A microfabricated microconcentrator for sensors and gas chromatography

Minhee Kim, Somenath Mitra

Research output: Contribution to journalArticlepeer-review

52 Scopus citations


The key component in trace analysis is the concentration step where the analytes are accumulated before the analysis. This paper presents the development of a micromachined microconcentrator that can be used to enhance the sensitivity of microsensors. Another application demonstrated here is a concentrator-injector for a gas chromatograph. The microconcentrators were fabricated on a 6-in. silicon substrate using standard photolithographic techniques (1 in.=2.54 cm). The channels were lined with a resistive layer, through which an electric current could be passed to cause ohmic heating. The preconcentration was done on a thin-film polymeric layer deposited above the heater in the channel. Rapid heating of the resistive layer caused the "desorption pulse" to be injected into the sensor, or onto a GC column. Due to their small size, the microconcentrators could be fabricated 20 to 50 (depending upon the size) at a time on a 6-in. silicon wafer. This paper presents the development and characterization of the microconcentrator. It was found that the microconcentrator performed well as a concentrator, and as an injector for GC. A 14-fold enrichment factor was achieved. The microconcentrator exhibited long-term stability in response, with typical relative standard deviation of between 3 and 5%.

Original languageEnglish (US)
Pages (from-to)1-11
Number of pages11
JournalJournal of Chromatography A
Issue number1-2
StatePublished - May 9 2003

All Science Journal Classification (ASJC) codes

  • Analytical Chemistry
  • Biochemistry
  • Organic Chemistry


  • Chip technology
  • Instrumentation
  • Microconcentrator
  • Sample handling


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