Regensburg 2019 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
BP: Fachverband Biologische Physik
BP 12: Poster II
BP 12.74: Poster
Dienstag, 2. April 2019, 14:00–16:00, Poster B2
Topological insulator and semiconductor beads as micro-oscillators induced by laser beam — •Warlley H. Campos1,2, Tiago A. Moura1, Jakson M. Fonseca1, Joaquim B. S. Mendes1, Márcio S. Rocha1, and Winder A. Moura-Melo1 — 1Departamento de Física, Universidade Federal de Viçosa, Viçosa 36570-900, Brazil — 2Institut für Physik, Johannes Gutenberg-Universität Mainz, Mainz 55128, Germany
The optical tweezers (OT) is a powerful technique used to trap microscopic objects with light. It became an essential tool for high accuracy measurements in areas such as biological and soft matter physics. We perform the first experimental studies upon the optical trapping of topological insulator (TI) [Bi2Te3 and Bi2Se3] and Germanium (Ge) microparticles under a Gaussian laser beam OT. For such materials gradient and radiometric forces compete, generating oscillatory dynamics perpendicular to the optical axis. We describe the oscillations with an effective model that captures the forces acting on the particle, amplitude of oscillation, periodicity and their dependence on particle size. Ge beads oscillate in a preferential direction determined by the polarization of the laser beam, this was not observed for neither of the TI materials. Our results open an avenue for dynamical measurements with unprecedented simplicity and purely optical control. Among the possible applications for the near future, stand out the optical rheology of soft matter interfaces and biological membranes, as well as dynamical force measurements in macromolecules and biopolymers.