Stereolithography: Enabling Polymer Network and Multi-Scale Structure Control

This award supports fundamental research that integrates material chemistry and mechanics to define a technology which can lead to advanced manufacturing of 3D printed thermosets with enhanced mechanical properties. Thermoset structures containing stiff and soft domains that mimic the hierarchical structure of bone, nacre, bamboo and pearlite steels will be developed by using stereolithography 3D printing in conjunction with phase separation.

The experimental work will be guided by modeling to optimize the network structure and the multiscale architecture of the material, in order to achieve strength and toughness of the additive manufactured (AM) parts superior to those of the structurally homogeneous thermosets used today. Polymer nanocomposite AM parts are increasingly important for applications in dental, biomedical, wearable electronics, aerospace, and automotive industries.

Therefore, results from this research will benefit the U.S. economy and society. This project integrates research with an education plan, which encompasses course development, education of graduate students, integration of undergraduate students in research, outreach to K-12 and the promotion of STEM.

The objective of this research is to innovate the photopolymerization 3D printing technique called stereolithography (SLA) to allow for the production of thermosets with network structure and architecture modulated on multiple scales. The project aims to develop material design rules for heterogeneous thermosets and to establish new SLA methods by combining photo-crosslinking with phase separation.

This activity will (i) develop SLA as an additive manufacturing method for thermosets with structure controlled on multiple length scales, including on scales finer than the printing resolution, and (ii) develop the concept and the methods to design the multiscale structure so as to enhance its toughness without compromising the strength and stiffness of the thermoset. This will be achieved by integrating modeling and experimentation.

The developed technologies will be applicable to other polymeric systems to control these and other sets of properties, such as the thermal and electrical conductivities. This research will also provide education in advanced manufacturing, materials modeling and polymer research to graduate and undergraduate students, while dissemination and outreach to K-12 will increase the impact of the project activities.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.