# Radiation Attenuation Calculation of 3D-Printed Polymers Across Variable Infill Densities and Phase Angles for Nuclear Medicine Applications

## TL;DR

This study examines how infill density and phase angle affect the radiation shielding properties of 3D-printed polymers for use in nuclear medicine.

## Contribution

The study introduces a detailed analysis of radiation attenuation in 3D-printed polymers with variable infill densities and phase angles.

## Key findings

- TPU showed the highest radiation attenuation at 30% infill density with a coefficient of 20.199 cm−1.
- Infill density significantly affects attenuation, while phase angle does not, as confirmed by statistical analysis.
- TPU is the most suitable material for radiation protection due to its high sensitivity to infill density.

## Abstract

This study investigates the modulation effects of varying infill densities and phase angles on the radiation attenuation properties of three 3D-printed polymers: acrylonitrile butadiene styrene (ABS), polylactic acid (PLA), and thermoplastic polyurethane (TPU). Using the EpiXS software for radiation attenuation calculations, the study assessed the linear attenuation coefficients (LACs) of the materials under different infill densities (30%, 50%, 70%, 90%, and 100%) and phase angles (0°, 30°, 45°, 60°, and 90°) for radiation in the 1–100 keV energy range, which corresponds to the X-ray spectrum. TPU demonstrated the highest attenuation values, with a baseline coefficient of 20.199 cm−1 at 30% infill density, followed by PLA at 18.835 cm−1, and ABS at 13.073 cm−1. Statistical analysis via the Kruskal–Wallis test confirmed that infill density significantly impacts attenuation, while phase angle exhibited no significant effect, with p-values exceeding 0.05 across all materials. TPU showed the highest sensitivity to infill density, with a slope of 1.1194, compared to 0.7257 for ABS and 0.9251 for PLA, making TPU the most suitable candidate for radiation protection applications, particularly in applications where flexibility and high attenuation are required. The findings support the potential of 3D printing to produce customized, cost-effective radiation protection gear for medical and industrial applications. Future work can further optimize material designs by exploring more complex infill geometries and testing under broader radiation spectra.