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Two kind of on-chip integrated fatigue bending test structures are designed through system-level simulation method based on macromodels to measure the fracture strength and fatigue mechanical properties of polysilicon thin films. The first on-chip fatigue test structure is actuated by V-beam thermal actuator, and the other test structure actuated by electrostatic comb. The static and dynamic analysis was performed by Coventorware Architect module using self-bulid reduced order model described with the MAST hardware language and some other commercial parts from Coventorware parts library. The structural dimension parameters are determined and optimized according to system-level simulation and the computing result has shown that the self-build macromodels and the on-chip integrated test system are efficient and reliable. Two kinds of polysilicon on-chip fatigue bending test structure were fabricated with two-layer polysilicon surface micromachining process in Institute of Microelectronics, Peking University.

The methods of on-chip integrated testing have a wide application with the development of the study for MEMS materials properties measurement in microscale. A novel on-chip integrated micro-tensile testing system is designed through system-level simulation based on macromodels to measure the fracture strength and fatigue mechanical properties of polysilicon thin films. The structure of testing instrument consists of V-beam electrothermal actuator, differential capacitance sensor, supporting spring and specimen. The capacitance signal is sensed and controlled by a second sigma-delta modulator circuit. The analytic macromodel of polysilicon thin film specimen considering geometric nonlinearity and the numerical reduced-order model of V-beam electrothermal actuator based on Krylov subspace projection are created separately and described in the MAST hardware language. The mechanical structure dimension size and circuit components parameters are determined and optimized according to system-level simulation. The computing result has shown that the self-build macromodels and the on-chip integrated test system are efficient and reliable.

Flight feather shaft of long-eared owl is characterized by a three-parameter model for linear viscoelastic solids to reveal its damping ability. Uniaxial tensile tests of the long-eared owl, pigeon, and golden eagle flight feather shaft specimens were carried out based on Instron 3345 single column material testing system, respectively, and viscoelastic response of their stress and strain was described by the standard linear solid model. Parameter fitting result obtained from the tensile tests shows that there is no significant difference in instantaneous elastic modulus for the three birds’ feather shafts, but the owl shaft has the highest viscosity, implying more obvious viscoelastic performance. Dynamic mechanical property was characterized based on the tensile testing results. Loss factor (tanδ) of the owl flight feather shaft was calculated to be 1.609 ± 0.238, far greater than those of the pigeon (0.896 ± 0.082) and golden eagle (1.087 ± 0.074). It is concluded that the long-eared owl flight feather has more outstanding damping ability compared to the pigeon and golden eagle flight feather shaft. Consequently, the long-eared owl flight feathers can dissipate the vibration energy more effectively during the flying process based on the principle of damping mechanism, for the purpose of vibration attenuation and structure radiated noise reduction.