[1] Indiana Univ Purdue Univ, Dept Chem & Chem Biol, Indianapolis, IN 46260 USA
[2] Indiana Univ Purdue Univ, Dept Chem & Chem Biol, Indianapolis, IN 46202 USA
[3] Tech Univ Munich, Lehrstuhl Makromol Stoffe, D-85747 Garching, Germany
[4] Univ Freiburg, Inst Microsystemtechnol IMTEK Chem & Phys Interfa, Inst Microsystemtechnol, D-79110 Freiburg, Germany