Center for Wireless Integrated MicroSensing and Systems (WIMS2), University of Michigan, Ann Arbor, MI 48109, USA.
Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109, USA.
Sensors (Basel). 2021 Jan 18;21(2):632. doi: 10.3390/s21020632.
This paper reports a multi-valve module with high chemical inertness and embedded flow heating for microscale gas chromatography (µGC) systems. The multi-valve module incorporates a monolithically microfabricated die stack, polyimide valve membranes, and solenoid actuators. The design incorporates three valves within a single module of volume 30.2 cm, which is suitable for the small form factor of µGC systems. The die stack uses fused silica wafers and polyimide valve membranes that enhance chemical inertness. The monolithic die stack requires only three lithographic masks to pattern fluidic microchannels, valve seats, and thin-film metal heaters and thermistors. The performance of fabricated multi-valve modules is compared to a commercial valve in tests using multiple volatile organic compounds, including alkanes, alcohols, ketones, aromatic hydrocarbons, and phosphonates. The valves show almost no distortion of chromatographic peaks. The experimentally measured ratio of flow conductance is 3.46 × 10, with 4.15 sccm/kPa in the open state and 0.0012 sccm/kPa in the closed state. The response time is <120 ms.
本文报道了一种具有高化学惰性和嵌入式流量加热功能的多阀模块，用于微尺度气相色谱（µGC）系统。该多阀模块集成了单片微加工的芯片堆叠、聚酰亚胺阀膜和电磁阀。该设计在单个模块体积为 30.2cm 的情况下集成了三个阀，适用于 µGC 系统的小外形尺寸。芯片堆叠使用熔融石英晶片和聚酰亚胺阀膜，增强了化学惰性。单片芯片堆叠仅需三个光刻掩模即可对微流道、阀座和薄膜金属加热器和热敏电阻进行图案化。使用多种挥发性有机化合物（包括烷烃、醇、酮、芳烃和膦酸盐）对制造的多阀模块进行测试，与商业阀的性能进行了比较。结果表明，这些阀几乎没有色谱峰的变形。实验测量的流量导纳比为 3.46×10，在开启状态下为 4.15sccm/kPa，在关闭状态下为 0.0012sccm/kPa。响应时间<120ms。
