Droplet
regulation
has
significant
application
potential
in
many
fields;
however,
conventional
controlling
methods
make
it
difficult
to
effectively
control
low
surface
tension
droplets.
Inspired
by
the
Leidenfrost
phenomenon,
a
pseudo-Leidenfrost
system
was
established
innovatively
through
micro-airflow
rather
than
evaporated
vapor
lift
droplet.
Both
experimental
and
numerical
studies
were
carried
out
investigate
effect
of
FC3283
(perfluorotripropylamine)
By
FC3283,
is
an
extremely
working
medium
with
thermal
stability
at
room
temperature.
The
oscillation
droplet
vertical
direction
analyzed
tracking
position
centroid.
velocity
pressure
distributions
bottom
droplet,
which
similar
revealed.
mechanical
analysis
period
analyzed.
Besides,
phenomenon
FC40
[FC-40
FluorinertTM
Electronic
Liquid]
droplets
various
Weber
number
investigated.
conditions
for
triggering
results
showed
that
motion
could
be
divided
into
three
stages:
falling,
hovering,
rising.
In
hovering
stage,
Laplace
force
played
important
role,
main
reason
rebound
while
role
aerodynamic
keep
on
gas
film.
had
influence
phenomenon:
small
tended
absorbed
micropores,
too
large
would
cause
suspend
or
even
leave.
This
study
helpful
laying
foundation
transportation
ACS Applied Materials & Interfaces,
Год журнала:
2023,
Номер
15(20), С. 24989 - 24998
Опубликована: Май 11, 2023
Versatile
surfaces
demonstrating
multiple
interfacial
functionalities
are
highly
demanded
as
a
surface
typically
serves
various
duties
and
faces
challenges
in
real
practice.
However,
such
versatile
rarely
reported
mainly
due
to
the
integrating
structural
characteristics.
Here,
by
mimicking
lotus
leaves,
butterfly
wing,
respiratory
cilia,
we
develop
termed
wire-on-pillar
magneto-responsive
superhydrophobic
arrays
(WP-MRSA),
which
possess
properties
of
superhydrophobicity,
anisotropicity,
stimuli
responsiveness,
flexibility.
By
combining
soft
lithography
self-alignment
iron-laden
aerosols
under
magnetic
field,
wires
planted
atop
prefabricated
pillar
arrays,
resulting
well-ordered,
sparse,
high-aspect-ratio,
flexible,
wires,
largely
deflect
response
field.
This
unique
integration
configurations
enables
functionalities,
on-demand
control
droplet
impact
dynamics,
real-time
regulation
lateral
adhesion
force,
fast
removal
sorting
objects,
precise
manipulation
droplets
for
selective
reactions.
Those
benefit
applications
especially
droplet-based
microfluidics
active
self-cleaning
surfaces.
The Journal of Physical Chemistry B,
Год журнала:
2024,
Номер
128(5), С. 1325 - 1331
Опубликована: Янв. 31, 2024
Magnetically
tuned
soft
machines
offer
great
promise
in
performing
a
wide
variety
of
programmable
tasks
via
their
dynamic
shape
adaptation
and
alteration.
Despite
dramatic
recent
advancements
this
regard,
selective
reconfiguration
the
wetting
behavior
ferrofluid
droplet
atop
hydrophobic
interface
adapted
as
magnetically
modulated
micromachine
remained
elusive
when
applied
field
intensity
exceeds
saturation
magnetization.
Here
we
unveil
strategy
to
unsettle
perspective
by
harnessing
magnetic
field-dependent
magnetization
phenomenon
that
may
be
exploited
exclusively
arrive
at
highly
controllable
switchable
states
droplets,
including
realization
ranges
contact
angles
for
given
field.
We
physical
law
from
resulting
interplay
forces
quantifies
time
dependence
angle
variation
Substantiated
experimental
findings,
our
multiphysics-based
simulations
further
evidence
possibilities
realizing
matter
over
range
parameters,
delving
into
principle.
Disrupting
established
notion
trivially
unique
governed
droplet-substrate
combination
alone,
paradigm
thus
benefit
practical
applications,
ranging
digital
microfluidics
recombination
chemistry.
We
experimentally
investigate
microliter-sized
water
droplet
impact
on
solid
and
hollow
square
micropillared
polydimethylsiloxane
substrates.
Micropillared
substrates
with
different
values
of
pitch
(34,
47,
62
μm)
hole
sizes
(0,
3,
6,
10
pillars
are
fabricated
using
soft
lithography
following
direct
laser
writer
maskless
photolithography.
observe
that
exhibit
increased
hydrophobicity
as
compared
to
the
Interestingly,
we
find
is
further
enhanced
size
increased.
To
understand
dynamics,
perform
high-speed
visualization
acquire
transient
evolution
impacting
droplets.
Based
velocity
(0.22–0.62
m/s),
pitch,
size,
identify
various
regimes,
namely,
non-bouncing,
partial
bouncing,
complete
bouncing.
At
a
given
value,
non-bouncing
bouncing
regimes
observed
for
substrates,
respectively.
substrate
exhibits
higher
capillary
pressure,
impalement
energy
barrier
associated
Cassie–Baxter
Wenzel
transition
toward
This
due
decrease
in
fraction
owing
incorporation
circular
holes
pillars.
The
analysis
shows
loss
viscous
dissipation
decreases
an
increase
which
enhances
fate
possibility.
fundamental
insights
gained
from
this
study
can
be
effectively
leveraged
by
modulating
surface
morphology
realize
desired
characteristics
potential
applications
such
self-cleaning
harvesting.
ACS Applied Materials & Interfaces,
Год журнала:
2024,
Номер
unknown
Опубликована: Окт. 3, 2024
Technologies
for
manipulating
droplets
have
applications
in
various
fields,
such
as
biomedical
devices,
chemical
engineering,
water
collection,
and
thermal
management.
The
morphology
of
magnetically
responsive
surfaces
are
modified
using
magnetic
fields
inducing
droplet
directional
rolling
bouncing.
Herein,
a
study
on
the
transport
is
reported,
identifying
three
movement
modes
analyzing
mechanisms
influencing
behavior.
explored
working
fluids
with
surface
tension
lower
than
that
water,
achieving
30%
ethanol
maximum
velocity
130
mm
s
The
dynamics
and
underlying
mechanisms
of
a
droplet
impacting
on
bubble
is
crucial
for
achieving
controllable
droplet-bubble
impacts.
In
this
study,
typical
modes
at
various
impact
velocities
were
observed
experimentally,
the
effects
release
height
(H0),
diameter
(Dd),
glycerol
content
(G)
in
solution
trajectory
(hd)
contact
time
(tc)
examined.
Furthermore,
critical
Weber
numbers
(Wecr)
heights
(H0cr)
between
different
predicted
through
energy
analysis.
results
indicate
that
five
outcomes
are
observed:
coalescence,
partial
rebound,
non-captured
penetration,
captured
penetration.
During
hd
increases
with
Dd
H0,
while
it
decreases
G.
addition,
film
oscillation
period
(τb)
introduced
to
measure
tc,
satisfying
tc1
>
τb/2
tc3
<
τb/4
Introducing
dimensionless
parameters—specifically
(WeI-II,
WeII-III,
WeIII-IV)
lie
penetration
penetration—to
classify
modes,
as
increases,
WeI-II
WeII-III
decrease
slowly,
whereas
WeIII-IV
rapidly.
Additionally,
increase
G,
shows
little
change
Based
balance
among
droplet's
initial
kinetic
(Ek0),
gravitational
potential
(Ep),
surface
increment
liquid
(ΔEs),
work
done
by
pressure
difference
(WΔp),
values
Wecr
H0cr
generally
match
well
experimental
results.
Advanced Materials Interfaces,
Год журнала:
2024,
Номер
unknown
Опубликована: Окт. 25, 2024
Abstract
Droplets
constitute
an
essential
discrete
form
of
liquids
and
are
prevalent
in
both
natural
industrial
fields.
Droplet
manipulation
technologies
have
broad
application
prospects
various
fields,
including
biomedical
devices,
chemical
engineering,
water
collection,
so
on.
The
surfaces
with
magnetic
responsiveness
has
emerged
as
a
pivotal
technique
droplet
control
owing
to
its
flexibility
precision
remote
operations.
In
this
study,
the
dynamic
rolling
behavior
low‐surface‐tension
working
fluids
droplets
on
superhydrophobic
magnetically
responsive
micropillar
array
(SMMA)
is
investigated,
focus
mechanisms
that
generate
instabilities
during
directional
motion
droplets.
factors
influencing
these
studied
using
data
analysis.
Moreover,
techniques
for
capturing
releasing
offering
significant
insights
into
efficient
handling
minute
amounts
experiments
automation
intricate
processes.
Langmuir,
Год журнала:
2023,
Номер
39(44), С. 15620 - 15629
Опубликована: Окт. 26, 2023
The
manipulation
of
droplet
movement
behavior
is
scientific
importance
and
has
practical
applications
in
many
fields,
such
as
biological
analysis,
water
collection,
oil-water
separation,
deicing,
antifrosting,
so
on.
Using
the
magneto-responsive
surface
to
dynamically
change
morphology
an
effective
method
realize
manipulation.
A
replica
molding
technique
was
used
fabricate
with
micropillar
array,
direction
array
could
be
changed
magnetic
induction
intensity.
mechanism
directional
rebound
on
implementation
controllability
were
investigated.
On
surface,
it
achievable
droplets
micrometer
scale.
critical
condition
for
identified.
force
energy
during
spreading
retraction
stages
analyzed,
which
lay
a
theoretical
foundation
precise
control
rebound.
