1. Singapore Centre for 3D Printing, School of Mechanical and Aerospace Engineering Nanyang Technological University 50 Nanyang Avenue Singapore 639798 Singapore
2. Department of Mechanical Engineering, College of Design and Engineering National University of Singapore 9 Engineering Drive Singapore 117575 Singapore
3. School of Mechanical Engineering Georgia Institute of Technology Atlanta GA 30332 USA
4. Centre for Additive Manufacturing National University of Singapore Singapore 117602 Singapore