A Single-Pulse Actuated Micro Flow Sensor With Thermal Feedback and Digitally Controlled Power Distribution

In this work, we present a single-pulse-driven micro flow sensor that features a wide measurable range, extended linearity, and fast response, which was realized by the synergistic integration of thermal feedback and digitally controlled power distribution across dual microheaters. Employing a comprehensive computational fluid dynamics (CFD) modeling approach, we have developed and validated a sensor architecture capable of measuring nitrogen flow velocities across an exceptionally wide range (>26.6m/s). The CMOS-MEMS fabricated device utilizes poly-silicon thermosensitive elements with an optimized heater-detector spacing of 3 μm. Experimental results demonstrate a high sensitivity of 1.9 %/(m/s) across flow rates ranging from 0 to 26.66 m/s, with excellent linearity (R2= 0.99, obtained from least-squares regression) maintained within 0~4.44 m/s. Besides, the proposed system achieves a breakthrough thermal response time of 0.36 s, which is a 22× improvement over the previous dual-pulse TF-based designs. These advancements establish a new paradigm for high-performance flow sensing in dynamic environments, combining wide measurement range, excellent linearity, and rapid response in a single integrated platform.