3D-printable portable open-source platform for low-cost lens-less holographic cellular imaging

Area of Science:

• Microscopy
• Optical Engineering
• Biomedical Imaging

Background:

• Conventional light microscopy faces cost and accessibility barriers for micro-object imaging.
• Digital holographic microscopy offers a promising, cost-effective alternative for various environments, including space.
• Sophisticated reconstruction algorithms and system design are crucial but often expensive.

Purpose of the Study:

• To present an open-source, low-cost digital inline holographic microscope platform.
• To demonstrate a system built from off-the-shelf components with a total cost under $190.
• To validate the platform's imaging capabilities for various micro-objects.

Main Methods:

• Utilized a Blu-Ray semiconductor-laser-pickup or LED, pinhole, and 3D-printed housing.
• Integrated a single-board computer and camera with open-source Fresnel-Kirchhoff reconstruction software.
• Employed 3D printing for housing and mechanical components, ensuring an open-source design.

Main Results:

• Achieved 1.55 μm spatial resolution with the laser-pickup and 3.91 μm with the LED source.
• Successfully imaged label-free micro-spheres (6.5 μm), human red blood cells (~8 μm), and plant cells (50 μm).
• Validated imaging capability through contrast quantification using a standardized test target.

Conclusions:

• The presented 3D-printable, portable, open-source platform is a versatile and low-cost imaging solution.
• This modular design is suitable for high- and low-resource settings globally.
• The fully-open design promotes accessibility and further development in micro-object imaging.