SpiruSense is an intelligent photobioreactor designed for the cultivation and monitoring of Limnospira platensis (spirulina). The system will measure critical cultivation variables such as temperature, pH, total dissolved solids (TDS), and light intensity in real time. In addition, the data can be visualized locally through an LCD screen and remotely through an IoT platform connected to Firebase. It will also allow lighting and aeration to be controlled from a web application, improving growth conditions and facilitating cultivation monitoring.
Img. 1: Diagram of how the photobioreactor structure will be.
There are several projects and developments related to photobioreactors for the cultivation of microalgae and spirulina. During the research phase, both academic references and projects developed within the Fab Academy community were reviewed.
One reference was the “Microalgae Bio-Photoreactor” project developed in Fab Academy, focused on building a system for the controlled cultivation of microalgae through lighting and aeration. This project helped me understand aspects related to the design of transparent reactors, circulation of the culture medium, and the importance of avoiding dead zones inside the system.
Commercial developments of automated photobioreactors used for microalgae research and production were also reviewed. These systems incorporate sensors, parameter monitoring, and control systems to optimize crop growth. They demonstrate the importance of integrating real-time monitoring, environmental control, and data logging to improve productivity.
Likewise, initiatives such as Ecotrons and AlgaGrower were analyzed. These are oriented toward automated microalgae cultivation and the development of experimental platforms for biotechnological research. They served as inspiration for the integration of sensors, connectivity, and remote monitoring within a compact system.
SpiruSense seeks to develop an accessible alternative based on digital fabrication, integrating CAD design, 3D printing, thermoforming, custom electronics, environmental sensors, WiFi communication, and cloud monitoring through Firebase. The objective is to provide a low-cost tool for educational institutions, Fab Labs, and small producers interested in cultivating Limnospira platensis (spirulina).
Img. 2: Commercial photobioreactor.
Img. 3: Fab Academy project used as a reference.
The development of SpiruSense will be supported by various technical, scientific, and reference sources that will help validate both the mechanical design and the electronic and biological integration of the system.
Img. 4: Sensors used.
Img. 5: Research on photobioreactors.
The following elements will be designed and fabricated:
Img. 6: Fusion design of the photobioreactor.
| Material or Component | Quantity |
|---|---|
| XIAO ESP32-C3 | 1 |
| DS18B20 sensor | 1 |
| TDS sensor | 1 |
| pH E201-C BNC electrode | 1 |
| BH1750 sensor | 1 |
| I2C LCD screen | 1 |
| Air pump | 1 |
| 1.5 m LED strip | 1 |
| FR1 PCB | 1 |
| PLA filament | 2 kg |
| Transparent acrylic | 1/4 sheet |
| Silicone hoses | 2 m / several |
| SMD electronic components | Several |
The materials and components will be obtained from:
Img. 7: Air pump used.
| Component | Quantity | Total Cost (S/.) | Total Cost (USD) | Use in the Project |
|---|---|---|---|---|
| XIAO ESP32-C3 | 1 | 40.00 | 11.11 | Main microcontroller |
| DS18B20 sensor | 1 | 5.50 | 1.53 | Temperature measurement |
| TDS sensor | 1 | 75.00 | 20.83 | Dissolved solids measurement |
| pH E201-C BNC sensor | 1 | 65.00 | 18.06 | pH measurement |
| BH1750 sensor | 1 | 10.00 | 2.78 | Light intensity measurement |
| I2C LCD screen | 1 | 25.00 | 6.94 | Local visualization |
| Air pump | 2 | 36.00 | 10.00 | Culture aeration |
| Relay module | 2 | 20.00 | 5.56 | Lighting and aeration control |
| LED strip | 1 | 5.00 | 1.39 | Culture lighting |
| 12V power supply | 1 | 60.00 | 16.67 | Main power supply |
| LM2596 Step-Down regulator | 1 | 5.00 | 1.39 | Voltage conversion |
| 5V–3.3V logic converter | 1 | 6.00 | 1.67 | Signal adaptation for the pH sensor |
| ON/OFF switch | 1 | 5.00 | 1.39 | General power on/off |
| Transparent acrylic | 1 | 60.00 | 16.67 | Thermoformed cylinder |
| PLA filament | 1 | 75.00 | 20.83 | 3D printing of the structure |
| PCB and electronic components | 1 | 50.00 | 13.89 | Custom electronic board |
| Resistors and connectors | Several | 10.00 | 2.78 | Circuitry and connections |
| Miscellaneous materials | Several | 30.00 | 8.33 | Cables, hoses, screws, and sealing |
| Estimated Total | S/ 582.50 | USD 161.81 | ||
Img. 8: Printed structure and cylinder made by thermoforming transparent acrylic.
The project will integrate multiple processes learned during Fab Academy:
| Area | Process Used | Application in the SpiruSense Project |
|---|---|---|
| 2D Design | PCB design in KiCad | The custom electronic board was designed to integrate the XIAO ESP32-C3 microcontroller, sensors, and actuators of the system. |
| 2D Design | Laser cutting design | Parts were designed for the fabrication of the mold used in thermoforming the acrylic cylinder. |
| 3D Design | CAD modeling in Fusion 360 | The complete structure of the photobioreactor was designed, including the base, lid, central lighting column, sensor supports, and aeration system. |
| Additive Fabrication | 3D printing | The base, lid, air diffuser, central lighting column, and various structural supports of the system were fabricated. |
| Subtractive Fabrication | Laser cutting | Parts were fabricated for the mold used during the thermoforming process of the transparent cylinder. |
| Subtractive Fabrication | CNC milling | Components used in the thermoforming mold were machined, and tests were carried out for the fabrication of auxiliary parts of the system. |
| Subtractive Fabrication | PCB milling | The custom electronic board was fabricated using the PCB milling process with a precision CNC machine. |
| Electronics | Electronic design | The electronic schematic was designed to integrate temperature, pH, TDS, light intensity sensors, LCD screen, lighting, and aeration. |
| Electronics | PCB production | A custom electronic board was fabricated and assembled to centralize connections and reduce external wiring. |
| Electronics | Component soldering | The microcontroller, connectors, resistors, and other electronic components required for system operation were soldered. |
| Programming | XIAO ESP32-C3 programming | The firmware was developed to manage sensors, actuators, WiFi communication, and system monitoring. |
| Programming | Communication with sensors | The reading and processing of data from the DS18B20, TDS, BH1750, and pH sensors were implemented. |
| Programming | Firebase integration | Communication with the Firebase platform was developed to visualize data in real time and remotely control the system. |
| System Integration | Mechanical integration | All structural components were assembled to form a compact and functional photobioreactor. |
| System Integration | Electronic integration | Sensors, LCD screen, lighting, aeration, and PCB were connected within a single operational platform. |
| System Integration | IoT integration | Remote monitoring, data storage, and device control were integrated through WiFi and Firebase. |
Img. 9: Power supply operation tests.
During the development of the project, the following questions will need to be answered:
The project will be considered successful if it achieves the following:
A summary slide named presentation.png was prepared, showing the general project description, the fabrication processes used, the main components, and the expected result. This slide will be updated before the final presentation.
Img. 10: Summary slide of the final project.
A short video named presentation.mp4 was developed, showing the identified problem, the design, fabrication, and system integration process, as well as a demonstration of its operation. The video will be updated and improved before the final presentation.
Video 1: Summary video of the final project.
The files presentation.png and presentation.mp4 will be placed in the root directory of the repository, and their correct linking within the official final presentation schedule will be verified.
| Activity | 03 Jun | 04 Jun | 05 Jun | 06 Jun | 07 Jun | 08 Jun | 09 Jun | 10 Jun | 11 Jun | 12 Jun |
|---|---|---|---|---|---|---|---|---|---|---|
| Definition of the idea | ||||||||||
| Research and references | ||||||||||
| CAD design | ||||||||||
| PCB design | ||||||||||
| Mechanical fabrication | ||||||||||
| Electronic fabrication | ||||||||||
| Sensor integration | ||||||||||
| Programming | ||||||||||
| Firebase integration | ||||||||||
| Functional tests | ||||||||||
| System validation | ||||||||||
| Final slide preparation | ||||||||||
| Final video preparation | ||||||||||
| Final documentation | ||||||||||
| General project review | ||||||||||
| Final Fab Academy presentation | ⭐ |
By June 3, the stages of idea definition, research, CAD design, electronic design, and fabrication of the main components had been completed. During the week prior to the final presentation, the integration of sensors, programming of the XIAO ESP32-C3 microcontroller, and implementation of communication with Firebase will continue. Afterwards, functional tests, system validation, and final adjustments will be carried out. In parallel, the documentation, presentation slide, and demonstration video required for the final presentation on June 12, 2026 will be developed.
SpiruSense arises from the need to improve traditional spirulina cultivation methods used in the laboratory, which depend on handmade containers and manual monitoring. The project seeks to integrate digital fabrication, custom electronics, sensors, and the Internet of Things into a single platform capable of monitoring and controlling the main cultivation variables. During the following weeks, the integration of subsystems, sensor validation, and operation tests will continue in order to obtain a fully operational prototype ready for its final presentation.