Design and Analysis of a Novel Microspeaker with Enhanced Low-Frequency SPL and Size Reduction

Abstract

In the era of multimedia devices, smartphones have become the primary device for consuming multimedia content. As technological developments have facilitated a more immersive multimedia experience, enlarged displays and the use of several sensors have limited the allowable size of microspeakers. Although sound plays an important role when consuming multimedia content, the limited space for microspeakers in modern devices leads to poor acoustic performance, especially at low frequencies. To address this issue, this paper proposes a novel microspeaker structure that enhances the low-frequency sound pressure level (SPL), while also featuring reduced exterior dimensions. The structure was designed and analyzed using 3D finite element analysis. Through coupling analysis, the simulation results were verified on the basis of the experimental results. The novel microspeaker has one outer magnet surrounding the entire coil, unlike in prototype microspeakers, which have two outer magnets. The gap between the top plates and coil is reduced, and a new type of coil is introduced for the purpose of increasing electromagnetic force. The samples were manufactured, and their SPLs were tested in an anechoic chamber. The experimental results prove that the proposed microspeaker offers an improved SPL at low frequencies compared with prototype microspeakers.

FEM‐Modeling of thermal and viscous effects in piezoelectric MEMS loudspeakers

“…The acoustic behavior of the MEMS loudspeakers depends on the solid structure, its material behavior and acoustic design [7]. To design and characterize PMEMS, various methods such as FEM and lumped element modeling are often applied [8,9]. Using low reduced frequency, Naderyan et al, [10] suggested an analytical solutions for modeling the thermoviscous damping in perforated MEMS.…”

Review of Recent Development of MEMS Speakers

“…Thus, the actuation method, structure, and electrode pattern design of the diaphragm as well as the enclosure design are crucial to the overall response and performance of a MEMS speaker. Both finite element analysis (FEA) and lumped element modelling (LEM) are typically employed to study the effects of various design parameters and to optimize the overall performance of MEMS speakers [ 19 , 20 ]. Several approaches in terms of material selection [ 12 ], special structural design [ 21 , 22 ], and electrode configuration [ 23 , 24 ] have also been demonstrated to achieve the better acoustic performance of MEMS speakers.…”