A piezoelectric device comprising a continuous piezoelectric element (10) extending alternately back and forth to form a plurality of parallel, straight portions (14) arranged in a stack with intermediate linkage portions (15) at alternate ends of the straight portions (14). Each straight portion (14) is constructed and arranged with electrodes (12, 13) to bend, on activation, in the stacking direction in which the straight portions (14) are stacked with opposite curvature in two halves (16, 17) of the straight portion (14) to create displacement between the ends of the straight portion (14) in the stacking direction adding in series through the stack. The continuous nature of the piezoelectric element (10) eases manufacture. Devices with two types of construction are disclosed. Firstly, the continuous piezoelectric element (10) may have a bender construction such as a bimorph bender construction. Secondly, the continuous piezoelectric element (101) may be a sheet of piezoelectric material having overlapping slits (102) extending from alternate sides to form the straight portions (103) between the slits (102), with opposed electrodes (105) arranged on each major surface of the sheet in pairs separated across, and extending along, the straight portions (103).
