This study presents a barium titanate (BaTiO₃) film-based piezoelectric airflow sensor. This sensor integrated a piezoelectric beam array with a poly(dimethylsiloxane) orifice membrane as the core sensing component. The compact size of the micromachined device fit the requirements for a wearable device. The hydrothermally grown barium titanate film exhibited an orthorhombic crystal structure with good piezoelectric properties. We propose an algorithm to determine the airflow sensor performance using data from the measured piezoelectric signal and the displacement of the piezoelectric beam. This algorithm correlates the discharge coefficient of the core sensing component, Reynold’s number, airflow velocity, pressure difference across the component, displacement of the piezoelectric beam, strain of the barium titanate film, and generated charge from the sensor, which is rarely reported in the literature. The Young’s modulus and piezoelectric constant of the barium titanate film could also be derived as 100 GPa and 8 pC N⁻¹, respectively. Utilizing this algorithm and the generated piezoelectric signal of the sensor, important breath parameters of a young male subject at rest were monitored.

中文翻译：

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用于可穿戴呼吸监测应用的基于钛酸钡压电薄膜的光束阵列气流传感器

本研究提出了一种钛酸钡 (BaTiO ₃) 基于薄膜的压电气流传感器。该传感器集成了压电梁阵列和聚（二甲基硅氧烷）孔膜作为核心传感组件。微加工设备的紧凑尺寸符合可穿戴设备的要求。水热生长的钛酸钡薄膜呈现出具有良好压电性能的正交晶体结构。我们提出了一种算法，使用来自测量的压电信号和压电梁位移的数据来确定气流传感器的性能。该算法将核心传感组件的放电系数、雷诺数、气流速度、组件上的压差、压电梁的位移、钛酸钡薄膜的应变以及传感器产生的电荷相关联，这在文献中很少报道。钛酸钡薄膜的杨氏模量和压电常数也可以推导出为 100 GPa 和 8 pC N^-1，分别。利用该算法和传感器产生的压电信号，监测了一名年轻男性受试者在休息时的重要呼吸参数。