Nanoalignment by Critical Casimir Torques

• DOI: 10.48550/arxiv.2401.06260
• Publication Date: 2024-01-01
• Authors: Wang Gan; Piotr Nowakowski; Nima Farahmand Bafi; Benjamin Midtvedt; Falko Schmidt; Ruggero Verre; Mikael Käll; S. Dietrich; Svyatoslav Kondrat; Giovanni Volpe
• Keywords: Stiction; Position (finance); Particle (ecology)

The manipulation of microscopic objects requires precise and controllable forces torques. Recent advances have led to the use critical Casimir as a powerful tool, which can be finely tuned through temperature environment chemical properties involved objects. For example, these been used self-organize ensembles particles counteract stiction caused by Casimir-Liftshitz forces. However, until now, potential torques has largely unexplored. Here, we demonstrate that efficiently control alignment on nanopatterned substrates. We show experimentally corroborate with theoretical calculations Monte Carlo simulations circular patterns substrate stabilize position orientation disks. By making elliptical, such microdisks subject torque flips them upright while simultaneously allowing for more accurate microdisk position. More complex selectively trap 2D-chiral generate particle motion similar non-equilibrium Brownian ratchets. These findings provide new opportunities nanotechnological applications requiring positioning