Disclosed is a thermo-mechanical actuator (100) comprising a piezo?electric module (110), the piezo-electric module comprising at least one piezo-electric element (120), wherein the thermo-mechanical actuator is configured to: o receive a thermal actuation signal (132) for controlling a thermal behaviour of the piezo-electric module, or o provide a thermal sensing signal (132) representative of a thermal state of the piezo-electric module, and, wherein the thermo-mechanical actuator is configured to: o receive a mechanical actuation (134) signal for controlling a mechanical behaviour of the piezo-electric module, or o provide a mechanical sensing signal (134) representative of a mechanical state of the piezo-electric module.

Disclosed is a thermo-mechanical actuator comprising a piezo-electric module, the piezo-electric module comprising at least one piezo-electric element, wherein the thermo-mechanical actuator is configured to receive a thermal actuation signal for controlling a thermal behaviour of the piezo-electric module, or provide a thermal sensing signal representative of a thermal state of the piezo-electric module. The thermo-mechanical actuator is configured to receive a mechanical actuation signal for controlling a mechanical behaviour of the piezo-electric module, or provide a mechanical sensing signal representative of a mechanical state of the piezo-electric module. And wherein the thermal actuation signal is configured to create a heat flux within the piezo-electric module and wherein the mechanical actuation signal is configured to deform the piezo-electric module.

A vibration type driving device includes an electro-mechanical energy conversion element; a vibrator fixed to the electro-mechanical energy conversion element and configured to be vibrated by application of voltage to the electro-mechanical energy conversion element; a first driven member and a second driven member frictionally driven by press-contact with the vibrator and configured to transmit rotational forces by frictional driving to an output shaft; and at least one pressing portion configured to bring the first driven member and the second driven member into press contact with the vibrator, wherein the pressing portion, the first driven member, the second driven member, and the vibrator are arranged to allow an air flow generated by an airflow generation unit to flow through an air-ventilation path of the pressing portion, between the first driven member and the second driven member, and an air-ventilation path of the vibrator.

A piezoelectric drive device includes: a piezoelectric vibrating portion including a vibrating body, a piezoelectric element disposed on at least one surface of the vibrating body, and a support portion supporting the vibrating body; an elastic member pressing the vibrating body against a driven member; and a heat conducting member disposed so as to be capable of changing a mutual positional relationship with the elastic member while maintaining a surface-to-surface contact state therewith.

A micromirror array comprises a substrate, a plurality of mirrors for reflecting incident light and, for each mirror of the plurality of mirrors, at least one multilayer piezoelectric actuator for displacing the mirror, wherein the at least one multilayer piezoelectric actuator is connected to the substrate, and wherein the at least one multilayer piezoelectric actuator comprises a plurality of piezoelectric layers of piezoelectric material interleaved with a plurality of electrode layers to form a stack of layers. Also disclosed is a method of forming such a micromirror array. The micromirror array may be used in a programmable illuminator. The programmable illuminator may be used in a lithographic apparatus and/or in an inspection and/or metrology apparatus.

A piezoelectric device includes a piezoelectric element, a mounting plate, an electronic element including a temperature sensor therein, a base on which the piezoelectric element is mounted with the mounting plate therebetween and on which the electronic element is mounted, and a lid joined to the base and hermetically sealing at least the piezoelectric element and the mounting plate.