2 research outputs found
Cytotoxicity of Gallium–Indium Liquid Metal in an Aqueous Environment
Eutectic gallium–indium alloy
(EGaIn) liquid metal is highly conductive, moldable, and extremely
deformable and has attracted significant attention for many applications,
ranging from stretchable electronics to drug delivery. Even though
EGaIn liquid metal is generally known to have low toxicity, the toxicity
of the metal, rather than a salt form of Ga or In, has not been systematically
studied yet. In this paper, we investigate the time-dependent concentration
of the ions released from EGaIn liquid metal in an aqueous environment
and their cytotoxicity to human cells. It is observed that only the
Ga ion is dominantly released from EGaIn when no external agitation
is applied, whereas the concentration of the In ion drastically increases
with sonication. The cytotoxicity study reveals that all human cells
tested are viable in the growth media with naturally released EGaIn
ions, but the cytotoxicity becomes significant with sonication-induced
EGaIn releasates. On the basis of the comparative study with other
representative toxic elements, that is, Hg and Cd, it could be concluded
that EGaIn is reasonably safe to use in an aqueous environment; however,
it should be cautiously handled when any mechanical agitation is applied
Influence of Water on the Interfacial Behavior of Gallium Liquid Metal Alloys
Eutectic
gallium indium (EGaIn) is a promising liquid metal for
a variety of electrical and optical applications that take advantage
of its soft and fluid properties. The presence of a rapidly forming
oxide skin on the surface of the metal causes it to stick to many
surfaces, which limits the ability to easily reconfigure its shape
on demand. This paper shows that water can provide an interfacial
slip layer between EGaIn and other surfaces, which allows the metal
to flow smoothly through capillaries and across surfaces without sticking.
Rheological and surface characterization shows that the presence of
water also changes the chemical composition of the oxide skin and
weakens its mechanical strength, although not enough to allow the
metal to flow freely in microchannels without the slip layer. The
slip layer provides new opportunities to control and actuate liquid
metal plugs in microchannelsî—¸including the use of continuous
electrowettingî—¸enabling new possibilities for shape reconfigurable
electronics, sensors, actuators, and antennas