Department of Physics and Astronomy, University College London, London, United Kingdom.|Department of Physics, Northeastern University, Boston, Massachusetts, United States of America.|Department of Biomedical Engineering, Yale University, New Haven, Connecticut, United States of America.|Department of Biomedical Engineering, Yale University, New Haven, Connecticut, United States of America.|Department of Biomedical Engineering, Yale University, New Haven, Connecticut, United States of America.|Department of Physics and Astronomy, University College London, London, United Kingdom.