<br/>Well-controlled ‘pick-and-place’ of nanoparticles has vast potential in technological applications. These applications are drug delivery, sensing, energy harvesting and transport, data storage, light composites, interfacial and functional modifiers, as well as other applications. Traditional use of prefabricated templates can control both the positional and orientational orders but requires the potentially difficult fabrication of a template. Therefore, our research aims to develop improved assembly strategies at microscales, coherently implemented into additive manufacturing (AM) infrastructure, to readily and simultaneously achieve orientational and positional control of anisotropic nanomaterials over arbitrarily large areas and volumes. The AM proposed here is an in-house designed process supported by layer-by-layer deposition of polymers with alternative and selectively added nanoparticles. The printing and deposition mechanisms from the two-step manufacturing are compatible on the same processing platform that can greatly improve the precision and throughput.<br/><br/>This manufacturing enables the design and fabrication of composites with site-specific optimization of particle orientations, programmable surface morphology, and designable interfacial transitions. One-dimensional (1D) carbons, namely carbon nanofibers (CNF), will be demonstrated as an example here due to their superior anisotropic properties especially the higher conductivity or sensitivity along the fiber axis as compared to that along with the cross- section directions. We used 3D printing for surface morphologies controls and the CNFs were deposited via layer-by-layer self-assembly (LBL) techniques. The samples with different roughness and pattern features were compared for the efficiency of directed self-assembly. The solid-liquid-air interfaces were proven to be critical in determining the selective deposition of CNF for surface conductive paths and sensitivity degrees. The electricity characterizations showed a strong anisotropy along with the fiber alignment directions. This phenomenon was taken advantage of their sensing capabilities. The high sensitivity with exposure to different volatile chemicals was obtained from our research and suggests the potential in health monitoring, human-robotics interactions, microelectronics design, and so on.

Additive manufacturing-enabled selective nanoparticle coatings on polymer surface for sensing functions

ACS Fall 2020 Virtual Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.