As the principal investigator, assistant professor Roseanne Warren received a three-year NSF Nanomanufacturing (CMMI – Civil, Mechanical and Manufacturing Innovation) grant for collaborative research with University of Maryland mechanical engineering assistant professor Ryan Sochol, entitled, “Liquid phase atomic layer deposition of thin films on nanoparticles using three-dimensionally printed microfluidics.”

“Atomic layer deposition (ALD) is a well-established nanofabrication approach that uses sequential exposure to gas-phase reactants to deposit highly conformal thin films with monolayer (less than 0.1 nm) thickness control,” says Warren. “In this research we’re moving ALD to the liquid phase and depositing ultra-thin coatings on nanoparticles with high precision. I’m very excited to begin working on this new nanoscale manufacturing technology!”

Nanoparticles are particles between 1 and 100 nanometer in size that possess unique, size-dependent properties due to their high surface area-to-volume ratios. Functional nanoparticles have the potential to benefit society through applications such as drug delivery, magnetic resonance imaging, renewable energy, optoelectronics, and catalysis. These applications rely on an ability to precisely customize the surface chemistry of nanoparticles using thin-film coatings. For reference it takes approximately 100,000 nanometers to equal the size of a human hair! Given these small sizes, uniformly depositing thin films on nanoparticles has many challenges.

This research meets the challenges by combining the monolayer-by-monolayer deposition principle of conventional atomic layer deposition with a microfluidic nanoparticle manipulation approach to achieve a new nanomanufacturing technology the PIs term ‘Liquid Phase Atomic Layer Deposition.’ It is hypothesized that the controlled solid-liquid interface phenomena of Liquid Phase Atomic Layer Deposition will yield a high degree of precision and uniformity for nanoparticle thin-film coating. The engineering of parallel three-dimensional microfluidic reactors, constructed by means of two-photon direct laser writing-based additive manufacturing, will ensure that this method is also high throughput. The research team will investigate the phenomenon of Liquid Phase Atomic Layer Deposition through fundamental experimental studies, computational fluid dynamics simulations, and multiphysics finite element modeling.

Two Ph.D. students – one at the U and one at the University of Maryland – will be funded on this grant. Additionally, this research collaborates with U communication assistant professor Leona Yi-Fan Su, to support public engagement with nanotechnology through hands-on educational demonstrations of nanoparticle applications, with a focus on promoting inclusion for groups historically underrepresented in manufacturing research such as women and minorities.

To learn more about Dr. Warren and her research please visit her Advanced Energy Innovations Laboratory.