Additive manufacturing (AM) has significantly impacted various industries and has the potential to continue transforming sectors in the near future. A lesser-known type of AM, digital light processing (DLP), involves using light to create objects one layer at a time by converting liquid resin into solid parts. While DLP is widely used in industrial and dental applications, its effectiveness is limited by the viscosity of the resins required for high-resolution printing. Solvent-based resins are often used to reduce viscosity, but this leads to issues such as part shrinkage and residual stress as the solvent evaporates.
Researchers at Duke University recently developed a solvent-free polymer for DLP printing, which addresses the problems associated with solvent-based resins. This new polymer eliminates issues like shrinkage and improves the mechanical properties of printed parts while maintaining the ability to degrade in the body. By optimizing monomers and using a synthetic technique to create a low-viscosity polymer, the team was able to develop a material suitable for DLP printing without any dilution. This innovation represents a significant advancement in the field of 3D printing with degradable polymers.
In the process of creating the new polymer, the researcher, Maddiy Segal, utilized an empirical approach similar to cooking a meal, adjusting the monomers and chain length until achieving the desired properties. Segal conducted numerous experiments to find the optimal combination of ingredients, heating, and testing the materials to fine-tune the polymer. Her persistence and dedication culminated in the development of a material that met her criteria of being shrink-resistant, strong, biocompatible, and degradable, key attributes for medical applications.
The goal of Segal’s research is to apply this innovative technique to the production of biodegradable medical implants. The current challenge with non-degradable implants is the need for multiple surgeries to implant and subsequently remove them. By developing implants that degrade naturally within the body, the necessity for additional surgeries can be eliminated. This technology could have applications in various medical fields, including temporary implants that degrade over time and soft robotics where a degradable, soft material is required.
The potential for this solvent-free DLP printing technique extends beyond medical implants to other applications where degradable materials are essential. The developed material could be used as a bone adhesive for temporary fracture fixation or in soft robotics, facilitating the creation of degradable components for various purposes. The versatility and biocompatibility of this new polymer make it a promising innovation in the field of additive manufacturing.
Supported by funding from the National Institutes of Health, this research at Duke University has led to a provisional patent application for the technology. The development of a solvent-free polymer for DLP printing represents a significant step forward in the production of degradable materials for various applications, particularly in the medical field. By eliminating the use of solvents, this innovation has the potential to revolutionize the way degradable polymers are produced and utilized in additive manufacturing processes.