A5091525557- Advanced MEMS and NEMS Technologies
- Mechanical and Optical Resonators
- Acoustic Wave Resonator Technologies
- Geophysics and Sensor Technology
- Force Microscopy Techniques and Applications
- Advanced Fiber Optic Sensors
- Photonic and Optical Devices
- Microfluidic and Bio-sensing Technologies
- Piezoelectric Actuators and Control
- Advanced Surface Polishing Techniques
- 3D IC and TSV technologies
- Inertial Sensor and Navigation
- Magneto-Optical Properties and Applications
- Advanced Sensor and Energy Harvesting Materials
- Advanced biosensing and bioanalysis techniques
- Plasma Diagnostics and Applications
- Advanced Measurement and Metrology Techniques
- Adhesion, Friction, and Surface Interactions
- Structural Health Monitoring Techniques
- Modular Robots and Swarm Intelligence
- Nanopore and Nanochannel Transport Studies
- Microbial Inactivation Methods
- Magnetic Field Sensors Techniques
- Icing and De-icing Technologies
- 2D Materials and Applications
Northwestern Polytechnical University
2014-2024
Ministry of Education of the People's Republic of China
2014-2019
This paper proposes and verifies a structure for the isolation of packaging stress in silicon-on-insulator-based microelectromechanical systems devices. The packaging-stress resides on handle layer consists circular disk, eight elastic beams, support frame. disk is located center die occupies less than 5% handle-layer area; this can reduce avoid uneven distribution. beams are L-shaped symmetrically distributed to decouple deformation from frame suppress evenly. in-plane out-of-plane induced...
Abstract Conventional electroporation approaches show limitations in the delivery of macromolecules vitro and vivo. These include low efficiency, noticeable cell damage nonuniform cells. Here, we present a simple 3D platform that enables massively parallel single-cell manipulation intracellular small molecules. A pyramid pit micropore array chip was fabricated based on silicon wet-etching method. controllable vacuum system adopted to trap single each micropore. Using this chip, safe...
The genetic heterogeneities in cancer cells pose challenges to achieving precise drug treatment a widely applicable manner. Most single-cell gene analysis methods rely on cell lysis for extraction and identification, showing limited capacity provide the correlation of properties real-time cellular behaviors. Here, we report single living nanoplatform that enables interrogating resistance millions cells. We designed Domino-probe identify intracellular target RNAs while releasing 10-fold...
This paper outlines the design of a novel mode-localized electric current sensor based on mechanically sensitive element weakly coupled resonator systems. With advantage high voltage sensitivity systems, under test is converted to via silicon shunt resistor, which causes stiffness perturbation one resonator. The mode-localization phenomenon alters energy distribution in system. A theoretical model sensing established, and performance determined: 567/A, noise floor 69.3 nA/√Hz, resolution...
Influences of the feedthrough capacitance on weakly coupled micromechanical resonators are theoretically analyzed and experimentally observed using current vector analysis Nyquist plots method for first time. By analyzing equivalent electric model with capacitance, it is found that existence will lead to frequency asynchronization measurement error amplitude ratio mode localization based sensors. The variations transmission responses influence demonstrated. became less than 2.3 ppm, down...
This paper describes a novel MEMS resonant accelerometer based on two weakly coupled resonators (WCRs) using the phenomenon of mode localization. To best authors' knowledge, it is first time that this principle experimentally demonstrated for an accelerometer. When acceleration acts proof masses, there will be differential electrostatic stiffness perturbation introduced WCRs, which leads to localization and shape change. Therefore, can sensed by measuring amplitude ratio shift. The measured...
Lower stiffness can improve the performance of capacitive-based microelectromechanical systems sensors. In this paper, softened beams, achieved by electrostatic assembly approach, are proposed to lower a capacitive MEMS accelerometer. The experiments show that accelerometer is reduced 43% with beams and sensitivity increased 72.6%. As result, noise 26.2 μg/√Hz an improvement 44.5%, bias instability 5.05 μg enhancement 38.7%. assembly-based softening technique proven be effective used in many...
This paper characterizes the sensitivity of a time domain MEMS accelerometer. The is defined by increment in measured interval per gravitational acceleration. Two sensitivities exist, and they can be enhanced decreasing amplitude frequency. with minor nonlinearity chosen to evaluate sensor. experimental results developed accelerometer demonstrate that span from −68.91 μs/g −124.96 1σ noises 8.59 mg 6.2 (amplitude 626 nm: 10.21 mg; 455 −94.51 7.76 342 6.23 mg), which indicates bigger...
This paper establishes a bias contribution model for micromachined Coriolis vibratory gyroscope (MCVG). Eight sources, including stiffness imbalance, mass and oscillation of the sense mode itself with their contributions, were analyzed calculated. The calculation methods key parameters, such as coupling stiffness, damping, offsets center based on established process imperfection model, are presented in detail. Finally, total MCVG is measured an error 18% compared theoretically calculated...
This paper theoretically and experimentally demonstrates the temperature drift suppression capability of a mode-localized accelerometer based on three degree freedom weakly coupled resonators. The theoretical model characteristics amplitude ratio frequency under influence Young's modulus were established. effect input conversion mechanism resonators are both included in model. simulation results show that thermal stress is main factor affecting output metric with mechanical coupling beam...
A simple, low-cost and reliable dicing-free silicon-on-insulator (SOI) process is presented for solving three major challenges in manufacturing the microelectromechanical systems devices, i.e. stiction, notching dicing damage. In this process, cavity used patterned on handle layer to solve stiction problem, exposed oxide removed hydrofluoric acid (HF) solution before deep reactive ion etching (DRIE) structure eliminate effect's impact. The dies are attached temporally a designed frame by...
The tunable coupling structure is proved to be an effective way improve the adjustability of sensitivity mode-localized sensors. However, non-linearity introduced by electrical brings difficulties its practical application. In this paper, a mechanical adjustment method proposed with lower output amplitude ratio and larger measurement range acceleration. accelerometer tested under closed-loop circuit obtain 37% 0.42% non-linearity. experimental results demonstrate 1.45/g initial over 40g...
In this work, we report a new design for an electrostatically actuated microgripper with post-assembly self-locking mechanism. The arms are driven by rotary comb actuators, enabling the to grip objects of any size from 0 100 μm. mechanism is elastic deformation energy and static electricity produce releasing actions. enables long periods without continuously applying external driving signal, which significantly reduces effects damage gripped caused these signals. was fabricated using...
Understanding the function of nanoscale structure morphology in ice adhesion properties is important deicing applications. The correlation between and nanowire as well corresponding shear fracture mechanism are presented for first time. Ice on nanowires was measured using a tangential ice-detaching instrument that developed in-house. Stress analysis performed COMSOL software. Nanowire surface shifted from Wenzel to Cassie transition wetting states when length increased. Tangential forces...
Electrostatic charge sensing is of fundamental significance for physical, chemical, and biological detection devices. Almost all current approaches with high resolution are based on single-electron tunneling transistor electrometers that must be operated under ultra-low temperature (<; 10 K) field-effect a dynamic range only several electrons. In this paper, micromachined resonant electrometer four-degrees-of-freedom weakly coupled resonators reported to realize room operation large...
This paper reports a high-resolution voltmeter based on applying mode localization in 3 DOF (degree of freedom) weakly coupled resonators (WCRs) system. When the input voltage is applied to electrode, stiffness perturbations are introduced into two outer resonators, leading drastic change shape owing phenomenon. Therefore, can be detected by measuring amplitude ratio shift WCRs. The theoretical model sensitivity established and detailed performances also given. measured relative (~12549112...
This paper presents a dicing-free process for silicon-on-insulator (SOI) microelectromechanical systems (MEMS). In the process, lag effect in deep reactive ion etching (DRIE) is used to form breaking trenches. backside DRIE, wide cavities are etched down buried oxide layer. The narrow trenches, contrast, not Therefore, trench can be break wafer after entire process; addition, handle layer still act as bracing structure before 'breaking'. Finally, device patterned, and DRIE step MEMS devices....
This paper reports a new design for an electrostatic actuated microgripper with ratchet self-locking mechanism. The mechanism enables long-time gripping without continuously applying the external driving signal, such as electrical, thermal or magnetic field, which significantly reduces effect and damage on gripped micro-scale objects that are induced by signals. is fabricated using silicon-on-insulator (SOI) wafer 30μm device layer. jaw gap 100 μm, locking interval 10 μm. A metal wire...
Exploring the integration of in-plane and out-of-plane accelerometers is a significant research focus, with primary challenge lying in development precise <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${Z}$ </tex-math></inline-formula> -axis accelerometer. Although mode localization has been successfully applied to accelerometers, its application remains challenging. This article presents innovative...