J. Ni et al., Electrochemically-actuated mercury valve for flow rate and direction control: design, characterization, and applications, J ELEC CHEM, 504(2), 2001, pp. 166-174
An electrochemically actuated mercury column was configured to function as
a valve for controlling both flow rate and flow direction. The valving mech
anism relies on a glass piston, which is placed on top of a mercury column,
to open or block a capillary how channel. The glass piston is actuated by
the movement of the mercury column, and is based on an electrochemically in
duced change in the surface tension at the mercury-electrolyte interface. T
he position of the piston can be controlled by applying different voltages
to the mercury electrode, which changes the surface tension of mercury, and
hence the relative height of the mercury column in each of the two arms of
a U-shaped tube. The extent of the piston displacement opens, closes, or p
artially opens the flow channel, thereby altering fluid flow rate. This pap
er presents the valving concept, and demonstrates its application in contro
lling both the rate and direction of fluid flow and in flow injection analy
ses. (C) 2001 Elsevier Science B.V. All rights reserved.