Week 13: Mid Term Review

Compact Photobioreactor for Spirulina Cultivation

Assignment Description

For Week 13, I worked on the planning, organization, and management of my Final Project: a compact modular photobioreactor for spirulina cultivation.

The main objective of this week was to organize the complete workflow of the project, establish priorities, identify risks, define work modules, and generate a realistic schedule considering the remaining time until the final Fab Academy presentation.

This week allowed me to:

• Define the general architecture of the system.
• Organize the fabrication stages.
• Establish priorities according to time and resources.
• Identify dependencies between modules.
• Plan iterative prototypes.
• Integrate different digital fabrication processes.
• Evaluate technical risks and limitations.

1) General Project Description

The project consists of developing a compact modular photobioreactor for spirulina cultivation using digital fabrication processes, electronics, and embedded systems.

Spirulina is a microalga with high nutritional value due to its protein, vitamin, and antioxidant content. However, many existing cultivation systems are expensive, bulky, or difficult to monitor and automate at a small scale.

This project seeks to solve the need for a compact, modular, and low-cost system that allows spirulina cultivation using accessible digital fabrication technologies.

The system will integrate:

• a transparent thermoformed chamber,
• LED lighting,
• controlled aeration,
• environmental monitoring using sensors,
• and electronic control through ESP32.

In addition, the project seeks to demonstrate how multiple digital fabrication processes can be integrated into a single functional system oriented toward biotechnological applications.

2) Project Management Table

Component / Module	Function	Integrated Digital Fabrication	Identified Risk	Mitigation Strategy
Thermoformed acrylic cylinder	Main chamber for spirulina cultivation	CAD design in Fusion 360 + laser mold + thermoforming	Acrylic deformation or fracture	Progressive temperature tests and reinforced mold
Thermoforming mold	Maintains cylindrical geometry during bending	Laser cutting + parametric design	Loss of circularity	Structural reinforcement with ribs and aluminum
Structural base	Reactor support and electronic compartment	3D printing	Deformation due to water weight	Increase thicknesses and internal ribs
Upper technical cover	Organization of sensors and wiring	3D printing	Leaks or poor cable distribution	Removable modular design
Aeration system	Oxygenation and mixing of the culture	CAD design + 3D printing	Uneven bubble distribution	Circular system with double air inlet
Diffuser ring	Uniform bubble generation	3D printing	Buoyancy and air leaks	Incorporation of weight and sealing with silicone
LED system	Lighting for spirulina growth	CAD design + 3D printing	Overheating	Thermal separation and ventilation
ESP32	Control and monitoring of the system	Embedded programming	Communication or power failure	Modular design and individual tests
Temperature sensor	Thermal monitoring of the culture	Integrated electronics	Unstable readings	Calibration and sensor insulation
pH sensor	Chemical monitoring of the medium	Integrated electronics	Decalibration	Periodic calibration
TDS sensor	Monitoring the concentration of the medium	Integrated electronics	Incorrect readings due to bubbles	Strategic location and data filtering
IoT monitoring system	Notification and data visualization	Programming + ESP32	Lack of connectivity	Independent local system
Cable and hose management	Internal organization of the system	Parametric design + 3D printing	Disorder or interference	Central technical column
General integration	Union of all systems	Multidisciplinary digital fabrication	Delays due to complexity	Prioritization of the functional MVP

3) General Schedule

Gantt-type Schedule

Activity	S13	S14	S15	S16	S17	S18	S19	S20
Research and conceptualization	███	█
Initial CAD design	███	███	█
Modular reactor design	███	███	█
Thermoforming mold design	███	███
Acrylic dimension calculation	███	███
Mold fabrication		███	█
Thermoforming tests		█	███	█
Cylinder fabrication			███	█
Aeration system design		███	███
Diffuser ring printing			███	█
Structural base design		█	███	███
Electronic integration			█	███	█
Sensor integration			█	███	█
ESP32 programming			█	███	█
Final assembly					███	███
Final tests and debugging						█	███
Final documentation	█	█			███	███
Final presentation								███

5) Reflections

• Week 13 allowed me to understand that a successful project does not depend only on the fabrication of components or technological development, but also on proper planning and management of each stage of the process. Before starting the fabrication of the photobioreactor, it was necessary to define clear objectives, establish priorities, and organize the activities according to the available resources and time.
• During this week, I understood the importance of dividing a complex project into independent modules. This strategy facilitates testing, reduces risks, and allows progress to be made gradually, validating each system before integrating it into the final assembly. Thanks to this, I was able to structure the reactor development into subsystems such as the cultivation chamber, aeration, lighting, electronics, and monitoring.
• Project management also allowed me to identify technical risks from early stages, such as possible leaks, acrylic deformation, aeration problems, or time limitations for fabrication. Anticipating these problems helped me propose mitigation strategies before starting the construction of the system.
• Another important aspect was understanding that, in an innovation project, it is essential to maintain flexibility to adapt the design to the resources that are actually available. During the process, it was necessary to rethink some construction solutions and prioritize the essential functionalities to guarantee the viability of the prototype within the established deadline.

6) Conclusions

• Project management made it possible to establish a clear roadmap for the development of the spirulina photobioreactor, defining objectives, activities, resources, and the time needed to achieve a functional solution.
• Modular planning facilitated the organization of the work, allowing each system component to be developed and validated independently, reducing risks and optimizing the fabrication process.
• The early identification of technical risks and time limitations made it possible to prioritize critical project activities, focusing efforts on the development of a minimum viable product capable of demonstrating the main operation of the system.
• The integration of CAD design, digital fabrication, electronics, and programming tools demonstrates the potential of digital fabrication laboratories to develop innovative biotechnological solutions through accessible and replicable processes.
• Week 13 was fundamental in transforming an initial idea into a structured project, allowing a realistic development strategy aligned with the objectives and timing of Fab Academy to be defined.
• The project management process carried out during this stage will serve as a basis for future improvements to the system, including harvesting automation, remote monitoring, intelligent control of cultivation variables, and scaling of the photobioreactor.