1 Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, Ontario, M5S 3G8, Canada. xyliu@mie.utoronto.ca.
2 School of Mechanical Engineering & Automation, Beihang University, No. 37 Xueyuan Road, Beijing, 100191, China. s.luo@buaa.edu.cn.
3 Department of Mechanical Engineering, McGill University, 817 Sherbrooke Street West, Montreal, QC H3A 0C3, Canada.
4 Institute of Biomedical Engineering, University of Toronto, 164 College Street, Toronto, ON M5S 3G9, Canada.