Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2013-04-01

Journal: JOURNAL OF MICRO-NANOLITHOGRAPHY MEMS AND MOEMS

Included Journals: SCIE

Volume: 12

Issue: 2

ISSN: 1932-5150

Key Words: electrospray ionization mass spectrometry; air amplifier; microelectromechanical systems; ANSYS; polydimethylsiloxane

Abstract: Recent developments in electrospray ionization mass spectrometry (ESI-MS) show that air amplifiers can be utilized to significantly enhance droplet desolvation and to focus gas-phase ions when provided between an electrospray (ES) source and the mass spectrometer (MS). However, these devices are bulky and expensive, which may be a factor prohibiting their broader utilization. We have developed a simple but effective method based on Bernoulli's principle, the Coanda effect and MEMS processing to focus electrosprayed droplets and liberated gas-phase ions. We demonstrate a computer simulation and fabrication process for a micromachined air amplifier. The simulation results are used to optimize the geometry and to meet performance requirements. The optimized results then provide a design guideline for the device's fabrication. The air amplifier is formed from two bonded polydimethylsiloxane (PDMS) casts. Each PDMS cast is fabricated through a molding process using a micromachined two-layer SU-8 mold. Experimental results show a 30-fold improvement in the ES current for certain operation conditions while the air amplifier is incorporated in the nano-electrospray ionization (nano-ESI) process. Compared with traditional air amplifiers, the microelectro-mechanical systems (MEMS) based air amplifier provides good performance while keeping the fabrication process simple and cost effective. (C) 2013 Society of Photo-Optical Instrumentation Engineers (SPIE)