1. Instituto de Engenharia de Sistemas E Computadores–Microsistemas e Nanotecnologias (INESC MN) and IN–Institute of Nanoscience and Nanotechnology, Rua Alves Redol, 9, 1000-029 Lisbon, Portugal
2. Department of Bioengineering, Instituto Superior Técnico, University of Lisbon, 1049-001, Lisbon, Portugal