Ice-phase optothermal tweezers
摘要
The deterministic and reconfigurable assembly of heterogeneous micro- and nanostructures remains challenging, where Brownian motion, nonspecific interfacial adsorption, and method-specific material constraints undermine precision and cross-material compatibility. Here, we present ice-phase optothermal tweezers (IOT), a platform that utilizes the ice–water interface for fast (10–100 μm/s), programmable manipulation of diverse targets, including dielectric/metal nanoparticles, proteins, DNA, and even microbubbles within ice, which have long been regarded as passive byproducts of freezing. In this scheme, the optothermally induced mobile melting zone within the ice matrix enables directed transport and nanostructure assembly with nanometer-scale resolution. We further fabricate multi-material heterostructures with tailored anisotropic and chiral optical responses, enabling applications in chiral photonics and polarization-controlled nano-optical devices under cryogenic environments. Accordingly, by unifying precise control of micro- and nano-entities across fluidic and solid-state regimes, IOT provides a general cryogenic platform for meta-structure fabrication, in-situ optical spectroscopy, and nanoparticle-interaction studies.