[1] Nanyang Technol Univ, HP NTU Digital Mfg Corp Lab, Singapore 639798, Singapore
[2] Chinese Acad Sci, Shanghai Inst Microsyst & Informat Technol, State Key Lab Transducer Technol, Shanghai 200050, Peoples R China
[3] Nanyang Technol Univ, Sch Elect & Elect Engn, Singapore 639798, Singapore
[4] Nanyang Technol Univ, Sch Mech & Aerosp Engn, Singapore 639798, Singapore