McCartney Mitchell M, Zrodnikov Yuriy, Fung Alexander G, LeVasseur Michael K, Pedersen Josephine M, Zamuruyev Konstantin O, Aksenov Alexander A, Kenyon Nicholas J, Davis Cristina E
Department of Internal Medicine, Division of Pulmonary and Critical Care Medicine, University of California, Davis , Sacramento, California 95617, United States.
ACS Sens. 2017 Aug 25;2(8):1167-1174. doi: 10.1021/acssensors.7b00289. Epub 2017 Aug 9.
We have developed a simple-to-manufacture microfabricated gas preconcentrator for MEMS-based chemical sensing applications. Cavities and microfluidic channels were created using a wet etch process with hydrofluoric acid, portions of which can be performed outside of a cleanroom, instead of the more common deep reactive ion etch process. The integrated heater and resistance temperature detectors (RTDs) were created with a photolithography-free technique enabled by laser etching. With only 28 V DC (0.1 A), a maximum heating rate of 17.6 °C/s was observed. Adsorption and desorption flow parameters were optimized to be 90 SCCM and 25 SCCM, respectively, for a multicomponent gas mixture. Under testing conditions using Tenax TA sorbent, the device was capable of measuring analytes down to 22 ppb with only a 2 min sample loading time using a gas chromatograph with a flame ionization detector. Two separate devices were compared by measuring the same chemical mixture; both devices yielded similar peak areas and widths (fwhm: 0.032-0.033 min), suggesting reproducibility between devices.
我们开发了一种易于制造的微型气体预浓缩器，用于基于微机电系统（MEMS）的化学传感应用。利用氢氟酸湿法蚀刻工艺制造出腔体和微流体通道，其中部分工艺可在洁净室外部进行，而非更常见的深反应离子蚀刻工艺。集成加热器和电阻温度探测器（RTD）采用激光蚀刻实现的无光刻技术制造。仅施加28 V直流电压（0.1 A）时，观察到最大加热速率为17.6℃/秒。对于多组分气体混合物，吸附和解吸流量参数分别优化为90标准立方厘米每分钟（SCCM）和25 SCCM。在使用Tenax TA吸附剂的测试条件下，该设备使用配有火焰离子化检测器的气相色谱仪，仅需2分钟的样品加载时间，就能检测低至22 ppb的分析物。通过测量相同的化学混合物对两个独立的设备进行比较；两个设备产生的峰面积和峰宽相似（半高宽：0.032 - 0.033分钟），表明设备之间具有可重复性。
