Session: 16-01-01: Government Agency Student Poster Competition

Paper Number: 142527

142527 - 3d Printing-Enabled Nanoparticle Assembly for Versatile Applications 

In order to advance science and technologies, precise control over material properties can be achieved by tailoring assemblies of nanoparticles. Specifically, when plasmonic nanoparticles interact with light, they exhibit special resonances called surface plasmon resonances (SPR) that are caused by the localized oscillation of electrons. Thus, emerging functionalities like sub-wavelength field enhancement, high surface sensitivity, electrical conductivity, and metamaterials are based on the ability to customize plasmonic nanoparticle assemblies and, consequently, resonant interactions. These applications hold great promise for the energy, environment, computing, communication, and biosensing fields. However, because of the inherent shapelessness of the liquidus nanoparticle dispersion solution, it is difficult to integrate solution-phase nanoparticle assemblies into deterministic large-scale solid architectures. To achieve integrated macroscopic shape control, conventional thin-film manufacturing techniques like casting, Langmuir-Blodgett, and doctor blading have been used to create film-shaped nanoparticle assemblies. Yet these techniques can only produce relatively simple external shapes or geometries, although the assembled nanoparticle patterns can be preserved. 

 

Simultaneously, the advancement of 3D printing technologies, which are distinguished by layer-by-layer additive manufacturing, has yielded a special capacity for complex and accurate prototyping of materials, adaptability, and sustainability. Digital light processing (DLP), liquid deposition modeling (LDM), and fused deposition modeling (FDM) are examples of widely utilized techniques that have shown remarkable effectiveness. These methods, which are characterized by the sequential stacking of two-dimensional patterns, can be applied to the precise geometric control construction of intricate three-dimensional structures. On the other hand, they typically lack diverse nanoscale patterning manufacturing capabilities and functionalities, and have low printed resolutions (> 100 μm). Recently, feature sizes have been pushed into the nanometer range by newly developed nanoscale 3D printing processes as electrohydrodynamic (EHD) printing and two-photon polymerization (2PP). A critical technical barrier remains in developing an accessible high-resolution manufacturing route integrated with high-throughput 3D printing programmability that can lead to functional materials at the nanoscale.

 

In this work, we have successfully combined 3D printing with plasmonic light-driven nanoparticle self-assembly to create patterns of nanoparticles while maintaining geometric control and macroscale prototyping. Our method initially defines macroscopic designs using FDM 3D printing, where gold nanoparticles, like Pluronic F-127 (Pf-127), are included into the printing ink. Then, by utilizing the photothermal characteristics and the surface plasmon resonance (SPR) of Au NPs under light stimulation at the designated wavelength, we actively direct the bottom-up assembly of the added gold nanoparticles (AuNPs). In particular, the resonant oscillation of conduction band electrons enables efficient absorption of input radiation and its prompt conversion to heat through non-radiative relaxation and electron-lattice collisions when AuNPs are activated by light at their SPR frequency. This highly localized photothermal effect generates steep thermal gradients in the vicinity of AuNPs, which induces thermophoretic forces surrounding nanoparticles along the optical path within the printing ink. By optically tuning excitation light intensity, the distribution of these thermal fields can direct the nanoparticle diffusion and assembly in a controllable fashion. This synergistic integration of top-down 3D printing and optical-guided assembly enables novel hierarchical nano-to-macro structure constructions.

 

Presenting Author: Arunachalam Ramanathan University of Georgia

Presenting Author Biography: I am currently in my 2nd year of PhD with emphasis on Material and Mechanics under the supervision of Dr. Kenan Song and Dr. Sui Yang. My research interests includes advanced materials, 3D printing, carbon based fillers, polymers and composites, nanoparticle assembly.

Authors:

Arunachalam Ramanathan University of Georgia
Kenan Song University of Georgia
Shuai Feng Arizona State University