BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Microscale flows: bubbles and active droplets - Daniel Booth (Univ
 ersity of Warwick)
DTSTART:20251105T130000Z
DTEND:20251105T140000Z
UID:TALK237301@talks.cam.ac.uk
CONTACT:Emma
DESCRIPTION:*Bubbles in Hele-Shaw cells*: I will present a model for the m
 otion of bubbles in a Hele-Shaw cell. I consider the regime where the bubb
 les are large enough to be flattened by the cell walls into a pancake-like
  shape\, but small enough such that each bubble remains approximately circ
 ular when viewed from above. In this regime\, the flow dynamics are determ
 ined by a single dimensionless parameter\, the “Bretherton parameter”\
 , and I find situations in which the bubble can travel either slower or fa
 ster than the background flow velocity.  In a system of two bubbles of dif
 ferent radii\, if the smaller bubble is in front\, it will be overtaken by
  the larger bubble. Under certain circumstances\, the bubbles may avoid co
 llision by rolling over one another while passing. For a train of three or
  more bubbles moving along a Hele-Shaw channel\, we observe longitudinal w
 aves that propagate forwards or backwards along the bubble train\, dependi
 ng on flow conditions\, resembling a Hele-Shaw Newton’s cradle.\n\n*Cont
 rollable flow through active droplets*: Precise\, localised flow control i
 n microfluidic devices remains a difficult challenge. In this talk\, I dem
 onstrate\, theoretically\, how active droplets might be harnessed to overc
 ome this challenge. Active droplets are produced along the microchannel wa
 ll via stimulation of a responsive hydrogel\, and the ensuing phoretic sli
 p flows drive transport and mixing in the microfluidic device.
LOCATION:MR12
END:VEVENT
END:VCALENDAR