1. Singapore Centre for 3D PrintingSchool of Mechanical and Aerospace EngineeringNanyang Technological University (NTU) 50 Nanyang Avenue Singapore 639798 Singapore
2. School of Materials Science and EngineeringNanyang Technological University (NTU) 50 Nanyang Avenue Singapore 639798 Singapore
3. Center for Energy Materials ResearchKorea Institute of Science and Technology (KIST) Seoul 02792 Republic of Korea