Showing papers by "Bei Peng published in 2021"
TL;DR: In this paper, the authors proposed an elaborate design to improve the mode match and Q value by positioning the supporting beams at the saddle points of the B 13 modal shape and introducing a buffering annular frame between beams and substrate.
Abstract: The ultrasonic motors (USM) based on microelectromechanical systems (MEMS) technology utilize the inverse piezoelectric effects to drive the rotor through the friction force to realize the torque output. Therefore, the generation of a stable traveling wave within the stator is a key to USM performance, which heavily depends on the quality factor ( Q ) and the mode match level of a stator resonator. The current ring stators of micromotor exhibited an apparent mode mismatch and a relatively low Q value due to the displacement constraints and anchor loss of supporting beams. This article, through the modal analysis and energy dissipation evaluation of stators, proposes an elaborate design to improve the mode match and Q value by positioning the supporting beams at the saddle points of the B 13 modal shape and introducing a buffering annular frame between beams and substrate. The designed stator has the natural frequency of 101.63 and 100.90 kHz and Q value of 89.5 obtained from the finite element method. And the prototype experiment shows the natural frequencies of two modes are 100.76 and 101.5 kHz, respectively, the maximum deflection of the stator under driving voltage of 0.5 and 1 V are 3.96 and 4.43 μ m, respectively, and the Q value is 84.58. Both the frequency and rotation tests indicate the proposed motor displays, a much higher Q , and extremely better mode match than current ones.
9 citations
TL;DR: In this paper, a set of mathematical procedures is introduced to process the basic elastic solutions (obtained by the method of Hankel transform, which was pioneered by Sneddon) and the solution of the dual integral equations.
Abstract: This work is a supplement to the work of Sneddon on axisymmetric Boussinesq problem in 1965 in which the distributions of interior-stress fields are derived here for a punch with general profile. A novel set of mathematical procedures is introduced to process the basic elastic solutions (obtained by the method of Hankel transform, which was pioneered by Sneddon) and the solution of the dual integral equations. These processes then enable us to not only derive the general relationship of indentation depth D and total load P that acts on the punch but also explicitly obtain the general analytical expressions of the stress fields beneath the surface of an isotropic elastic half-space. The usually known cases of punch profiles are reconsidered according to the general formulas derived in this study, and the deduced results are verified by comparing them with the classical results. Finally, these general formulas are also applied to evaluate the von Mises stresses for several new punch profiles.
3 citations
TL;DR: In this article, a curved film microstructure array fabricated through polydimethylsiloxane (PDMS) film buckling induced by mechanical stretching is presented, which can serve as microlens arrays with a focal length of 1010 μm.
Abstract: We report on curved film microstructure arrays fabricated through polydimethylsiloxane (PDMS) film buckling induced by mechanical stretching. In the process of the microstructure preparation, a PDMA film is glued on a bidirectionally prestretched PDMS sheet that has a square distributed hole array on its surface. After releasing the prestrain, the film microstructure array is created spontaneously. The fabricated microstructures possess a spherical surface and demonstrate very good uniformity. The film microstructure arrays can serve as microlens arrays with a focal length of 1010 μm. The microstructure formation mechanism is investigated via theoretical analysis and numerical simulation. The simulation results agree well with the experimental results. The prestrain applied by mechanical stretching during the fabrication has an important effect on the shape of the resulting film microstructures. The microstructure geometry can be easily tuned through controlling the applied prestrain.
2 citations
TL;DR: In this paper, a good fluid control tool in microfluidics and usually microelectrodes play important roles in such an approach such as generating a desired electric field, though the fabrication o...
Abstract: Electrokinetics is a good fluid control tool in microfluidics and usually microelectrodes play important roles in such approach such as generating a desired electric field. Though the fabrication o...