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High-performance piezoelectric sensors play a crucial role in transduction and monitoring applications, and the piezoelectric performance of piezoelectric materials is affected by strain. Therefore, processing various microstructures on piezoelectric thin films by using a mask template method to cause stress concentration when they are subjected to force is a common method to improve their piezoelectric performance. However, the mask template method has disadvantages of low efficiency, low precision, complex template preparation, and high cost. Here, we demonstrate a simple and effective femtosecond laser direct writing method, and prepared adjustable size micro drum packaging, crater, groove, and other structures on the surface of Lead Zirconate Titanate (PZT) piezoelectric thin films, and detailed analysis of different structured thin film piezoelectric signal changes. The results show that compared with the unprocessed PZT thin film, there is no significant enhancement in the output voltage of the samples with the surface as groove and crater structures, and the output voltage of the sample with a bulge structure of 450 nm height is increased by about 30%. Theoretical analysis shows that this is due to a stress concentration phenomenon at the top of the bulge. In addition, we applied hydrophobic treatment to the film and the 450nm sample and tested the response of samples with different surface structures to water droplets of different volumes and falling frequencies. The research results show that both the film and the structured samples can well identify each droplet. Compared to the unprocessed PZT thin film, the 450 nm sample has stronger piezoelectric feedback to water droplets, and the feedback effect increases with the increase in droplet volume, and it can clearly identify the impact signal of a single droplet under higher frequency impact. This technology has potential application value in the field of rainfall monitoring.
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