Bottom-illuminated orbital shaker for microalgae cultivation.

Area of Science:

• Biotechnology
• Open-source hardware
• Algal cultivation

Background:

• Microalgae cultivation requires specialized equipment for agitation and illumination.
• Commercial systems can be expensive, limiting accessibility for low-resource laboratories and educational settings.
• Existing do-it-yourself (DIY) systems often lack consistent and controllable light intensity.

Purpose of the Study:

• To design and build a cost-effective, open-source bottom-illuminated orbital shaker for microalgae cultivation.
• To provide a reliable and controllable alternative to commercial microalgae growth instruments.
• To support research and education in low-resource environments.

Main Methods:

• Development of an open-source hardware instrument with a focus on low cost, simplicity, and low power consumption.
• Integration of adjustable illumination (26–800 µmol·m⁻²·s⁻¹) with programmable light/dark cycles and variable agitation (0–210 RPM).
• Documentation of the build process with open-source protocols, design files, and source code.

Main Results:

• The illuminated orbital shaker was constructed for approximately £300 and can be assembled in two days.
• The device features a 20 cm × 15 cm illuminated area suitable for multiple flasks (e.g., three T75 or six 100 ml).
• Instrument performance was validated using microalgae species *Desmodesmus quadricauda* and *Chlorella vulgaris*.

Conclusions:

• The developed open-source orbital shaker provides a consistent, controllable, and affordable solution for microalgae cultivation.
• The design is flexible and adaptable for various experimental needs and different orbital shaker models.
• This instrument is particularly beneficial for low-resource laboratories and educational institutions.