ISBN 9783843908665

978-3-8439-0866-5, Reihe Mikrosystemtechnik

Régulo Miguel Ramírez Wong
Injector and Vacuum Pump in MEMS for a Micro Mass Spectrometer

147 Seiten, Dissertation Technische Universität Hamburg-Harburg (2012), Softcover, A5

Zusammenfassung / Abstract

The integration of the injection system in microsystems technologies reduced significantly the volume of the periphery of the PIMMS. With buried channels to drop the pres- sure down to a suitable range for the device, the robustness of the device was increased, as it is less sensitive to environmental impacts such as mechanical vibrations, impact or extreme temperatures. The manufacturing steps were also simplified, since no additional gluing of capillaries is necessary if a septum interface is used. This increases the yield of manufacturing and reduces fabrication costs. Also, the septum injection interface facilitates the replacement of chips if necessary, mak- ing the use of a complex device such as a mass spectrometer easier to handle for a user not specialized in analytical instruments. This would be the case for users in airport security and air quality controllers or technicians in the chemical industry. But the advantages are not only of practical nature, but also technical. The run time of the injection system was reduced from 25 seconds down to one second. This improve- ment allows monitoring of samples that change in time almost without delay and influences positively the applications and overall performance of the PIMMS as a mobile device.

The combination of the technology used for the integrated injection system contributed also to the development of an external module for a liquid sample injection system. A chip with a pressure drop stage allowed the drop of atmospheric pressure to a few Pascals to avoid re- condensation of the vapor-phase analyte. This technology was success- fully coupled to the PIMMS prototype. A disadvantage of the external module is the delay time, which is largely affected by the length of the tube connecting vaporizer and PIMMS. In the future, the integration of the liquid injection system is planned. For this, a vaporizer using microsystems technologies was developed and presented in this work. With a reduced power consumption of 0, 6 W, a vaporization rate suf- ficient for PIMMS, and high integration potential to the PIMMS due to the use of same fabrication technologies, it promises a closer step to the total integration of the periphery of a mobile mass spectrometer.