Anatase Titanium Dioxide Imparts Photoluminescent Properties to PA2200 Commercial 3D Printing Material to Generate Complex Optical Imaging Phantoms

Abstract

Selective laser sintering (SLS) is a prominent 3D printing modality that typically uses a polyamide (PA) powder as the substrate. One commercially available SLS material is known as PA2200, which is comprised of nylon 12 and titanium dioxide (TiO₂) and is widely used to generate 3D-printed parts. Here, we report a unique optical photoluminescence (PL) characteristic of native, white PA2200, in which it yields a persistent, phosphorescence-type emission. An analysis of luminescence imaging data with emission measurements demonstrated that the anatase phase of the titanium dioxide additive is the source of the persistent PL properties. This characteristic of PA2200 enables advanced optical imaging applications, as demonstrated by luminescence imaging of an anatomical rat skeleton and a novel Derenzo-type phantom on a commercial image station. In summary, the light emission properties of PA2200 induced by the presence of anatase titanium dioxide open the door to a vast new array of complex optical applications, including the generation of imaging phantoms for training, calibration, and quality control.

Keywords: 3D printing; derenzo phantom; imaging phantoms; optical imaging; optical properties; photoluminescence.

Figure 1

Photoluminescent signal of PA2200 and related components.

Figure 2

Normalized emission spectrum of the white PA2200 block and pure anatase TiO₂ derived from photoluminescence (PL) images (shown at top).

Figure 3

Three−dimensional (3D) printed PA2200 anatomical phantom of rat skeleton. (a) Photograph of a white PA2200 3D printed phantom. (b) PL image of phantom taken with open emission after preliminary charge with ambient light.

Figure 4

Optical imaging of Derenzo-style optical imaging phantom with varied CCD bin states. In the 2 × 2 binning setting, dead pixel artifacts were present, as highlighted in red.