Direct 3-D printing of complex optical phantoms using dynamic filament mixing

Area of Science:

• Biomedical Optics
• Additive Manufacturing
• Materials Science

Background:

• Accurate optical phantoms are essential for validating diffuse optics instruments.
• Existing methods for creating heterogeneous optical phantoms can be complex and expensive.
• Programmable control over optical properties like absorption and scattering is highly desirable.

Purpose of the Study:

• To present a novel, low-cost method for 3-D printing complex heterogeneous optical phantoms.
• To achieve programmable, tissue-mimicking absorption and scattering properties using readily available materials.
• To demonstrate the utility of these phantoms for quality assurance in diffuse optics.

Main Methods:

• Utilized commercially available multi-color mixing 3-D printers and polylactic acid filaments.
• Systematically characterized optical properties (absorption and reduced scattering coefficients) at various filament mixing ratios.
• Validated a linear-mixing model correlating filament ratios to optical properties.

Main Results:

• Successfully fabricated complex heterogeneous optical phantoms with tunable optical properties.
• Demonstrated a linear relationship between filament mixing ratios and resulting optical properties.
• Observed an average error of 12%-15% between predicted and characterized optical properties.

Conclusions:

• The proposed 3-D printing technique offers a broadly accessible and low-cost approach to creating sophisticated optical phantoms.
• This method enables the generation of anatomically complex phantoms with tunable, tissue-relevant optical properties.
• The developed phantoms can support quality assurance for diffuse optics instruments and methodologies.