Collaborative Research: Sub-Voxel Molecular Patterning of Actuators and Photonic Structures in 3-Dimensional Free-Forms

Texas A&M Engineering Experiment Station, College Station TX

Investigators

Abstract

This grant supports research into the 3D printing of macroscopic polymeric structures with an engineered molecular order that can be defined at the sub-micrometer-scale. The molecularly engineered structures with unusual optical and mechanical properties in easily printed structures with arbitrary form factors could improve many application areas. These properties include structural color that can change in response to the surrounding environment and the ability to create artificial muscles that generate mechanical work from an ambient stimulus. Control of the molecular structure and composition in printable materials is the key enabler of these functionalities. Fundamental research advances can enable soft robots that integrate actuators and sensors within a 3D printed structure. The ability to self-sense actuation and optically report deformation state allows for the development of new control strategies in soft robots. This will be key to their potential applications in future medical devices for minimally invasive surgery and industrial applications that require manipulation of fragile objects. This research will also result in training opportunities for undergraduate and graduate students who will be exposed to emerging concepts in manufacturing with active soft matter. Outreach initiatives targeted at the K-12 levels will prioritize inclusion of traditionally underrepresented groups. This project will control the interplay between surface anchoring, magnetically-mediated alignment, and chiral self-assembly of liquid crystal monomers in a stereolithographic printing system. The effect of the monomer’s structure and composition on the chiral nematic order in 3D printed voxels will be understood as a function of the printing parameters. Process-structure relationships will be used to voxelate the blueprinted microstructure both in-plane and through-thickness in freeform geometries. Fundamental limits on the resolution at which the molecular patterning can be enforced will be explored. This will be used to inform the space of optical and mechanical properties, as well as their sensitivity to an applied stimulus. Ultimately, this study envisions 3D printed structures that are capable of morphing and self-reporting state to an observer via a coupling of the mechanical responses to the optical properties. 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.