Nanoalignment by critical Casimir torques
Artikel i vetenskaplig tidskrift, 2024
The manipulation of microscopic objects requires precise and controllable forces and torques. Recent advances have led to the use of critical Casimir forces as a powerful tool, which can be finely tuned through the temperature of the environment and the chemical properties of the involved objects. For example, these forces have been used to self-organize ensembles of particles and to counteract stiction caused by Casimir-Liftshitz forces. However, until now, the potential of critical Casimir torques has been largely unexplored. Here, we demonstrate that critical Casimir torques can efficiently control the alignment of microscopic objects on nanopatterned substrates. We show experimentally and corroborate with theoretical calculations and Monte Carlo simulations that circular patterns on a substrate can stabilize the position and orientation of microscopic disks. By making the patterns elliptical, such microdisks can be subject to a torque which flips them upright while simultaneously allowing for more accurate control of the microdisk position. More complex patterns can selectively trap 2D-chiral particles and generate particle motion similar to non-equilibrium Brownian ratchets. These findings provide new opportunities for nanotechnological applications requiring precise positioning and orientation of microscopic objects.
Författare
Gan Wang
Göteborgs universitet
Piotr Nowakowski
Max-Planck-Gesellschaft
Ruder Boskovic Institute
Universität Stuttgart
Nima Farahmand Bafi
Universität Stuttgart
Max-Planck-Gesellschaft
Polish Academy of Sciences
Benjamin Midtvedt
Göteborgs universitet
Falko Schmidt
Eidgenössische Technische Hochschule Zürich (ETH)
Agnese Callegari
Göteborgs universitet
Ruggero Verre
Chalmers, Mikroteknologi och nanovetenskap, Nanotekniklaboratoriet
Mikael Käll
Chalmers, Fysik, Nano- och biofysik
S. Dietrich
Max-Planck-Gesellschaft
Universität Stuttgart
Svyatoslav Kondrat
Polish Academy of Sciences
Max-Planck-Gesellschaft
Universität Stuttgart
Giovanni Volpe
Göteborgs universitet
Nature Communications
2041-1723 (ISSN) 20411723 (eISSN)
Vol. 15 1 5086Ämneskategorier (SSIF 2011)
Reglerteknik
DOI
10.1038/s41467-024-49220-1