At 10:00 am on June 8th, Professor Xie Huikai from Beijing Institute of Technology presented a report on the research progress of piezoelectric MEMS speakers. The lecture is hosted by Associate Professor Lu Yipeng from the School of Integrated Circuits. More than 30 people participated in total. At the beginning of the lecture, Professor Xie started with market data and used two representative manufacturers in the speaker field, Goethe Acoustics and Raytheon Acoustics, as examples. Through sector charts and bar charts of market share, he introduced the huge development potential of MEMS speakers, as well as their advantages in miniaturization, low power consumption, and large-scale production compared to traditional speakers. He listed two important indicators of MEMS speakers: maximum output sound pressure level (SPL) and total harmonic distortion (THD). Subsequently, Professor Xie provided a theoretical introduction on how to improve the maximum output sound pressure level of MEMS speakers from the perspectives of film displacement and frequency. He also conducted electrical modeling on four different principles of MEMS speakers, namely piezoelectric, electromagnetic, electrostatic, and thermoacoustic, from the perspective of lumped parameter models, and conducted theoretical analysis on key indicators. Then, Professor Xie discussed methods to improve the output sound pressure level of speakers from two perspectives: the selection of piezoelectric materials and the design of speaker structures. In addition, Professor Xie mentioned that there are two difficulties in the process of piezoelectric speakers based on PZT ceramics: first, how to accurately thin the PZT layer, especially when the thickness is less than 4 μ When m, it is necessary to consider issues such as thinning consistency and stress release; The second is how to corrode PZT thin layers. Currently, the corrosion scheme using HBF4 solution has a higher selectivity and faster corrosion rate. At the end of the report, the on-site attendees asked questions from the perspectives of nonlinear distortion, directional implementation, and the impact of packaging on performance. Professor Xie answered each question one by one, and also summarized how to further improve the performance of the speaker, providing prospects for the development of MEMS speakers.