scholarly journals The Asymmetric Flexure Hinge Structures and the Hybrid Excitation Methods for Piezoelectric Stick-Slip Actuators

2021 ◽  
Author(s):  
Tinghai Cheng ◽  
Xiaosong Zhang ◽  
Xiaohui Lu ◽  
Hengyu Li ◽  
Qi Gao ◽  
...  
Keyword(s):  
High Speed ◽  
Low Voltage ◽  
Mode Conversion ◽  
Resonant Mode ◽  
Superior Performance ◽  
Flexure Hinge ◽  
Asymmetric Structure ◽  
Stick Slip ◽  
Output Performance ◽  
Long Stroke

Piezoelectric stick–slip actuators have become viable candidates for precise positioning and precise metering due to simple structure and long stroke. To improve the performances of the piezoelectric stick–slip actuators, our team deeply studies the actuators from both structural designs and driving methods. In terms of structural designs, the trapezoid-type, asymmetrical flexure hinges and mode conversion piezoelectric stick–slip actuators are proposed to improve the velocity and load based on the asymmetric structure; besides, a piezoelectric stick–slip actuator with a coupled asymmetrical flexure hinge mechanism is also developed to achieve the bidirectional motion. In terms of driving methods, a non-resonant mode smooth driving method (SDM) based on ultrasonic friction reduction is first proposed to restrain the backward motion during the rapid contraction stage. Then, a resonant mode SDM is further developed to improve the output performance of the piezoelectric stick–slip actuator. On this basis, the low voltage and symmetry of the SDM are also discussed. Finally, the direction-guidance hybrid method (DGHM) excitation method is presented to achieve superior performance, especially for high speed.

scholarly journals A Novel Stick-Slip Nanopositioning Stage Integrated with a Flexure Hinge-Based Friction Force Adjusting Structure

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 765
Author(s):  
Junhui Zhu ◽  
Peng Pan ◽  
Yong Wang ◽  
Sen Gu ◽  
Rongan Zhai ◽  
...  
Keyword(s):  
Friction Force ◽  
High Speed ◽  
Simulation Analysis ◽  
Load Capacity ◽  
Dynamic Performance ◽  
Critical Role ◽  
Vertical Direction ◽  
Flexure Hinge ◽  
Stick Slip ◽  
Static Performance

The piezoelectrically-actuated stick-slip nanopositioning stage (PASSNS) has been applied extensively, and many designs of PASSNSs have been developed. The friction force between the stick-slip surfaces plays a critical role in successful movement of the stage, which influences the load capacity, dynamic performance, and positioning accuracy of the PASSNS. Toward solving the influence problems of friction force, this paper presents a novel stick-slip nanopositioning stage where the flexure hinge-based friction force adjusting unit was employed. Numerical analysis was conducted to estimate the static performance of the stage, a dynamic model was established, and simulation analysis was performed to study the dynamic performance of the stage. Further, a prototype was manufactured and a series of experiments were carried out to test the performance of the stage. The results show that the maximum forward and backward movement speeds of the stage are 1 and 0.7 mm/s, respectively, and the minimum forward and backward step displacements are approximately 11 and 12 nm, respectively. Compared to the step displacement under no working load, the forward and backward step displacements only increase by 6% and 8% with a working load of 20 g, respectively. And the load capacity of the PASSNS in the vertical direction is about 72 g. The experimental results confirm the feasibility of the proposed stage, and high accuracy, high speed, and good robustness to varying loads were achieved. These results demonstrate the great potential of the developed stage in many nanopositioning applications.

Piezoelectric stick-slip actuators with flexure hinge mechanisms: A review

2022 ◽  
pp. 1045389X2110722
Author(s):  
Guangda Qiao ◽  
Hengyu Li ◽  
Xiaohui Lu ◽  
Jianming Wen ◽  
Tinghai Cheng
Keyword(s):  
Load Capacity ◽  
Translational Motion ◽  
Structure Design ◽  
Flexure Hinge ◽  
Stick Slip ◽  
Positioning Accuracy ◽  
Output Performance ◽  
Analysis Methods ◽  
Working Principle ◽  
Improvement Scheme

Piezoelectric stick-slip actuators (PSSAs) are famous for ultimate working condition adaptability, simple structure, and positioning accuracy. To meet the demand of industrial application, lots of PSSAs designed with flexure hinge mechanisms (FHMs-PSSAs) have been developed to realize the requirements of translational motion, rotational motion, multi-degree-of-freedom (multi-DOF) motion. The output performance of the FHMs-PSSAs has been greatly improved, including load capacity, speed, and accuracy; moreover, some approaches to solve the problem of the backward motion are provided as well. In this work, the working principle of FHMs-PSSAs is introduced, and the excitation signals applicable to FHMs-PSSAs are summarized. Based on the current research and development status, the progress of structure design of FHMs-PSSAs is introduced in accordance with translatory FHMs-PSSAs, rotary FHMs-PSSAs, and multi-DOF FHMs-PSSAs. Additionally, the developed analysis methods and design schemes to improve the performance are introduced, including theoretical analysis methods, consistency scheme of forward and reverse performance, suppression scheme of the backward motion, and improvement scheme of positioning accuracy. The significance of this work can be regarded as a further supplement to the previous review articles on the PSSAs, which will provide a reference and guidance for the future development of FHMs-PSSAs.

AN EXPERIMENT WHICH MEASURES RESONANT MODE CONVERSION IN He II

1978 ◽  
Vol 39 (C6) ◽  
pp. C6-228-C6-229
Author(s):  
S. Garrett ◽  
S. Adams ◽  
S. Putterman ◽  
I. Rudnick
Keyword(s):  
Mode Conversion ◽  
Resonant Mode

scholarly journals Asymmetric Ge/SiGe coupled quantum well modulators

Nanophotonics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1765-1773
Author(s):  
Yi Zhang ◽  
Jianfeng Gao ◽  
Senbiao Qin ◽  
Ming Cheng ◽  
Kang Wang ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Quantum Well ◽  
Quantum Wells ◽  
High Speed ◽  
Low Voltage ◽  
Extinction Ratio ◽  
High Frequency Response ◽  
Modulation Format ◽  
Silicon Photonic ◽  
Coupled Quantum Well

Abstract We design and demonstrate an asymmetric Ge/SiGe coupled quantum well (CQW) waveguide modulator for both intensity and phase modulation with a low bias voltage in silicon photonic integration. The asymmetric CQWs consisting of two quantum wells with different widths are employed as the active region to enhance the electro-optical characteristics of the device by controlling the coupling of the wave functions. The fabricated device can realize 5 dB extinction ratio at 1446 nm and 1.4 × 10−3 electrorefractive index variation at 1530 nm with the associated modulation efficiency V π L π of 0.055 V cm under 1 V reverse bias. The 3 dB bandwidth for high frequency response is 27 GHz under 1 V bias and the energy consumption per bit is less than 100 fJ/bit. The proposed device offers a pathway towards a low voltage, low energy consumption, high speed and compact modulator for silicon photonic integrated devices, as well as opens possibilities for achieving advanced modulation format in a more compact and simple frame.

scholarly journals Reliability-Oriented Design of Inverter-Fed Low-Voltage Electrical Machines: Potential Solutions

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4144
Author(s):  
Yatai Ji ◽  
Paolo Giangrande ◽  
Vincenzo Madonna ◽  
Weiduo Zhao ◽  
Michael Galea
Keyword(s):  
Power Density ◽  
High Speed ◽  
High Performance ◽  
Low Voltage ◽  
Electrical Machines ◽  
Design Stage ◽  
Switching Frequency ◽  
Special Focus ◽  
Electrical Machine ◽  
Engineering Approach

Transportation electrification has kept pushing low-voltage inverter-fed electrical machines to reach a higher power density while guaranteeing appropriate reliability levels. Methods commonly adopted to boost power density (i.e., higher current density, faster switching frequency for high speed, and higher DC link voltage) will unavoidably increase the stress to the insulation system which leads to a decrease in reliability. Thus, a trade-off is required between power density and reliability during the machine design. Currently, it is a challenging task to evaluate reliability during the design stage and the over-engineering approach is applied. To solve this problem, physics of failure (POF) is introduced and its feasibility for electrical machine (EM) design is discussed through reviewing past work on insulation investigation. Then the special focus is given to partial discharge (PD) whose occurrence means the end-of-life of low-voltage EMs. The PD-free design methodology based on understanding the physics of PD is presented to substitute the over-engineering approach. Finally, a comprehensive reliability-oriented design (ROD) approach adopting POF and PD-free design strategy is given as a potential solution for reliable and high-performance inverter-fed low-voltage EM design.

scholarly journals Advanced Electrode Design for Low-Voltage High-Speed Thin-Film Lithium Niobate Modulators

2021 ◽  
Vol 13 (2) ◽  
pp. 1-9
Author(s):  
Xingrui Huang ◽  
Yang Liu ◽  
Zezheng Li ◽  
Huan Guan ◽  
Qingquan Wei ◽  
...  
Keyword(s):  
Thin Film ◽  
Lithium Niobate ◽  
High Speed ◽  
Low Voltage ◽  
Electrode Design

scholarly journals Investigation of PVT-Aware STT-MRAM Sensing Circuits for Low-VDD Scenario

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 551
Author(s):  
Zhongjian Bian ◽  
Xiaofeng Hong ◽  
Yanan Guo ◽  
Lirida Naviner ◽  
Wei Ge ◽  
...  
Keyword(s):  
Nonvolatile Memory ◽  
High Speed ◽  
Low Voltage ◽  
Supply Voltage ◽  
Random Access ◽  
Magnetic Tunnel Junction ◽  
Complementary Metal Oxide Semiconductor ◽  
Current Mode ◽  
Cmos Technology ◽  
Oxide Semiconductor

Spintronic based embedded magnetic random access memory (eMRAM) is becoming a foundry validated solution for the next-generation nonvolatile memory applications. The hybrid complementary metal-oxide-semiconductor (CMOS)/magnetic tunnel junction (MTJ) integration has been selected as a proper candidate for energy harvesting, area-constraint and energy-efficiency Internet of Things (IoT) systems-on-chips. Multi-VDD (low supply voltage) techniques were adopted to minimize energy dissipation in MRAM, at the cost of reduced writing/sensing speed and margin. Meanwhile, yield can be severely affected due to variations in process parameters. In this work, we conduct a thorough analysis of MRAM sensing margin and yield. We propose a current-mode sensing amplifier (CSA) named 1D high-sensing 1D margin, high 1D speed and 1D stability (HMSS-SA) with reconfigured reference path and pre-charge transistor. Process-voltage-temperature (PVT) aware analysis is performed based on an MTJ compact model and an industrial 28 nm CMOS technology, explicitly considering low-voltage (0.7 V), low tunneling magnetoresistance (TMR) (50%) and high temperature (85 °C) scenario as the worst sensing case. A case study takes a brief look at sensing circuits, which is applied to in-memory bit-wise computing. Simulation results indicate that the proposed high-sensing margin, high speed and stability sensing-sensing amplifier (HMSS-SA) achieves remarkable performance up to 2.5 GHz sensing frequency. At 0.65 V supply voltage, it can achieve 1 GHz operation frequency with only 0.3% failure rate.

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