A microelectronic device, including at least one transistor including: on a substrate, a semiconductor zone with a channel zone covered with a gate dielectric zone, a mobile gate, suspended above the gate dielectric zone and separated from the gate dielectric zone by an empty space, which the gate is located at an adjustable distance from the gate dielectric zone, and a piezoelectric actuation device including a stack formed by at least one layer of piezoelectric material resting on a first biasing electrode, and a second biasing electrode resting on the piezoelectric material layer, wherein the gate is attached to the first biasing electrode and is in contact with the first biasing electrode, and the piezoelectric actuation device is configured to move the gate with respect to the channel zone.