[1] Univ Freiburg, Dept Microsyst Engn, Electrochem Energy Syst, IMTEK, D-79110 Freiburg, Germany
[2] Univ Freiburg, Inst FIT Freiburg Ctr Interact Mat & Bioinspired T, D-79110 Freiburg, Germany
[3] Robert Bosch GmbH, Corp Res, D-71272 Renningen, Germany
[4] FPT Motorenforsch AG, CH-9320 Arbon, Switzerland
[5] Hahn Schickard, D-79110 Freiburg, Germany
[6] MTU Aero Engines AG, D-80995 Munich, Germany