(510g) Light-Directed Manipulation and Assembly of Colloids on Solid Substrates | AIChE

(510g) Light-Directed Manipulation and Assembly of Colloids on Solid Substrates

Authors 

Bottom-up assembly of colloids provides a promising way for the on-demand construction of functional nanostructures with controllable configurations at single-particle resolution. The size, shape, and composition of chemically synthesized colloidal building blocks can be precisely tailored down to the atomic scale to fabricate multi-material architectural structures with high flexibility. Many techniques have been reported to assemble individual nanoparticles into complex structures, such as self-assembly, DNA nanotechnology, patchy colloids, and optically controlled assembly. Among them, the optically controlled assembly has the advantages of remote control, site-specific manipulation of single components, applicability to a wide range of building blocks, and arbitrary configurations of the assembled structures. However, for practical on-chip applications, the desired immobilization of the optically assembled colloidal structures onto solid substrates is not trivial.

In this talk, we will present our contributions to the optical manipulation and assembly of architectural materials and structures on solid substrates. We innovate an optothermally-gated photon nudging (OPN) technique as a non-invasive and contactless strategy to achieve versatile nanomanipulation of colloidal particles on a solid substrate through interfacial engineering [1]. This technique takes advantage of a thin surfactant layer to optothermally modulate the particle-substrate interaction, which enables the manipulation of colloidal particles on solid substrates with optical scattering force. Through geometry control, light-directed actuation of colloids on solid substrates can provide additional possibility for on-chip devices [2]. Operated on the solid surfaces without liquid media, OPN can avoid the undesired Brownian motion of nanoparticles in solutions to manipulate individual particles with high accuracy. In addition, the assembled structures can be actively reassembled into new configurations for the fabrication of tunable functional devices [3].

Key references:

[1] J. Li et al. Optical Nanomanipulation on Solid Substrates Via Optothermally-Gated Photon Nudging. Nat. Commun. 2019, 10, 5672.

[2] J. Li et al. Opto-Thermocapillary Nanomotors on Solid Substrates. ACS Nano 2022, 16, 8820-8826.

[3] J. Li et al. Tunable Chiral Optics in All-Solid-Phase Reconfigurable Dielectric Nanostructures. Nano Lett. 2021, 21, 973-979.