[1] Tsinghua Univ, Inst Microelect, Beijing, Peoples R China
[2] Chinese Acad Sci, Univ Chinese Acad Sci, Inst Phys, Beijing, Peoples R China
[3] Tsinghua Univ, Ctr Flexible Elect Technol, Beijing, Peoples R China
[4] Natl Inst Metrol NIM, Beijing, Peoples R China