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So, boiling of water is an
incredibly useful process.
It allows us to move a lot of
heat very effectively and you
often see it in many different
industries. In fact most of the
worlds electricity comes from
power plants that run some sort
of steam cycle. But the way in
which water boils is basically
controlled by the formation of
these bubbles. And we've never
had great control of how these
bubbles are generated.
And what we've been trying
to do is in fact change this
boiling process in a way such
such that we can maximize the
efficiency of the system or
improve the heat transfer
performance. So what we can do
here is use these surfactant
molecules which are commonly
known as detergents, essentially.
And what we do here is by
applying an electric field we
can allow these surfactant
molecules to absorb to the
surface. And in this process
of having these molecules on
the surface, you can initiate
the boiling process and have
bubbles form. And now when you
now change the polarity of the
field or reduce the field in a
way, then you can in fact allow
these surfactant molecules to
move away from the surface
and turn off the bubble
generation process.
Fundamentally we've never
really thought about boiling
in this way, where it is sort of
a controllable process. The
analogy I like to use is the
electrical resistor. Boiling is
basically like an electrical
resistance that resistance never
changes. However what we've
done is we've kind of created a
transistor in a way where we
can change the thermal
resistance on the fly. And so
this process we've always
thought of as this very passive
process of just moving energy
across a thermal resistance is
fundamentally different now.
With our approach what we're
able to do is be able to
modulate the ability to improve
the efficiency or the
performance of these systems
on demand. We can control the
steam output. We can control the
temperature. And perhaps there
are a lot of applications that
we just haven't even thought of
in terms of energy and moving
heat that we could now do if we
have something that acts more
like a thermal transistor.