Design, analysis and fabrication of a novel high-sensitivity, low-voltage MEMS microphone using an integrated arm diaphragm

Purpose This purpose of this study to propose a novel micro-electro-mechanical systems (MEMS) condenser microphone design that improves sensitivity while reducing pull-in voltage and power consumption, making it suitable for high-performance, low-power applications. Design/methodology/approach This design incorporates spiral arms as part of the diaphragm area to reduce diaphragm stiffness and enhance the microphone’s mechanical sensitivity. The microphone was modeled and analyzed to derive design equations and algorithms for various applications. A detailed design was created for smartphone applications with dimensions of 250 × 250 µm². Findings The proposed design resulted in a pull-in voltage of 1.62 V, mechanical sensitivity of 13.5 nm/Pa and a resonance frequency of 20 kHz. The fabricated microphone achieved a pull-in voltage of 1.81 V and a sensitivity of 12.23 mV/Pa, demonstrating a significant reduction in pull-in voltage and increased sensitivity compared with conventional MEMS microphones. Originality/value This microphone design, featuring a reduced pull-in voltage and improved sensitivity in a compact form, is distinct from traditional MEMS microphones. These advancements make it suitable for low-power, high-performance applications like smartphones and portable audio devices.