The effective piezoelectric transverse coefficient e(31,f) was measured on various lead zirconate-titanate (PZT) and aluminum nitride thin films. The measurement set-up is based on the collection of the electric charges created by the forced deflection of a Si cantilever coated with a piezoelectric material. The maximum value was obtained from a tetragonal composition of PZT (45/55 Zr/Ti ratio) and was equal to 8.3 C/m(2). The ALN layer exhibited 97% of the theoretical value calculated from single crystal data, i.e., e(31,f)- = 1.02 C/m(2) (C) 1999 Elsevier Science S.A. All rights reserved.