An electrical
relay array using conducting liquid in the switching mechanism. The
relay array is amenable to manufacture by micro-
machining techniques. Each element of the
relay array uses an
actuator, such as a piezoelectric element, to cause a switch
actuator to insert into a cavity in a static switch contact structure. The cavity has sides and a pad on its end that are wettable by the conducting liquid. The cavity is filled with the conducting liquid, which may be
liquid metal.
Insertion of the switch
actuator into the cavity causes the conducting liquid to be displaced outward and come in contact with the
contact pad on the switch actuator. The volume of conducting liquid is chosen so that when the actuator returns to its
rest position, the electrical contact is maintained by
surface tension and by
wetting of the contact pads on both the static switch contact structure and the actuator. When the switch actuator retracts away from the static switch contact structure, the
available volume for conducting liquid inside the fixed switch contact structure increases and the combination of the movement of the conducting liquid into the cavity and the
contact pad on the switch actuator moving away from the bulk of the conducting liquid causes the conducting liquid connection between the fixed and moving contact pads to be broken. When the switch actuator returns to its
rest position, the contact remains electrically open because there is not enough conducting liquid to bridge the gap without being disturbed. The
high frequency capability is provided by the additional conductors in the
assembly, which act to make the switch a coaxial structure.