This invention discloses a microswitch that is easy to assemble and manufacture. A second circuit is included for multiplying respective ones of the delayed signals by a corresponding coefficient and providing a respective intermediate signal in response thereto. This method includes actuating a means causing a pressure variation or an air flow within the suction-discharge device, positioning the lower free end of the device in such a way so that it becomes flush with a free surface of the biological sample, measuring an overpressure within the suction-discharge device, and sampling a quantity of the sample by suction using the device. in excess of 150 alternating layers, of high and low index of refraction material. Various features for improving the reliability and consistency of inflation of the containers are also disclosed. The reduction in the relative humidity to RHDRY is achieved by controlling the stoichiometry of the reactant flowfield and the temperature of the membrane electrode assembly such that the reduction to RHDRY decreases substantially continuously, relative to portions of the RH profile of the reactant flowfield prior to initiation of the stoichiometry-based control.