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A piezoelectric energy generator with a Deflection-limiting Circular Arc(DLCA) was presented to enhance its generated energy and reliability.The structure and working principle of the piezoelectric generator were introduced and an energy conversion model for the piezoelectric generator was established.By simulation,the influence of thickness ratio of the substrate thickness to the total thickness of the piezo-cantilever on the minimal radius of DLCA as well as the generated energy,and that of total thickness of the piezo-cantilever and the radius of DLCA on the generated voltage as well as electrical energy were obtained.The analytical results show that the minimal radius of the DLCA decreases linearly with the increasing of thickness ratio,and there is a shared optimal thickness ratio(0.35) for piezoelectric generators with different total thicknesses to achieve maximal output voltage and energy.Several piezoelectric generators with different radii of DLCA were fabricated and tested.The results show that the maximal voltage(displacement) of the piezoelectric generator depends mainly on the radii of DLCA.When a minimal radius of DLCA is set,both the maximal electrical energy and higher reliability can be achieved.

To increase frequency bands and the applicability in vibration environments,a piezoelectric generator consisted of multi-vibrators was presented.The output performance of the piezoelectric generator connected with vibrators in different methods(direct serial/parallel-connection,serial/parallel-connection with rectifiers) was studied theoretically and experimentally.The research results show that the piezoelectric generators connected with vibrators in serial/parallel through rectifiers achieves higher output voltages and wider frequency bands than those connected with vibrators directly.Moreover,the serial-connection piezoelectric generator takes advantages over the parallel-connection one in output voltages and frequency bands.A piezoelectric generator consisted of three cantilevers was fabricated and tested with the vibrators connected in different ways.With the output voltage beyond 10 V,the individual frequency bands of the three unconnected cantilevers are 143.1-148.1 Hz,160-166.2 Hz and 173.1-184.3 Hz,respectively.However,the total frequency band for output voltage beyond 10 V is extended to 141.8-190 Hz as the cantilevers are connected in serial with rectifiers.