1. Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark
2. The School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR, USA
3. Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, USA
4. Department of Functional Morphology and Biomechanics, Institute of Zoology, Kiel University, Kiel, Germany