Wang Xiaowei, Zhang Zhijun, Zhang Wenqing, Su Tianyi, Zhang Shiwei
School of Mechanical Engineering and Automation, Northeastern University, Shenyang 110819, Liaoning, China.
Micromachines (Basel). 2020 Jun 28;11(7):634. doi: 10.3390/mi11070634.
Knudsen force generated by thermally driven gas flow in a microscale structure has been used for gas detection and has shown immeasurable potential in the field of microelectromechanical system (MEMS) gas sensors due to its novel sensing characteristics. In this article, the performances of three kinds of Knudsen force gas sensors with improved isosceles triangular shuttle arm structures were studied. In the first design, the top side and right side lengths were equal; in the second, the top side and bottom side lengths were equal; and for the third, the bottom side and right side lengths were equal. A detailed investigation including gas flow, thermal characteristics, Knudsen force, and coupling effects between the shuttle-heater pairs was conducted using the direct simulation Monte Carlo (DSMC) method and the main mechanisms for gas flow presented were almost the same in this work. However, the second design returned the highest Knudsen force performance. The value increased by 42.9% (P = 387 Pa) compared to the Knudsen force of the original square shuttle arm. The results also demonstrate that the coupling effects become weak toward the right with an increase in the number of shuttle-heater pairs.
由微尺度结构中热驱动气流产生的克努森力已被用于气体检测，并且由于其新颖的传感特性，在微机电系统（MEMS）气体传感器领域显示出不可估量的潜力。在本文中，研究了三种具有改进的等腰三角形穿梭臂结构的克努森力气体传感器的性能。在第一种设计中，顶边和右边长度相等；在第二种设计中，顶边和底边长度相等；在第三种设计中，底边和右边长度相等。使用直接模拟蒙特卡罗（DSMC）方法对气流、热特性、克努森力以及穿梭-加热器对之间的耦合效应进行了详细研究，并且在这项工作中所呈现的气流主要机制几乎相同。然而，第二种设计返回了最高的克努森力性能。与原始方形穿梭臂的克努森力相比，该值增加了42.9%（P = 387 Pa）。结果还表明，随着穿梭-加热器对数量的增加，耦合效应朝着右侧变弱。
