UP NEXT: Kaiwen Hsiao, Texas A&M University

ABSTRACT

Architected polymeric materials play a significant role in energy-water, microelectronics and biomedical applications. Major advances in continuous-wavelength light-based additive manufacturing (AM) have enabled scalable fabrication of complex architected polymeric materials at the micrometer length scale. Nevertheless, there exists several knowledge gaps in advancing structural precision towards sub-diffraction limited resolution (< 250 nm), while maintaining process scalability and material property control. In this talk we aim to discuss our recent efforts in addressing these challenges, with nano-resolution structural precision achieved by top-down and bottom-up approaches, and material property engineering with photo- and thermally active precursors.

In the first part of the talk, we will focus on the introduction of dual-wavelength 3D printing platform coupled with controlled living radical polymerization to tackle the diffraction-limited patterning. We will discuss the critical timescales of reaction-diffusion mechanism elucidated with experiment, simulation and theory and provide discussion on macroradical reactivity, projection optics exposure area, and dual-wavelength pattern proximity to enter resolution-enhancement regime. In the second part of the talk we will focus on the bottom-up approach using macromolecular-amphiphilic templates for controlling self-assembly nano-morphologies formation during rapid photo-crosslinking in AM platforms. The single-digit nanometer morphologies preservation is found before and after printing confirmed by with SAXS and rheology. Furthermore, the onset of polymerization driven microphase separation occur due to the thermodynamic depletion effect is found to lead to formation of nested bi-continuous hierarchical structures. In the last part of my talk, I will discuss our recent development of photo- and thermally active polymer precursors as a photocurable material for engineering material modulus, stretchability and toughness, that is capable of patterning with micro-meter architectural complexity. Taken together, our effort aims to address the fundamental challenges in projection-based, additive manufacturing platforms, and provide a pathway towards fabrication of high-resolution and high-performance polymeric materials.