Micromachines

Research

10 pages, 1820 KiB

Open AccessArticle

Fluorescence Properties of ZnOQDs-GO-g-C₃N₄ Nanocomposites

by Tianze Liu, Lei Wang, Ruxue Jiang, Yashi Tang, Yuxin He, Changze Sun, Yuguang Lv and Shuang Liu

Micromachines 2023, 14(4), 711; https://doi.org/10.3390/mi14040711 - 23 Mar 2023

Cited by 1 | Viewed by 1375

Abstract

In this paper, the fluorescence properties of ZnOQD-GO-g-C₃N₄ composite materials (ZCGQDs) were studied. Firstly, the addition of a silane coupling agent (APTES) in the synthesis process was explored, and it was found that the addition of 0.04 g·mL⁻¹ APTES [...] Read more.

In this paper, the fluorescence properties of ZnOQD-GO-g-C₃N₄ composite materials (ZCGQDs) were studied. Firstly, the addition of a silane coupling agent (APTES) in the synthesis process was explored, and it was found that the addition of 0.04 g·mL⁻¹ APTES had the largest relative fluorescence intensity and the highest quenching efficiency. The selectivity of ZCGQDs for metal ions was also investigated, and it was found that ZCGQDs showed good selectivity for Cu²⁺. ZCGQDs were optimally mixed with Cu²⁺ for 15 min. ZCGQDs also had good anti-interference capability toward Cu²⁺. There was a linear relationship between the concentration of Cu²⁺ and the fluorescence intensity of ZCGQDs in the range of 1~100 µM. The regression equation was found to be F₀/F = 0.9687 + 0.12343C. The detection limit of Cu²⁺ was about 1.74 μM. The quenching mechanism was also analyzed. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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12 pages, 4466 KiB

Open AccessArticle

Study on g-C₃N₄/BiVO₄ Binary Composite Photocatalytic Materials

by Pengfei Li, Yanqiu Hu, Di Lu, Jiang Wu and Yuguang Lv

Micromachines 2023, 14(3), 639; https://doi.org/10.3390/mi14030639 - 11 Mar 2023

Cited by 8 | Viewed by 2252

Abstract

Recent studies have shown that the composite of semiconductor photocatalytic materials and g-C₃N₄ can effectively inhibit photocatalytic carrier recombination and enhance the adsorption performance of the composite photocatalytic materials, so that the composite photocatalyst has stronger photocatalytic activity. In this [...] Read more.

Recent studies have shown that the composite of semiconductor photocatalytic materials and g-C₃N₄ can effectively inhibit photocatalytic carrier recombination and enhance the adsorption performance of the composite photocatalytic materials, so that the composite photocatalyst has stronger photocatalytic activity. In this paper, three kinds of graphitic carbon nitride photocatalyst g-C₃N₄ with different morphologies were prepared using the same precursor system by the chemical cracking method. After characterization and application, the sample with the most significant photocatalytic activity was selected and the g-C₃N₄/BiVO₄ heterostructure was synthesized by the simple solvent evaporation method, then the photocatalytic experiment was carried out. The results show that, when the content of BiVO₄ in the composite sample is 1%, the photocatalytic activity of RhB was the highest, and the degradation rate could reach 90.4%. The kinetic results showed that the degradation of RhB was consistent with the quasi-primary degradation kinetic model. The results of the photocatalytic cycle experiment show that the photocatalytic performance remains unchanged and stable after four photocatalytic cycles. The existence of a g-C₃N₄/BiVO₄ binary heterojunction was confirmed by UV/Visible diffuse reflection (UV-DRS) and photoluminescence (PL) experiments. Owing to the Z-type charge process between BiVO₄ and g-C₃N₄, efficient carrier separation was achieved, thus enhancing the photocatalytic capacity. This work provides a new idea for the study of heterojunction photocatalytic materials based on g-C₃N₄. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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10 pages, 5753 KiB

Open AccessArticle

A Novel Atomically Resolved Scanning Tunneling Microscope Capable of Working in Cryogen-Free Superconducting Magnet

by Tao Geng, Jihao Wang, Wenjie Meng, Jing Zhang, Qiyuan Feng, Yubin Hou and Qingyou Lu

Micromachines 2023, 14(3), 637; https://doi.org/10.3390/mi14030637 - 11 Mar 2023

Cited by 3 | Viewed by 2282

Abstract

We present a novel homebuilt scanning tunneling microscope (STM) with atomic resolution integrated into a cryogen-free superconducting magnet system with a variable temperature insert. The STM head is designed as a nested structure of double piezoelectric tubes (PTs), which are connected coaxially through [...] Read more.

We present a novel homebuilt scanning tunneling microscope (STM) with atomic resolution integrated into a cryogen-free superconducting magnet system with a variable temperature insert. The STM head is designed as a nested structure of double piezoelectric tubes (PTs), which are connected coaxially through a sapphire frame whose top has a sample stage. A single shaft made of tantalum, with the STM tip on top, is held firmly by a spring strip inside the internal PT. The external PT drives the shaft to the tip–sample junction based on the SpiderDrive principle, and the internal PT completes the subsequent scanning and imaging work. The STM head is simple, compact, and easy to assemble. The excellent performance of the device was demonstrated by obtaining atomic-resolution images of graphite and low drift rates of 30.2 pm/min and 41.4 pm/min in the X–Y plane and Z direction, respectively, at 300K. In addition, we cooled the sample to 1.6 K and took atomic-resolution images of graphite and NbSe₂. Finally, we performed a magnetic field sweep test from 0 T to 9 T at 70 K, obtaining distinct graphite images with atomic resolution under varying magnetic fields. These experiments show our newly developed STM’s high stability, vibration resistance, and immunity to high magnetic fields. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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15 pages, 5665 KiB

Open AccessArticle

Research on the Output Characteristics of Energy Conversion Elements under External Excitation

by Yun Zhang, Zonglin Xiao, Lan Liu, Wei Ren, Wei Liu, Yanjie Gou and Xiaoming Ren

Micromachines 2023, 14(3), 549; https://doi.org/10.3390/mi14030549 - 26 Feb 2023

Cited by 3 | Viewed by 1267

Abstract

Initiating explosive (IE) devices are widely used in the aerospace, resource mining, and basic industries and other fields. With the improvement in processing technology, IE devices are developing towards miniaturization and intelligence. As an important component of the energy conversion of IE devices, [...] Read more.

Initiating explosive (IE) devices are widely used in the aerospace, resource mining, and basic industries and other fields. With the improvement in processing technology, IE devices are developing towards miniaturization and intelligence. As an important component of the energy conversion of IE devices, the output characteristics of micro energy conversion (EC) elements directly affect the ignition performance of IE devices. Hence, this paper researches the output characteristics of EC elements under external excitation. Firstly, the fabrication process of the EC element is introduced, and the finite element analysis model of the temperature field is deduced. Secondly, the simulation model of the output characteristics of the EC element is constructed, the validity of the model is verified through experiments, and the basic characteristic parameters of the EC element are determined. Finally, four shapes of EC element structures are designed, the corresponding output characteristics under constant current excitation are analyzed, and the temperature and current field distributions of the EC elements with different shapes are given. The experimental and simulation results show the effectiveness of the analysis results in this paper, and the influence of different shapes on the insensitivity of EC elements is given through comparative analysis, which provides support for the design of micro structure EC elements. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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14 pages, 6009 KiB

Open AccessArticle

Research on Vibration Energy Harvester Based on Two-Dimensional Acoustic Black Hole

by Chunlai Yang, Yikai Yuan, Hai Wang, Ye Tang and Jingsong Gui

Micromachines 2023, 14(3), 538; https://doi.org/10.3390/mi14030538 - 25 Feb 2023

Cited by 3 | Viewed by 1548

Abstract

The wave energy focus effect of an acoustic black hole (ABH) is used for broadband vibration energy harvesting and boosts the harvested power. A vibration energy harvester based on two-dimensional ABH is proposed in this study, which consists of a rectangle plate with [...] Read more.

The wave energy focus effect of an acoustic black hole (ABH) is used for broadband vibration energy harvesting and boosts the harvested power. A vibration energy harvester based on two-dimensional ABH is proposed in this study, which consists of a rectangle plate with 2-D ABH and PZT film attached. The structure of ABH was designed and analyzed based on numerical simulation. The optimal parameters of the ABH were obtained, such as the power index, truncation thickness, cross-sectional length, and round table diameter, which were 3, 0.4 mm, 40 mm, and 24 mm, respectively. The quadratic velocity of the plate surface with ABH is up to 22.33 times that of a flat plate, and PZT film adheres to the corresponding positions of the ABH structure and plate structure, respectively. In the same condition, the average output power of a PZT with an ABH structure is higher than that of a flat plate under the same excitation-vibration condition. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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8 pages, 2063 KiB

Open AccessArticle

State Recognition of Multi-Nozzle Electrospinning Based on Image Processing

by Weiqi Gao, Jiaxin Jiang, Xiang Wang, Wenwang Li and Gaofeng Zheng

Micromachines 2023, 14(3), 529; https://doi.org/10.3390/mi14030529 - 24 Feb 2023

Cited by 1 | Viewed by 1947

Abstract

The online monitoring of a multi-jet electrospinning process is critical to the achievement of stable mass electrospinning for industrial applications. In this study, the construction of an ejection state recognition system of a multi-jet electrospinning process based on image processing is reported. The [...] Read more.

The online monitoring of a multi-jet electrospinning process is critical to the achievement of stable mass electrospinning for industrial applications. In this study, the construction of an ejection state recognition system of a multi-jet electrospinning process based on image processing is reported. The ejection behaviors regarding multi-nozzle electrospinning were recorded by CMOS industrial cameras in real time. The characteristic information regarding the multi-jet cone tip was obtained by processing the images regarding Roberts operator edge detection, Hough transform line detection, and mask histogram analysis. The jet anomalies of the hanging droplets in the nozzle outlet area could be obtained and identified by the vision. The identification accuracy towards the target hanging droplets was more than 85%. This work reports the intelligent control of large-scale multi-nozzle electrospinning equipment. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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8 pages, 3387 KiB

Open AccessArticle

Design and Test of a Spatial Nanopositioner for Evaluating the Out-of-Focus-Plane Performance of Micro-Vision

by Ruizhou Wang and Heng Wu

Micromachines 2023, 14(3), 513; https://doi.org/10.3390/mi14030513 - 22 Feb 2023

Cited by 2 | Viewed by 1136

Abstract

Micro-vision possesses high in-focus-plane motion tracking accuracy. Unfortunately, out-of-focus-plane displacements cannot be avoided, decreasing the in-focus-plane tracking accuracy of micro-vision. In this paper, a spatial nanopositioner is proposed to evaluate the out-of-focus-plane performance of a micro-vision system. A piezoelectric-actuated spatial multi-degree-of-freedom (multi-DOF) nanopositioner [...] Read more.

Micro-vision possesses high in-focus-plane motion tracking accuracy. Unfortunately, out-of-focus-plane displacements cannot be avoided, decreasing the in-focus-plane tracking accuracy of micro-vision. In this paper, a spatial nanopositioner is proposed to evaluate the out-of-focus-plane performance of a micro-vision system. A piezoelectric-actuated spatial multi-degree-of-freedom (multi-DOF) nanopositioner is introduced. Three in-plane Revolute-Revolute-Revolute-Revolute (RRRR) compliant parallel branched chains produce in-focus-plane motions. Three out-of-plane RRRR chains generate out-of-focus-plane motions. A typical micro-vision motion tracking algorithm is presented. A general grayscale template matching (GTM) approach is combined with the region of interest (ROI) method. The in-focus-plane motion tracking accuracy of the micro-vision system is tested. Different out-of-focus-plane displacements are generated using the proposed nanopositioner. The accuracy degradation of the in-focus-plane motion tracking is evaluated. The experimental results verify the evaluation ability of the proposed nanopositioner. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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9 pages, 3230 KiB

Open AccessArticle

Predictions of the Wettable Parameters of an Axisymmetric Large-Volume Droplet on a Microstructured Surface in Gravity

by Jian Dong, Jianliang Hu, Zihao Zhang, Mengying Gong and Zhixin Li

Micromachines 2023, 14(2), 484; https://doi.org/10.3390/mi14020484 - 19 Feb 2023

Cited by 1 | Viewed by 1467

Abstract

In this study, a numerical model was developed to predict the wettable parameters of an axisymmetric large-volume droplet on a microstructured surface in gravity. We defined a droplet with the Bond number

B_{o} > 0.1

as a large-volume droplet.

B_{o}

was [...] Read more.

In this study, a numerical model was developed to predict the wettable parameters of an axisymmetric large-volume droplet on a microstructured surface in gravity. We defined a droplet with the Bond number

B_{o} > 0.1

as a large-volume droplet.

B_{o}

was calculated by using the equation

B_{o} = \frac{ρ_{l} g}{γ_{lv}} {(\frac{3 V}{4 π})}^{\frac{2}{3}}

where

ρ_{l}

is the density of liquid,

γ_{lv}

is the liquid-vapor interfacial tension,

g

is the gravity acceleration and

V

is the droplet volume. The volume of a large-volume water droplet was larger than 2.7 μL. By using the total energy minimization and the arc differential method of the Bashforth–Adams equation, we got the profile, the apparent contact angle and the contact circle diameter of an axisymmetric large-volume droplet in gravity on a microstructured horizontal plane and the external spherical surface. The predictions of our model have a less than 3% error rate when compared to experiments. Our model is much more accurate than previous ellipsoidal models. In addition, our model calculates much more quickly than previous models because of the use of the arc differential method of the Bashforth–Adams equation. It shows promise for use in the design and fabrication of microfluidic devices. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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10 pages, 3313 KiB

Open AccessArticle

Effects of Electronic Irradiation on the Characteristics of the Silicon Magnetic Sensitive Transistor

by Zhipeng Yu, Xiaofeng Zhao, Weiwei Liu, Susu Li, Zijiang Yang, Dianzhong Wen and Hongquan Zhang

Micromachines 2023, 14(2), 430; https://doi.org/10.3390/mi14020430 - 11 Feb 2023

Viewed by 1258

Abstract

This work researched the effects of irradiation on the current-voltage characteristics and voltage magnetic sensitivity of the silicon magnetic sensitive transistor (SMST). The 1-MeV electron irradiation source was used to irradiate the SMST. The irradiation fluences were 1 × 10¹² e/cm² [...] Read more.

This work researched the effects of irradiation on the current-voltage characteristics and voltage magnetic sensitivity of the silicon magnetic sensitive transistor (SMST). The 1-MeV electron irradiation source was used to irradiate the SMST. The irradiation fluences were 1 × 10¹² e/cm², 1 × 10¹³ e/cm² and 1 × 10¹⁴ e/cm², respectively (the irradiation flux was 1 × 10¹⁰ cm⁻²·s⁻¹). The experimental results demonstrate that the collector current (I_C) of the SMST occurs attenuation after irradiation under the same collector voltage (V_CE) and the base current (I_B). The attenuated rate of the I_C increases obviously with the enhance of electron irradiation fluence when the I_B is the same. Moreover, the attenuated rate of the I_C increases slight with the rise of the I_B when the electron irradiation fluence is the same. When the supply voltage is 5.0 V (R_L = 1.5 kΩ) and the I_B is 4.0 mA, the voltage magnetic sensitivity (S_V) of the SMST occurs attenuate after irradiation. The attenuated rate of the S_V increases with the enhance of electron irradiation fluence. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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10 pages, 4449 KiB

Open AccessArticle

Highly Sensitive Magnetoelastic Biosensor for Alpha2-Macroglobulin Detection Based on MnFe₂O₄@chitosan/MWCNTs/PDMS Composite

by Xing Guo, Jianru Hou, Yang Ge, Dong Zhao, Shengbo Sang and Jianlong Ji

Micromachines 2023, 14(2), 401; https://doi.org/10.3390/mi14020401 - 7 Feb 2023

Cited by 2 | Viewed by 1722

Abstract

The need for Alpha2-Macroglobulin (α2-M) detection has increased because it plays an important role in the diagnosis of diabetic nephropathy (DN). However, few sensors can realize the high-sensitive detection for α2-M with characteristics of being fast, flexible, wearable and portable. Herein, a biosensor [...] Read more.

The need for Alpha2-Macroglobulin (α2-M) detection has increased because it plays an important role in the diagnosis of diabetic nephropathy (DN). However, few sensors can realize the high-sensitive detection for α2-M with characteristics of being fast, flexible, wearable and portable. Herein, a biosensor based on a MnFe₂O₄@chitosan/MWCNTs/PDMS composite film was developed for α2-M detection. Due to the excellent magnetoelastic effect of MnFe₂O₄ nanoparticles, the stress signal of the biosensor surface induced by the specific antibody–antigen binding was transformed into the electrical and magnetic signal. Chitosan-coated MnFe₂O₄ particles were used to provide biological modification sites for the α2-M antibody, which simplified the conventional biological functionalization modification process. The MnFe₂O₄@chitosan particles were successfully prepared by a chemical coprecipitation method and the property was studied by TEM, FT-IR and XRD. MWCNTs were employed to enhance electrical conductivity and the sensitivity of the biosensor. The detection limit (LOD) was reduced to 0.1299 ng·mL⁻¹ in the linear range from 10 ng∙mL⁻¹ to 100 µg·mL⁻¹, which was significantly lower than the limit of health diagnostics. The biosensor is fabricated by a simple method, with advantages of being rapid and highly-sensitive, and having selective detection of α2-M, which provides a novel method for the early diagnosis of DN, and it has potential in the point of care (PoC) field. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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11 pages, 3460 KiB

Open AccessArticle

Numerical Simulation of Motion and Distribution Characteristics for Electrospray Droplets

by Jiaxin Jiang, Zunxu Qian, Xiang Wang, Huatan Chen, Guoyi Kang, Yifang Liu, Gaofeng Zheng and Wenwang Li

Micromachines 2023, 14(2), 396; https://doi.org/10.3390/mi14020396 - 5 Feb 2023

Cited by 2 | Viewed by 1743

Abstract

Electrospray is a typical technology to prepare large amounts of droplets at micro/nano scale. Establishing the relationship between the processing parameters and the motion and distribution characteristics for electrospray droplets is an effective approach to guide the uniform deposition of the electrospray membrane. [...] Read more.

Electrospray is a typical technology to prepare large amounts of droplets at micro/nano scale. Establishing the relationship between the processing parameters and the motion and distribution characteristics for electrospray droplets is an effective approach to guide the uniform deposition of the electrospray membrane. In this paper, a dynamic model of electrospray droplets based on the fully resolved direct numerical simulation (FR-DNS) method was constructed, and the spatial motion behaviors of charged droplets were simulated. The coupling effect of electric field force, the charge repulsive force, and the gravity on the motion and distribution of electrospray droplets was studied, and the relationship between processing parameters including the applied voltage and distance from the nozzle to the collecting plate and the spatial distribution of charged droplets was clarified in a direct way. The simulation model provided a good approach for the quantitative description of the motion and distribution behaviors for electrospray droplets, which would help to guide the control of the electrospray jet ejection process. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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13 pages, 5558 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

A Cryostat Applicable to Long-Wavelength Light-Driven Scanning Probe Microscopy

by Kui Xiang, Caihong Xie, Qiyuan Feng, Ze Wang, Guangbin Dai, Jihao Wang, Jing Zhang, Wenjie Meng, Yubin Hou, Qingyou Lu and Yalin Lu

Micromachines 2023, 14(2), 378; https://doi.org/10.3390/mi14020378 - 2 Feb 2023

Cited by 1 | Viewed by 2027

Abstract

Recently, there has been growing interest in using lightwave-driven scanning probe microscopy (LD-SPM) to break through the Abbe diffraction limit of focusing, yielding insight into various energy couplings and conversion processes and revealing the internal information of matter. We describe a compact and [...] Read more.

Recently, there has been growing interest in using lightwave-driven scanning probe microscopy (LD-SPM) to break through the Abbe diffraction limit of focusing, yielding insight into various energy couplings and conversion processes and revealing the internal information of matter. We describe a compact and efficient optical cryostat designed for LD-SPM testing under magnetic fields. The exceptional multilayer radiation shielding insert (MRSI) forms an excellent temperature gradient when filled with heat conducting gas, which removes the requirement to install an optical window in the liquid helium cooling shell. This not only critically avoids the vibration and thermal drift caused by solid heat conduction but also minimizes light transmission loss. The application of gate valves and bellows allows a simpler and more effective replacement of the sample and working cell in the test cavity. ANSYS software is used for steady-state thermal analysis of the MRSI to obtain the temperature distribution and heat transfer rate, and the necessity of the flexible copper shielding strips is illustrated by the simulations. The topography and magnetic domain images of 45 nm-thick La_0.67Ca_0.33MnO₃ thin films on NdGaO₃(001) substrates under a magnetic field were obtained by a self-made lightwave-driven magnetic force microscope in this cryostat. The resolution and noise spectra during imaging reveal temperature stability and low vibration throughout the cryostat. The experience acquired during the development of this cryostat will help to establish cryostats of similar types for a variety of optic applications requiring the use of cryogenic temperatures. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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9 pages, 2571 KiB

Open AccessArticle

Atomic-Resolution Imaging of Micron-Sized Samples Realized by High Magnetic Field Scanning Tunneling Microscopy

by Weixuan Li, Jihao Wang, Jing Zhang, Wenjie Meng, Caihong Xie, Yubin Hou, Zhigang Xia and Qingyou Lu

Micromachines 2023, 14(2), 287; https://doi.org/10.3390/mi14020287 - 22 Jan 2023

Cited by 1 | Viewed by 2148

Abstract

Scanning tunneling microscopy (STM) can image material surfaces with atomic resolution, making it a useful tool in the areas of physics and materials. Many materials are synthesized at micron size, especially few-layer materials. Limited by their complex structure, very few STMs are capable [...] Read more.

Scanning tunneling microscopy (STM) can image material surfaces with atomic resolution, making it a useful tool in the areas of physics and materials. Many materials are synthesized at micron size, especially few-layer materials. Limited by their complex structure, very few STMs are capable of directly positioning and imaging a micron-sized sample with atomic resolution. Traditional STMs are designed to study the material behavior induced by temperature variation, while the physical properties induced by magnetic fields are rarely studied. In this paper, we present the design and construction of an atomic-resolution STM that can operate in a 9 T high magnetic field. More importantly, the homebuilt STM is capable of imaging micron-sized samples. The performance of the STM is demonstrated by high-quality atomic images obtained on a graphite surface, with low drift rates in the X–Y plane and Z direction. The atomic-resolution image obtained on a 32-μm graphite flake illustrates the new STM’s ability of positioning and imaging micron-sized samples. Finally, we present atomic resolution images at a magnetic field range from 0 T to 9 T. The above advantages make our STM a promising tool for investigating the quantum hall effect of micron-sized layered materials. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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11 pages, 2635 KiB

Open AccessArticle

Input–Output-Improved Reservoir Computing Based on Duffing Resonator Processing Dynamic Temperature Compensation for MEMS Resonant Accelerometer

by Xiaowei Guo, Wuhao Yang, Tianyi Zheng, Jie Sun, Xingyin Xiong, Zheng Wang and Xudong Zou

Micromachines 2023, 14(1), 161; https://doi.org/10.3390/mi14010161 - 8 Jan 2023

Cited by 6 | Viewed by 2204

Abstract

An MEMS resonant accelerometer is a temperature-sensitive device because temperature change affects the intrinsic resonant frequency of the inner silicon beam. Most classic temperature compensation methods, such as algorithm modeling and structure design, have large errors under rapid temperature changing due to the [...] Read more.

An MEMS resonant accelerometer is a temperature-sensitive device because temperature change affects the intrinsic resonant frequency of the inner silicon beam. Most classic temperature compensation methods, such as algorithm modeling and structure design, have large errors under rapid temperature changing due to the hysteresis of the temperature response of the accelerometer. To address this issue, we propose a novel reservoir computing (RC) structure based on a nonlinear silicon resonator, which is specifically improved for predicting dynamic information that is referred to as the input–output-improved reservoir computing (IOI-RC) algorithm. It combines the polynomial fitting with the RC on the input data mapping ensuring that the system always resides in the rich nonlinear state. Meanwhile, the output layer is also optimized by vector concatenation operation for higher memory capacity. Therefore, the new system has better performance in dynamic temperature compensation. In addition, the method is real-time, with easy hardware implementation that can be integrated with MEMS sensors. The experiment’s result showed a 93% improvement in IOI-RC compared to raw data in a temperature range of −20–60 °C. The study confirmed the feasibility of RC in realizing dynamic temperature compensation precisely, which provides a potential real-time online temperature compensation method and a sensor system with edge computing. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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10 pages, 4095 KiB

Open AccessArticle

A Readout Circuit for MEMS Gas Sensor

by Shengle Ren, Mingyuan Ren and Honghai Xu

Micromachines 2023, 14(1), 150; https://doi.org/10.3390/mi14010150 - 6 Jan 2023

Cited by 2 | Viewed by 2413

Abstract

In recent years, the application of gas sensors is becoming more and more extensive. Driven by potential applications such as the Internet of Things, its technology development direction begins with miniaturization, integration, modularization, and intelligence. However, there is a bottleneck in the research [...] Read more.

In recent years, the application of gas sensors is becoming more and more extensive. Driven by potential applications such as the Internet of Things, its technology development direction begins with miniaturization, integration, modularization, and intelligence. However, there is a bottleneck in the research of interface circuits, which restricts the development of gas sensors in volume, power consumption, and intelligence. To solve this problem, a MEMS gas sensor interface circuit based on ADC technology is proposed in this paper. Under the condition of the Huahong 110 nm process, the working voltage is 3.3 V, the resistance change of 100 Ω~1 MΩ can be detected, the conversion error is in the range of 0.5~1%, and the maximum power consumption is 986 μW. The overall layout area is 0.49 × 0.77 mm². Finally, the correctness of the circuit function is verified by post-layout simulation. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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8 pages, 2842 KiB

Open AccessArticle

A Novel Intelligent Rebound Hammer System Based on Internet of Things

by Zongqiang Pang, Qing Wang, Yong Wang and Zhiyin Gong

Micromachines 2023, 14(1), 148; https://doi.org/10.3390/mi14010148 - 6 Jan 2023

Cited by 1 | Viewed by 1818

Abstract

In order to improve the test efficiency of concrete strength and ensure measured data reliability, we present a novel intelligent rebound hammer system which is based on the Internet of Things (IoT) and speech recognition technology. The system uses a STM32F103C8T6 microcontroller as [...] Read more.

In order to improve the test efficiency of concrete strength and ensure measured data reliability, we present a novel intelligent rebound hammer system which is based on the Internet of Things (IoT) and speech recognition technology. The system uses a STM32F103C8T6 microcontroller as the Main Control Unit (MCU), and one BC26 module as the communication unit, combined with a LD3320 voice recognition module and TOF050H laser ranging sensor to achieve the function of phonetic transcription and laser ranging. Without the need for traditional multi-person collaboration and burdensome data transfer, the system can collect the data of rebound value and location information and send them to the remote cloud information management system automatically in real time. The test results show that the system has high measuring accuracy, good data transmission stability and convenient operation, which could provide guidance for other types of non-destructive testing equipment designs. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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9 pages, 3007 KiB

Open AccessArticle

Two-Terminal Nonvolatile Write-Once-Read-Many-Times Memory Based on All-Inorganic Halide Perovskite

by Zhipeng Yu, Xiaofeng Zhao, Chunpeng Ai, Xin Fang, Xiaohan Zhao, Yanchao Wang and Hongquan Zhang

Micromachines 2023, 14(1), 93; https://doi.org/10.3390/mi14010093 - 29 Dec 2022

Cited by 3 | Viewed by 1964

Abstract

Write-once-read-many-times (WORM) memory belonging to an important non-volatile memory type achieves the read-only state after the write operation and is used in the fields of data security storage widely. WORM memory has been developed based on a variety of materials. In recent years, [...] Read more.

Write-once-read-many-times (WORM) memory belonging to an important non-volatile memory type achieves the read-only state after the write operation and is used in the fields of data security storage widely. WORM memory has been developed based on a variety of materials. In recent years, halide perovskites have become the research hotspot material for this memory due to its excellent properties. Here, the all-inorganic CsPbBr₃ perovskite thin film was prepared on a FTO substrate by using a two-step method. The prepared CsPbBr₃ thin films have the characteristics of densely packed crystal grains and smooth surface. The device, having the FTO/CsPbBr₃/Al sandwich structure by evaporating the Al electrode onto the CsPbBr₃ thin film, represents the typical WORM behavior, with long data retention time (10⁴ s), a low operation voltage (2.1 V) and a low reading voltage (0.1 V). Additionally, the resistance transition mechanism of the resulting WORM devices was analyzed. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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16 pages, 6242 KiB

Open AccessArticle

Study on the Manipulation Strategy of Metallic Microstructures Based on Electrochemical-Assisted Method

by Dongjie Li, Mingrui Wang, Weibin Rong, Liu Yang, Donghao Xu and Yu Zhang

Micromachines 2022, 13(12), 2151; https://doi.org/10.3390/mi13122151 - 5 Dec 2022

Cited by 1 | Viewed by 1518

Abstract

Microcomponent manipulation (MCM) technology plays a decisive role in assembling complex systems at the micro- and nanoscale. However, the existing micromanipulation methods are difficult to widely apply in the manufacturing of microelectromechanical systems (MEMSs) due to the limited manipulation space and complex application [...] Read more.

Microcomponent manipulation (MCM) technology plays a decisive role in assembling complex systems at the micro- and nanoscale. However, the existing micromanipulation methods are difficult to widely apply in the manufacturing of microelectromechanical systems (MEMSs) due to the limited manipulation space and complex application objects, and the manipulation efficiency is relatively low, which makes it difficult to industrialize these micromanipulating systems. To solve the above problems, this paper proposes an efficient metal MCM strategy based on the electrochemical method. To verify the feasibility and repeatability of the strategy, the finite element model (FEM) incorporating the hydrodynamic and electrochemical theories is used to calculate the local stress distribution of the contact position during the dynamic pick-up process. Based on the simulation results, we defined the relationship between the parameters, such as the optimal manipulating position and angle for picking, transferring and releasing. The failure behaviors of pick-up are built to realize the efficient three-dimensional manipulation of microcopper wire of 300 μm. By establishing a theoretical model and experimental verification, it was concluded that the middle point was the best manipulating position when picking up the microcopper wire, the most efficient picking angle was between 45 and 60 degrees for the pipette, and the average time was 480 s in three sets of picking–release manipulation experiments. This paper provides an achievable idea for different types of micro-object manipulations and promotes the rapid application of micromanipulation techniques in MEMSs. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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8 pages, 1738 KiB

Open AccessArticle

Compact Magnetic Force Microscope (MFM) System in a 12 T Cryogen-Free Superconducting Magnet

by Asim Abas, Tao Geng, Wenjie Meng, Jihao Wang, Qiyuan Feng, Jing Zhang, Ze Wang, Yubin Hou and Qingyou Lu

Micromachines 2022, 13(11), 1922; https://doi.org/10.3390/mi13111922 - 7 Nov 2022

Cited by 2 | Viewed by 1860

Abstract

Magnetic Force Microscopy (MFM) is among the best techniques for examining and assessing local magnetic characteristics in surface structures at scales and sizes. It may be viewed as a unique way to operate atomic force microscopy with a ferromagnetic tip. The enhancement of [...] Read more.

Magnetic Force Microscopy (MFM) is among the best techniques for examining and assessing local magnetic characteristics in surface structures at scales and sizes. It may be viewed as a unique way to operate atomic force microscopy with a ferromagnetic tip. The enhancement of magnetic signal resolution, the utilization of external fields during measurement, and quantitative data analysis are now the main areas of MFM development. We describe a new structure of MFM design based on a cryogen-free superconducting magnet. The piezoelectric tube (PZT) was implemented with a tip-sample coarse approach called SpiderDrive. The technique uses a magnetic tip on the free end of a piezo-resistive cantilever which oscillates at its resonant frequency. We obtained a high-quality image structure of the magnetic domain of commercial videotape under extreme conditions at 5 K, and a high magnetic field up to 11 T. When such a magnetic field was gradually increased, the domain structure of the videotape did not change much, allowing us to maintain the images in the specific regions to exhibit the performance. In addition, it enabled us to locate the sample region in the order of several hundred nanometers. This system has an extensive range of applications in the exploration of anisotropic magnetic phenomena in topological materials and superconductors. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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17 pages, 5338 KiB

Open AccessArticle

Deep-Eutectic-Solvent-Assisted Synthesis of a Z-Scheme BiVO₄/BiOCl/S,N-GQDS Heterojunction with Enhanced Photocatalytic Degradation Activity under Visible-Light Irradiation

by Hengxin Ren, Kuilin Lv, Wenbin Liu, Pengfei Li, Yu Zhang and Yuguang Lv

Micromachines 2022, 13(10), 1604; https://doi.org/10.3390/mi13101604 - 27 Sep 2022

Cited by 3 | Viewed by 2271

Abstract

Z-scheme heterojunction photocatalytic nanomaterial designs have attracted attention due to their high catalytic performance. Deep eutectic solvents (DESs) have been used as green, sustainable media, acting as solvents and structure inducers in the synthesis of nanomaterials. In this work, a novel visible-light-absorption-enhanced bismuth [...] Read more.

Z-scheme heterojunction photocatalytic nanomaterial designs have attracted attention due to their high catalytic performance. Deep eutectic solvents (DESs) have been used as green, sustainable media, acting as solvents and structure inducers in the synthesis of nanomaterials. In this work, a novel visible-light-absorption-enhanced bismuth vanadate/bismuth oxychloride/sulfur, nitrogen co-doped graphene quantum dot (BiVO₄/BiOCl/S,N-GQDS) heterojunction photocatalyst was prepared in a deep eutectic solvent. The photosynthetic activity of the BiVO₄/BiOCl/S,N-GQDS composite was determined by the photocatalytic degradation of rhodamine B (RhB) under visible-light irradiation. The results showed that the highest photocatalytic activity of BiVO₄/BiOCl/S,N-GQDS was achieved when the doping amount of S,N-GQDS was 3%, and the degradation rate of RhB reached 70% within 5 h. The kinetic and photocatalytic cycles showed that the degradation of Rhb was in accordance with the quasi-primary degradation kinetic model, and the photocatalytic performance remained stable after four photocatalytic cycles. Ultraviolet–visible diffuse reflectance (UV-DRS) and photoluminescence (PL) experiments confirmed that BiVO₄/BiOCl/S,N-GQDS ternary heterojunctions have a narrow band gap energy (2.35 eV), which can effectively improve the separation efficiency of the photogenerated electron–hole pairs and suppress their complexation. This is due to the construction of a Z-scheme charge process between the BiVO₄/BiOCl binary heterojunction and S,N-GQDS, which achieves effective carrier separation and thus a strong photocatalytic capability. This work not only provides new insights into the design of catalysts using a green solvent approach but also provides a reference for the study of heterojunction photocatalytic materials based on bismuth vanadate, as well as new ideas for other photocatalytic materials. Full article

(This article belongs to the Special Issue Selected Papers from the 24th Annual Conference and 13th International Conference of Chinese Society of Micro-Nano Technology (CSMNT 2022))

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