[1] Tokyo Metropolitan Univ, Dept Phys, Tokyo 1920397, Japan
[2] Natl Inst Adv Ind Sci & Technol, Nanomat Res Inst, Tsukuba 3058565, Japan
[3] Univ Tokyo, Dept Mech Engn, Tokyo 1138565, Japan
[4] Osaka Univ, Inst Sci & Ind Res, Osaka 5670047, Japan
[5] Zhejiang Univ, Sch Mech Engn, State Key Lab Fluid Power & Mechatron Syst, Hangzhou 310027, Peoples R China