1. Innovative Center for Flexible Devices (iFLEX) Max Planck – NTU Joint Lab for Artificial Senses School of Materials Science and Engineering Nanyang Technological University 50 Nanyang Avenue Singapore 639798 Singapore
2. Institute of Materials Research and Engineering Agency for Science, Technology and Research (A*STAR) 2 Fusionopolis Way, Innovis, #08‐03 Singapore 138634 Singapore
3. College of Chemical Engineering and Materials Science Quanzhou Normal University Quanzhou Fujian 362000 China