BTU overview
Faculty 1
Chair of Applied physics / sensor technology Prof. Dr. rer. nat. habil. Dieter Schmeißer

We are working on the following key aspects

  • Functionalization of the polymers
  • Applicability of the polymers
  • Sensitivity
  • Dependence of the sensitivity on the polymer thickness
  • Temperature dependence
  • Humidity dependence
  • repeatability
  • long term measurements
  • Simulation of exceeding of MAK values
  • Usability of different resonance circuits
  • Development of polymeric elctrodes

Literature

  • R. Zhou, D. Schmeißer and W. Göpel: Sensors and Actuators B 33 (1996) 188-193
  • G. Sauerbrey: Z. Phys. 155 (1959) 206.
  • A. Oprea, K. Henkel, R. Oehmgen, G. Appel, D. Schmeißer: Increased sensor sensitivities obtained by polymer coated quartz microbalances.   Materials Science and Engineering C8-9(1999) 509-512.
  • D. Schmeißer, G. Appel, A. Yfantis, W. Göpel: Highly conductive polypyrrole films on nonconductive substrates.   Synthetic Metals 83 (1996) 197.
  • G. Appel, R. Mikalo, K. Henkel, A. Oprea, A. Yfantis, I. Paloumpa: D. Schmeißer: Polymeric Electrodes.    Solid-State Electronics 44 (2000) 855-861.
  • K. Henkel, A. Oprea, I. Paloumpa, G. Appel, D. Schmeißer, P. Kamieth: Selective polypyrrole electrodes for quartz micro balances:    NO2 and gas flux sensitivities. Sensors and Actuators B 76/1-3 (2001) 124-129.
  • K. Henkel, I. Paloumpa, A. Oprea, G. Appel, D. Schmeißer, W. Frandsen, M. Schölzel: Entwicklung von Sensoren mit Elektroden aus leitfähigen   Polymeren, Teilbericht 16SV335/7 im Gemeinsamen Abschlußbericht zum Verbundprojekt Sensoren mit mikrostrukturierten Elektroden aus    leitfähigen Polymeren. Bekleidungsphysiologisches Institut Hohenstein e.V., Schloss Hohenstein,D-74357 Boennigheim,März 2000

We acknowledge the Federal Minister of Education, Science, Research and Technology (BMBF) for the financial support (16SV3357 "Polymelek")

Gas Sensors

Fig. 1 Gas mixing station and signal aquisition unit

Basics

Fig. 2 schematic of polymer coated quartz
dL : polymer layer thickness ; p : pressure ; T : absolute temperature ; MM : molar mass of the carrying gas; C : relative concentration of the test gas within the carying gas; AL : Area of the Electrode; kB : Boltzmann-Constant ; NA : Avogadro-Constant ; K : Ratio between concentration of the test gas in the polymer layer and the test gas itself

Measurement Set-up

Fig. 3 schematic of the gas mixing station and the data auisition unit

Typical Measurement

Fig. 4 Sensitivity of a PTDMS coated quartz microbalnce (d~7 kHz initial frequency shift due to the polymer deposition) at 25 °C