Title: All‐Optical Platform for the 3D Assembly and Immobilization of Nano‐ and Microstructures

Abstract: The ability to assemble arbitrary 3D structures using nano‐ to micron‐scaled colloidal building blocks has several interesting potential applications, including photonic, electronic, and biological. To achieve this, the combination of optical tweezers (OT) with two‐photon polymerization (TPP), offers the advantage of complete 3D optical manipulation and immobilization of particles without the need for specialized functionalization of the constituent particles. Unlike previous approaches, we demonstrate that utilizing high‐repetition rate femtosecond‐laser pulses, rather than the traditional continuous‐wave (cw) lasersource, permits
optical tweezing with intensities below the threshold for TPP, and thus enables both OT and TPP using the same laser source. We apply this approach for selective tweezing and immobilization of colloids(STIC) to various particle types. As an all‐optical platform, STIC provides an opportunity to both freely manipulate and immobilize objects in three spatial dimensions using a single platform. This talk reviews the operational principle of STIC and provides proof‐of‐principle experiments that highlight its capabilities on a diverse array of materials including bacterial cells, and select 2D materials. The current challenges and opportunities of this platform are also discussed.