Quasi-static/cyclic loading tests of nanometric SiO/sub 2/ wires using AFM technique for NEMS designs

T. Namazu1, T. Isono2
1Department of Mechanical and Intelligent Engineering, Faculty of Engineering, Himeji Institute of Technology, Himeji, Hyogo, Japan
2Department of Mechanical Engineering, Faculty of Science and Engineering, Ritsumeikan University, Kusatsu, Shiga, Japan

Tóm tắt

This research carried out intermediate temperature quasi-static/cyclic loading tests of nanometric silicon dioxide wires (SiO/sub 2/ nano-wires) using AFM, for revealing specimen size and temperature effects on mechanical properties and fatigue lives of the wires. Four kinds of the SiO/sub 2/ nano-wires with widths from 230 nm to 800 nm were prepared by a thermal oxidation of nanometric single crystal silicon wires (SCS nano-wires). Quasi-static bending tests using AFM examined Young's modulus, fracture stress and strain of the wires at temperatures ranging from 295 K to 573 K in high vacuum. All of the SiO/sub 2/ nano-wires fractured in a brittle manner at the test temperatures. Young's moduli of the nano-wires agreed with that of bulk silica, which showed that the modulus had no specimen size effect. However, fracture stress and strain of the SiO/sub 2/ nano-wires changed with not only temperature but also specimen size. Cyclic bending tests in AFM using the 230 nm- and 410 nm-wide SiO/sub 2/ wires investigated high cycle fatigue lives of the wires at room temperature. The number of cycles to failure of the 230 nm-wide wires was slightly larger than that of the 410 nm-wide wires at the loading frequency of 50 Hz and 450 Hz. This is suggestive of existing of the specimen size effect on the fatigue lives of the SiO/sub 2/ nano-wires.

Từ khóa

#Testing #Wires #Fatigue #Silicon compounds #Capacitive sensors #Mechanical factors #Oxidation #Thermal stresses #Temperature distribution #Frequency

Tài liệu tham khảo

tsuchiya, 2000, Tensile testing of insulating thin films; humidity effect on tensile strength of SiO2 films, Sensors and Actuators A, 82, 286, 10.1016/S0924-4247(99)00363-5 10.1109/TEI.1970.299088 10.1109/84.993447 10.1109/84.896765