Gas-Phase Synthesis, Transport, and Parallel Printing of Charged Nanoparticles; Research Exploring a Discovered Electrodynamic Nanolens Based Transport Concept

• Applicants: Professor Dr. Heiko Jacobs; Dr. Jörg Pezoldt
• Subject Area: Microsystems ; Coating and Surface Technology
• Term: since 2020
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 450218497

- Background: This interdisciplinary proposal is at the cross-section of aerosol science, the synthesis of nanoparticle, and the localized deposition of nanoparticles using novel printing techniques. The proposal describes the investigation of a new transport approach, which supports the localized deposition of particles, potentially in three dimensions. Specifically, in a preliminary study, we have discovered a collection mechanism that enables the localized collection of nanoparticles at high rates. Strongly simplified the process is an electrodynamic Coulomb force directed transport process involving the concept of dielectric lensing structures to direct nanoparticles to predetermined collection or deposition sites. -Preliminary Results: A first publication was published in Nature Communications where we found out that the collection process is several orders of magnitudes faster than the commonly used diffusion only transport. Several immediate applications followed. For example, in a publication entitled “Localized Collection of Airborne Analytes” the increased collection rate was applied to detect airborne molecules. In a subsequent publication entitled “Active Matrix Based Collection of Airborne Analytes: An Analyte Recording Chip Providing Exposure History and Finger Print” the idea of an analyte recording chip is discussed. Recently, and following a different scope nanoparticles have been collected locally at high rates causing the growth of freestanding point-to-point electrical nanowire bridges composed of metallic and semiconducting nanoparticles.- Proposed Research: Going forward we propose a fundamental structured study to provide a better understanding of the underlying process. The mechanism, as far as it is understood, is based on the interplay between high mobility gas ions with airborne nanoparticles, a dielectric lensing layer which is currently bonded to a charge dissipating substrate and a carrier gas. The process leads to localized deposition of the particles. Going forward the static dielectric lensing will no longer be bonded to the substrate. Instead it would be replaced with a dynamic lens array that can be scanned over the surface. This should enable the formation of scanning flux filaments to direct nanoparticle to predetermined points on a surface at high rates. The installation of an experimental platform is proposed to gain access to the relevant process parameter. Specifically, the proposed system can be divided into three parts: nanoparticle source module (partially available), localized deposition module/print head, and process parameter monitor modules (not yet available). The proposed platform and study investigates the effect of the gas ion concentration on focus (WP 1), the role of physical dimensions of individual lens elements (WP 2) and a transition to gated lens arrays (WP 3). The integration of the gained knowledge and incorporation of a multimaterial NP source module (WP 4) is last.

• DFG Programme: Research Grants