1. Institute of Photonics Technology Jinan University Guangzhou 510632 P. R. China
2. Singapore Centre for 3D Printing Nanyang Technological University 50 Nanyang Avenue Singapore 639798 Singapore
3. College of Materials Science and Technology Nanjing University of Aeronautics and Astronautics Nanjing 211100 P. R. China
4. Department of Chemistry Jinan University Guangzhou 510632 P. R. China
5. Department of Mechanical Engineering Korea Advanced Institute of Science and Technology (KAIST) Daejeon 34141 Republic of Korea
6. Institute of Advanced Materials (IAM) Nanjing Tech University (NanjingTech) Nanjing 211816 P. R. China