Work

Photocatalytic Magnetic Microgyroscopes with Activity-Tunable Precessional Dynamics

Year: 2024

Type: article

Abstract: Magnetic nano/microrotors are passive elements spinning around an axis due to an external rotating field while remaining confined to a plane. They have been used to date in different applications related to fluid mixing, drug delivery, or biomedicine. Here we realize an active version of a magnetic microgyroscope which is simultaneously driven by a photoactivated catalytic reaction and a rotating magnetic field. We investigate the uplift dynamics of this colloidal spinner when it precesses around its long axis while self-propelling due to the light induced decomposition of hydrogen peroxide in water. By combining experiments with theory, we show that activity emerging from the cooperative action of phoretic and osmotic forces effectively increases the gravitational torque, which counteracts the magnetic and viscous ones, and carefully measure its contribution. Finally, we demonstrate that by modulating the field amplitude, one can induce hysteresis loops in the uplift dynamics of the spinners.

Source: Nano Letters

DOI: 10.1021/acs.nanolett.4c03386

Authors: Dolachai Boniface, Arthur V. Straube, Pietro Tierno

Institutions: Universitat de Barcelona, Zuse Institute Berlin, Freie Universität Berlin, Institut de Nanociència i Nanotecnologia de la Universitat de Barcelona

Language: English

Topic: Micro and Nano Robotics

Subfield: Condensed Matter Physics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,500