Login to Access Video or Poster Abstract: MP25-09
Sources of Funding: Partial Funding through Boston Scientific

Introduction

Three-dimensional (3D) printing or additive printing is a new technology that allows for construction of complex shapes and designs outside the constraints of traditional manufacturing techniques. Traditional 3D printing was limited to thermosensitive plastics that have limited medical applications. Herein, we describe the application of a novel process that allows for 3D printing of shape memory alloys (SMA). Using our previously described concept of a SMA penile prosthesis for the treatment of erectile dysfunction, we sought to construct an intracavernosal cylinder using 3D printing technology.

Methods

A computer-aided design (Solidworks) 3D construct of the exoskeleton for our SMA penile prosthesis was fed into a computer-controlled 3D Bio Plotter (EnvisionTec, Germany). A novel custom printing ink consisting of pre-alloyed nickel-titanium (Ni-Ti) powder suspended in a Poly Lactic-co-Glycolic Acid (PLGA) and tri-solvent mixture was serially added in a precise 3D pattern to produce a green body reflecting the CAD geometry. Subsequently, the green body was sintered at a temperature of 1200 C, just 20-30 C below the melting point of NiTi, for 5 hours to produce the final product. This was then evaluated for its mechanical properties compared to our Ni-Ti extruded tube.

Results

A 1:4 scale version of the exoskeleton of our novel SMA penile prosthesis was constructed using 3D printing technology from Ni-Ti powder suspended in a PLGA/solvent mixture. Total printing time was 20 minutes (figure 1). After sintering, there was a ~30% volume reduction, which was homogenous in 3 directions. Mechanical properties were evaluated and found to be comparable to non-3D printed prototypes and SMA properties maintained.

Conclusions

3D printing is a viable option for construction of SMA devices, including penile prostheses. The 3D-printed SMA prototype maintained its unique biomechanical properties. This technology opens up the possibility of more complex structures and customization without the constraints of traditional manufacturing techniques.

Funding

Partial Funding through Boston Scientific