1. State Key Laboratory of Urban Water Resource and Environment
2. School of Environment
3. Harbin Institute of Technology
4. Harbin 150090
5. P. R. China
6. Innovative Center for Flexible Devices (iFLEX)
7. Max Planck – NTU Joint Lab for Artificial Senses
8. School of Materials Science and Engineering
9. Nanyang Technological University
10. 639798 Singapore