1. School of Engineering and Applied Sciences Harvard University Cambridge MA 02138 USA
2. School of Mechanical Materials and Mechatronic Engineering University of Wollongong Wollongong NSW 2522 Australia
3. Intelligent Polymer Research Institute ARC Centre of Excellence for Electromaterials Science AIIM Facility University of Wollongong Wollongong NSW 2522 Australia
4. State Key Laboratory for Strength and Vibration of Mechanical Structures International Center for Applied Mechanics School of Aerospace Xi'an Jiaotong University Xi'an 710049 China
5. Soft Materials Group School of Chemistry University of Wollongong Wollongong NSW 2522 Australia
6. Kavli Institute for Bionano Science and Technology Harvard University Cambridge MA 02138 United States