Acta Phys. -Chim. Sin. ›› 2010, Vol. 26 ›› Issue (05): 1355-1363.doi: 10.3866/PKU.WHXB20100508

• PHOTOCHEMISTRY AND SPECTROSCOPY • Previous Articles     Next Articles

Design and Fabrication of a Miniature FAIMS Sensor Chip

LI Hua, WANG Xiao-Hao, TANG Fei, ZHANG Liang, YANG Ji, LIN Tao, DING Li   

  1. State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments and Mechanology, Tsinghua University, Beijing 100084, P. R. China; School of Electronics and Computer Science and Technology, North University of China, Taiyuan 030051, P. R. China; 3Shimadzu Research Laboratory (Shanghai) Co., Ltd., Shanghai 201201, P. R. China
  • Received:2009-10-28 Revised:2010-01-26 Published:2010-04-29
  • Contact: TANG Fei E-mail:tangf@mail.tsinghua.edu.cn

Abstract:

Based on micro-electro-mechanical system (MEMS) technology, a miniature high-field asymmetric waveformion mobility spectrometry (FAIMS) sensor chip was designed and fabricated. The chip's dimensions are 18.8 mm×12.4 mm×1.2 mm. It consists of an ionization region, a drift tube, and an ion detection region. In the ionization region, the sample is ionized by a vacuum ultraviolet ion source at ambient pressure. The produced ions were then focused before entering the drift tube under the influence of the electrical field created by the focusing electrodes in the ionization region, which increased the ion signal intensity. A 200 μm thick silicon wafer was etched by inductively coupled plasma (ICP) and then bonded together with two glass plates sputtered with Au/Cr (300 nm/30 nm) to form a rectangular drift tube with dimensions of 10 mm×5 mm×0.2 mm. The ion detection region is a micro Faraday cup, which is made up of three rows of staggered cylinders of 200 μm in diameter and with a 100 μm spacing interval. The Faraday cup can detect positive and negative ions simultaneously. The FAIMS chip was investigated using high-field asymmetric rectangular waveform power with a peak voltage of 364 V at a frequency of 2 MHz and a duty cycle of 30%. Acetone and toluene samples were used to characterize the sensor chip. With a carrier gas flow rate of 80 L·h-1 and by sweeping the compensation voltage from -10 to 3 V at a 0.1 V steps, acetone and toluene spectra were obtained. The FAIMS-MS experiments further show that ions can be separated and filtered by the FAIMS system.

Key words: High-field asymmetric waveformion mobility spectrometry, Micro-electro-mechanical-system, High-filed asymmetric rectangular waveform, Micro faraday cup

MSC2000: 

  • O646