1. Department of Physics, University of Otago, 730 Cumberland Street, Dunedin 9016, New Zealand
2. MacDiarmid Institute for Advanced Materials and Nanotechnology, 730 Cumberland Street, Dunedin 9016, New Zealand
3. Department of Mechanical & Manufacturing Engineering, Miami University, 56 Garland Hall, 650 East High Street, Oxford, Ohio 45056, United States