A micro-electromechanical actuator employs metal for the hot arm and silicon for at least the flexible portion of the cold arm. The cold arm made of silicon is coupled to a metal wire that moves with it and is used to carry the signal to be switched when at least two of such actuators are formed into a switch. Arrays of such switches on a first chip may be cooperatively arranged with a second chip that is flip-chip bonded to the first chip, the second chip having thereon wires routing the electrical control currents to the various hot arms for heating them as well as the signals to be switched by the various switches.