
  13. Sterilization Time: Refers to the time required for sterilizing the culture system when work with the culture is required.
Pugh Analysis 1
Concept Design 1 2 3 4
Accessibility Datum 0 1 1
Assembly Time 1 0 1
Cleaning Time 0 1 1
Cost -1 0 -1
Durability -1 0 -1
Ease of Use – Cell Culture 0 1 1
Ease of Use – Systems Control 1 0 1
Portability 0 0 0
Manufacturing Time – Cell Culture 0 -1 -1
Manufacturing Time – User Interface -1 0 -1
Sterilization Time 0 1 -1
Safety -1 0 -1
Total -2 3 1
Pugh Analysis 2
Concept Design 3 1 2 4
Accessibility Datum -1 -1 0
Assembly Time 0 -1 1
Cleaning Time -1 -1 0
Cost 0 -1 -1
Durability 0 -1 -1
Ease of Use – Cell Culture -1 -1 0
Ease of Use – Systems Control 0 1 1
Portability 0 0 0
Manufacturing Time – Cell Culture 1 1 0
Manufacturing Time – User Interface 0 -1 -1
Sterilization Time -1 -1 0
Safety 0 -1 -1
Total -3 -5 2
P18082 Concept Selection

P18082 Concept Selection

The above concept selection outlines the set up between the culture system and wiring of the electrical bioreactor. The bioreactor will then be placed on a shelf in the incubator where the power supply and user interface will be located outside of the incubator. Wires connecting the two units will be run outside the incubator.

Systems Architecture

P18082 Systems Architecture

P18082 Systems Architecture

Risk Assessment

P18082 Risk Assesment

P18082 Risk Assesment

Link to live P180821 Risk Assessment

Plans for Next Phase

Software:
We will research how to control the Arduino micro controller through the LabView software. Once this is figured out, basic programs will be made in order to test the electrical design. (For now, the software is free and the Arduino is free for testing.)

Electrical:

Set up tests with media and various electrodes. Record the voltage, current, and resistance in an effort to understand how these may change over time. This will be an iterative process so as to develop a large enough analysis that positive conclusions can be made. This analysis will be crucial in making sure our electrical circuit design will meet the needs of the bioreactor.

Mechanical:

Solutions for mechanically securing the container into the system body will be drafted, modeled, and tested for viability. Also, the rough geometry of the body will be explored, helping to get an understanding of how much material we will need, and thus making a material cost analysis possible.

Bio-Medical:

Figuring out what cell types we will be moving forward with. This will help with the Electrical system preliminary design. Given that the biological part of this project may be the most expensive part, the cost analysis of the bio-materials is crucial. Create test plans which will be used later for iterating the design.

Project:

Continue to assess potential risks. Also, demonstrate that our testing methodologies will satisfy all of the Engineering Requirements.

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