@misc{10481/106251,
year = {2025},
month = {7},
url = {https://hdl.handle.net/10481/106251},
abstract = {In the field of microdroplet manipulation, optical tweezers have been used to form and grow droplets,
to transport them, or to measure forces between droplet pairs. However, the exploration of out-ofequilibrium phenomena in optically trapped droplets remains largely uncharted. Here, we report the
rotation of biphasic droplets fabricated by co-emulsifying two immiscible liquids (i.e., hydrocarbon
and fluorocarbon oils) with a refractive index mismatch in water. When trapped, droplets of a specific
geometry rotate around the axis of the laser beam, in what appears to be a dissipative, out-ofequilibrium phenomenon. The rotational frequency, obtained from image analysis, is stable and
proportional to the beam power. Remarkably, droplets that do not interact with the trapping beam can
also be rotated indirectly. This is achieved by positioning the droplets at the center of a circular
arrangement of multiple, sequentially activated traps, so that the droplet orients towards the location of
the active trap. Altogether, our results demonstrate out-of-equilibrium phenomenology in optically
trapped biphasic droplets, which would inspire the development of devices based on them (e.g.,
optically induced mixing, etc.). In addition, they may shed light on fundamental principles of optical
manipulation of asymmetric particles.},
organization = {FEDER/Junta de Andalucía - Conserjería de Transformación Económica, Industria, Conocimiento y Universidades (grant P20_00340)},
organization = {European Social Fund - Ministry of Economic Transformation, Industry, Knowledge and Universities of the Junta de Andalucía
(PAIDI 2020)},
organization = {MCIN/AEI/10.13039/501100011033 - Universidad de Granada (IJC2018-037951-I)},
organization = {MICIU/AEI/10.13039/501100011033 - ERDF/EU (PID2021-127427NB-I00)},
publisher = {Royal Society of Chemistry},
title = {Windmill droplets: optically induced rotation of biphasic oil-in-water droplets},
doi = {10.1039/d5sm00273g},
author = {del Pozo, Jesús J. and Bonhome-Espinosa, Ana B. and Sun, Wei and Gutiérrez-Ariza, Carlos and Rica-Alarcón, Raúl Alberto and Rodríguez-Arco, Laura},
}