Inexpensive Optical Projection Tomography on a Mobile Phone Platform

TL;DR

This paper introduces a low-cost, portable optical projection tomography system built on a mobile phone platform, capable of 3D microscopy with high resolution for educational and resource-limited applications.

Contribution

The work demonstrates a complete, inexpensive OPT system using a mobile phone, achieving high-resolution 3D imaging with a total cost of about 50 USD.

Findings

Achieved 3.91 μm resolution in 3D reconstructions.

Successfully imaged zebrafish phantom with visible anatomical features.

System cost is approximately 50 US dollars excluding the phone.

Abstract

This work presents an inexpensive optical projection tomography (OPT) system built on a mobile phone platform for three-dimensional optical microscopy. The system uses an iPhone camera together with a low-cost commercial microscope lens attachment, a stepper motor for sample rotation, LED illumination, and custom 3D-printed components, with a total component cost of approximately 50 US dollars excluding the phone. To support system evaluation, we also developed a low-cost method for fabricating a zebrafish phantom by embedding fixed larvae in UV-cured resin. Camera calibration was performed using a checkerboard target, and effective magnification was estimated with images of a 1951 Air Force resolution target. Projection images acquired during sample rotation were converted to attenuation images and corrected for field nonuniformity. Each slice was reconstructed with filtered backprojection and the resulting slices were stacked into a 3D volume. The completed system achieved a resolution of 3.91 $\mu m$ and produced volumetric reconstructions in which anatomical features of the zebrafish phantom, including the spine, were clearly visible. These results demonstrate that mobile-phone-based OPT can provide accessible, portable, and low-cost 3D microscopy, with potential utility for education, field work, and resource-limited settings.