Flow pattern in the vicinity of self-propelling hot Janus particles.
We study the temperature field and the resulting flow pattern in the vicinity of a heated metal-capped Janus particle. If its thickness exceeds about 10 nm, the cap forms an isotherm and the flow pattern comprises a quadrupolar term that decays with the square of the inverse distance ~r(-2). For much thinner caps the velocity varies as ~r(-3). These findings could be relevant for collective effects in dense suspensions and for the circular tracer motion observed recently in the vicinity of a tethered Janus particle.
LOMA, Université de Bordeaux & CNRS, 351 cours de la Libération, 33405 Talence, France.
Thomas
T
Bickel
Arghya
A
Majee
Alois
A
Würger