1. Laboratoire de Technologie des Composites et Polymères (LTC), Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland, Nestlé Research Center, Vers-Chez-Les-Blanc, 1000 Lausanne 26, Switzerland, and Zurich Research Laboratory, IBM Research GmbH, 8803 Rüschlikon, Switzerland