Micromachines

13 pages, 7051 KiB

Open AccessArticle

A Five-Hole Pressure Probe Based on Integrated MEMS Fiber-Optic Fabry-Perot Sensors

by Yumiao Song, Shuanghui Ma, Jichun Zhao, Jia Liu, Jingyi Wang and Yongjun Cui

Micromachines 2024, 15(4), 554; https://doi.org/10.3390/mi15040554 - 22 Apr 2024

Viewed by 2841

The five-hole pressure probe based on Micro-Electro-Mechanical Systems (MEMS) technology is designed to meet the needs of engine inlet pressure measurement. The probe, including a pressure-sensitive detection unit and a five-hole probe encapsulation structure, combines the advantages of a five-hole probe with fiber [...] Read more.

The five-hole pressure probe based on Micro-Electro-Mechanical Systems (MEMS) technology is designed to meet the needs of engine inlet pressure measurement. The probe, including a pressure-sensitive detection unit and a five-hole probe encapsulation structure, combines the advantages of a five-hole probe with fiber optic sensing. The pressure-sensitive detection unit utilizes silicon-glass anodic bonding to achieve the integrated and batch-producible manufacturing of five pressure-sensitive Fabry–Perot (FP) cavities. The probe structure and parameters of the sensitive unit were optimized based on fluid and mechanical simulations. The non-scanning correlation demodulation technology was applied to extract specific cavity lengths from multiple interference surfaces. The sealing platform was established to analyze the sealing performance of the five-hole probe and the pressure-sensitive detection unit. The testing platform was established to test the pressure response characteristics of the probe. Experimental results indicate that the probe has good sealing performance between different air passages, making it suitable for detecting pressure from multiple directions. The pressure responses are linear within the range of 0–250 kPa, with the average pressure sensitivity of the five sensors ranging from 11.061 to 11.546 nm/kPa. The maximum non-linear error is ≤1.083%. Full article

(This article belongs to the Special Issue Micro/Nano Sensors: Fabrication and Applications)

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34 pages, 5929 KiB

Open AccessArticle

Robust Orientation Estimation from MEMS Magnetic, Angular Rate, and Gravity (MARG) Modules for Human–Computer Interaction

by Pontakorn Sonchan, Neeranut Ratchatanantakit, Nonnarit O-Larnnithipong, Malek Adjouadi and Armando Barreto

Micromachines 2024, 15(4), 553; https://doi.org/10.3390/mi15040553 - 21 Apr 2024

Cited by 2 | Viewed by 3665

Abstract

While the availability of low-cost micro electro-mechanical systems (MEMS) accelerometers, gyroscopes, and magnetometers initially seemed to promise the possibility of using them to easily track the position and orientation of virtually any object that they could be attached to, this promise has not [...] Read more.

While the availability of low-cost micro electro-mechanical systems (MEMS) accelerometers, gyroscopes, and magnetometers initially seemed to promise the possibility of using them to easily track the position and orientation of virtually any object that they could be attached to, this promise has not yet been fulfilled. Navigation-grade accelerometers and gyroscopes have long been the basis for tracking ships and aircraft, but the signals from low-cost MEMS accelerometers and gyroscopes are still orders of magnitude poorer in quality (e.g., bias stability). Therefore, the applications of MEMS inertial measurement units (IMUs), containing tri-axial accelerometers and gyroscopes, are currently not as extensive as they were expected to be. Even the addition of MEMS tri-axial magnetometers, to conform magnetic, angular rate, and gravity (MARG) sensor modules, has not fully overcome the challenges involved in using these modules for long-term orientation estimation, which would be of great benefit for the tracking of human–computer hand-held controllers or tracking of Internet-Of-Things (IoT) devices. Here, we present an algorithm, GMVDμK (or simply GMVDK), that aims at taking full advantage of all the signals available from a MARG module to robustly estimate its orientation, while preventing damaging overcorrections, within the context of a human–computer interaction application. Through experimental comparison, we show that GMVDK is more robust to magnetic disturbances than three other MARG orientation estimation algorithms in representative trials. Full article

(This article belongs to the Special Issue Exploring IoT Sensors and Their Applications: Advancements, Challenges, and Opportunities in Smart Environments)

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27 pages, 522 KiB

Open AccessArticle

Secure ECDSA SRAM-PUF Based on Universal Single/Double Scalar Multiplication Architecture

by Jingqi Zhang, Zhiming Chen, Xiang He, Kuanhao Liu, Yue Hao, Mingzhi Ma, Weijiang Wang, Hua Dang and Xiangnan Li

Micromachines 2024, 15(4), 552; https://doi.org/10.3390/mi15040552 - 21 Apr 2024

Viewed by 1276

Abstract

Physically unclonable functions (PUFs) are crucial for enhancing cybersecurity by providing unique, intrinsic identifiers for electronic devices, thus ensuring their authenticity and preventing unauthorized cloning. The SRAM-PUF, characterized by its simple structure and ease of implementation in various scenarios, has gained widespread usage. [...] Read more.

Physically unclonable functions (PUFs) are crucial for enhancing cybersecurity by providing unique, intrinsic identifiers for electronic devices, thus ensuring their authenticity and preventing unauthorized cloning. The SRAM-PUF, characterized by its simple structure and ease of implementation in various scenarios, has gained widespread usage. The soft-decision Reed–Muller (RM) code, an error correction code, is commonly employed in these designs. This paper introduces the design of an RM code soft-decision attack algorithm to reveal its potential security risks. To address this problem, we propose a soft-decision SRAM-PUF structure based on the elliptic curve digital signature algorithm (ECDSA). To improve the processing speed of the proposed secure SRAM-PUF, we propose a custom ECDSA scheme. Further, we also propose a universal architecture for the critical operations in ECDSA, elliptic curve scalar multiplication (ECSM), and elliptic curve double scalar multiplication (ECDSM) based on the differential addition chain (DAC). For ECSMs, iterations can be performed directly; for ECDSMs, a two-dimensional DAC is constructed through precomputation, followed by iterations. Moreover, due to the high similarity of ECSM and ECDSM data paths, this universal architecture saves hardware resources. Our design is implemented on a field-programmable gate array (FPGA) and an application-specific integrated circuit (ASIC) using a Xilinx Virtex-7 and an TSMC 40 nm process. Compared to existing research, our design exhibits a lower bit error rate (

2.7 \times 10^{- 10}

) and better area–time performance (3902 slices, 6.615

μ

s ECDSM latency). Full article

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14 pages, 4910 KiB

Open AccessArticle

Enhancing Thickness Uniformity of Nb₂O₅/SiO₂ Multilayers Using Shadow Masks for Flexible Color-Filtering Applications

by Tzu-Chien Li, Dong-Lin Li, Jiashow Ho, Chih-Chiang Yu, Sheng-Shih Wang and Jyh-Jier Ho

Micromachines 2024, 15(4), 551; https://doi.org/10.3390/mi15040551 - 21 Apr 2024

Cited by 1 | Viewed by 1335

Abstract

Using a stainless shadow mask combined with a magnetron-ion-assisted deposition (IAD) sputtering system, we investigate the surface morphologies and optical properties of microfilms. Optimal color-filter (CF) coating microfilms with niobium pent-oxide (Nb₂O₅)/silicon dioxide (SiO₂) multilayers on a [...] Read more.

Using a stainless shadow mask combined with a magnetron-ion-assisted deposition (IAD) sputtering system, we investigate the surface morphologies and optical properties of microfilms. Optimal color-filter (CF) coating microfilms with niobium pent-oxide (Nb₂O₅)/silicon dioxide (SiO₂) multilayers on a hard polycarbonate (HPC) substrate, grown at 85 °C and 50 SCCM oxygen flow, can obtain a fairly uniform thickness (with an average roughness of 0.083 and 0.106 nm respectively for Nb₂O₅ and SiO₂ films) through all positions. On a flexible HPC substrate with the Nb₂O₅/SiO₂ microfilms, meanwhile, the peak transmittances measured in the visible range are 95.70% and 91.47%, respectively, for coatings with and without a shadow mask for this new-tech system. For the optimal CF application with a shadow mask, transmittance on each 100 nm band-pass wavelength is enhanced by 4.04% absolute (blue), 2.96% absolute (green), and 2.12% absolute (red). Moreover, the developed new-tech system not only enhances the quality of the films by achieving smoother and uniform surfaces but also reduces deposition time, thereby improving overall process efficiency. For the with-shadow-mask condition, there is little shift at 50% transmittance (T50%), and high transmittance (~97%) is maintained after high-temperature (200 °C) baking for 12 h. These results are well above the commercial CF standard (larger than 90%) and demonstrate reliability and good durability for flexible optical applications. Full article

(This article belongs to the Special Issue Multi-dimensional (1D, 2D, 3D) Micro/Nanocomposite Thin Films and Crystals)

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16 pages, 6766 KiB

Open AccessArticle

Electromagnetic Acoustic Detection of Pipe Defects Hidden above T-Type Support Structures with Circumferential Shear Horizontal Guided Wave

by Xingjun Zhang, Jinjie Zhou, Yang Hu, Yao Liu and Xingquan Shen

Micromachines 2024, 15(4), 550; https://doi.org/10.3390/mi15040550 - 20 Apr 2024

Cited by 2 | Viewed by 1138

Abstract

When pipe defects are generated above the T-type support structure location, it is difficult to distinguish the reflection signals caused by the weld bead at the support structure from the reflection echoes of pipe defects. Therefore, in order to effectively detect pipe defects, [...] Read more.

When pipe defects are generated above the T-type support structure location, it is difficult to distinguish the reflection signals caused by the weld bead at the support structure from the reflection echoes of pipe defects. Therefore, in order to effectively detect pipe defects, a waveform subtraction method with a circumferential shear horizontal (CSH) guided wave is proposed, which is generated by an electromagnetic acoustic transducer (EMAT). First, a CSH₀ guided wave mode with a center frequency of 500 kHz is selected to establish a three-dimensional model with and without pipe defects above the support structure. Following this, the influence of different widths of support structures on the echo signal is compared. Moreover, simulation and experimental results are used to compare the influence of different welding qualities on the detection results. Finally, the waveform subtraction method is used to process the simulation and experimental signals, and the influence of pipe defects with different lengths and depths is discussed. The results show that the non-through crack defect of 5 mm × 1 mm (length × depth) can be detected. The results show that this method can effectively detect the cracks by eliminating the influence of the weld echo, which provides a new concept for the detection of the defect above the support structure. Full article

(This article belongs to the Special Issue Acoustic Transducers and Their Applications)

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15 pages, 1542 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Optimization of Graphical Parameter Extraction Algorithm for Chip-Level CMP Prediction Model Based on Effective Planarization Length

by Bowen Ren, Lan Chen, Rong Chen, Yan Sun and Yali Wang

Micromachines 2024, 15(4), 549; https://doi.org/10.3390/mi15040549 - 19 Apr 2024

Viewed by 1062

Abstract

As a planarization technique, chemical mechanical polishing (CMP) continues to suffer from pattern effects that result in large variations in material thickness, which can influence circuit performance and yield. Therefore, tools for predicting post-CMP chip morphology based on the layout-dependent effect (LDE) have [...] Read more.

As a planarization technique, chemical mechanical polishing (CMP) continues to suffer from pattern effects that result in large variations in material thickness, which can influence circuit performance and yield. Therefore, tools for predicting post-CMP chip morphology based on the layout-dependent effect (LDE) have become increasingly critical and widely utilized for design verification and manufacturing development. In order to characterize the impact of patterns on polishing, such models often require the extraction of graphic parameters. However, existing extraction algorithms provide a limited description of the interaction effect between layout patterns. To address this problem, we calculate the average density as a density correction and innovatively use a one-dimensional line contact deformation profile as a weighting function. To verify our hypothesis, the density correction method is applied to a density step-height-based high-K metal gate-CMP prediction model. The surface prediction results before and after optimization are compared with the silicon data. The results show a reduction in mean squared error (MSE) of 40.1% and 35.2% in oxide and Al height predictions, respectively, compared with the preoptimization results, confirming that the optimization method can improve the prediction accuracy of the model. Full article

(This article belongs to the Special Issue Advances in Micro and Nano Manufacturing: Process Modeling and Applications, 3rd Edition)

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13 pages, 4023 KiB

Open AccessArticle

Research on Vibration Accumulation Self-Powered Downhole Sensor Based on Triboelectric Nanogenerators

by Rui Wang, Jianchao Ren, Weibo Ding, Maofu Liu, Guangzhi Pan and Chuan Wu

Micromachines 2024, 15(4), 548; https://doi.org/10.3390/mi15040548 - 19 Apr 2024

Cited by 2 | Viewed by 985

Abstract

In drilling operations, measuring vibration parameters is crucial for enhancing drilling efficiency and ensuring safety. Nevertheless, the conventional vibration measurement sensor significantly extends the drilling cycle due to its dependence on an external power source. Therefore, we propose a vibration-accumulation-type self-powered sensor in [...] Read more.

In drilling operations, measuring vibration parameters is crucial for enhancing drilling efficiency and ensuring safety. Nevertheless, the conventional vibration measurement sensor significantly extends the drilling cycle due to its dependence on an external power source. Therefore, we propose a vibration-accumulation-type self-powered sensor in this research, aiming to address these needs. By leveraging vibration accumulation and electromagnetic power generation to accelerate charging, the sensor’s output performance is enhanced through a complementary charging mode. The experimental results regarding sensing performance demonstrate that the sensor possesses a measurement range spanning from 0 to 11 Hz, with a linearity of 3.2% and a sensitivity of 1.032. Additionally, it exhibits a maximum average measurement error of less than 4%. The experimental results of output performance measurement indicate that the sensor unit and generator set exhibit a maximum output power of 0.258 μW and 25.5 mW, respectively, and eight LED lights can be lit at the same time. When the sensor unit and power generation unit output together, the maximum output power of the sensor is also 25.5 mW. Furthermore, we conducted tests on the sensor’s output signal in conditions of high temperature and humidity, confirming its continued functionality in such environments. This sensor not only achieves self-powered sensing capabilities, addressing the power supply challenges faced by traditional downhole sensors, but also integrates energy accumulation with electromagnetic power generation to enhance its output performance. This innovation enables the sensor to harness downhole vibration energy for powering other micro-power devices, showcasing promising application prospects. Full article

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18 pages, 10749 KiB

Open AccessReview

Research and Application Progress of Laser-Processing Technology in Diamond Micro-Fabrication

by Yangfan Zhang, Shuai Xu, E-Nuo Cui, Ling Yu and Zhan Wang

Micromachines 2024, 15(4), 547; https://doi.org/10.3390/mi15040547 - 18 Apr 2024

Cited by 4 | Viewed by 3973

Abstract

Laser-processing technology has been widely used in the ultra-precision machining of diamond materials. It has the advantages of high precision and high efficiency, especially in the field of super-hard materials and high-precision parts manufacturing. This paper explains the fundamental principles of diamond laser [...] Read more.

Laser-processing technology has been widely used in the ultra-precision machining of diamond materials. It has the advantages of high precision and high efficiency, especially in the field of super-hard materials and high-precision parts manufacturing. This paper explains the fundamental principles of diamond laser processing, introduces the interaction mechanisms between various types of lasers and diamond materials, focuses on analyzing the current development status of various modes of laser processing of diamond, briefly discusses the relevant applications in diamond cutting, micro-hole forming, and micro-groove machining, etc., and finally discusses the issues, challenges, and potential future advancements of laser technology in the field of diamond processing at this point. Full article

(This article belongs to the Special Issue Advanced Manufacturing Technology and Systems, 3rd Edition)

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12 pages, 5870 KiB

Open AccessArticle

Ultra-Wideband Transformer Feedback Monolithic Microwave Integrated Circuit Power Amplifier Design on 0.25 μm GaN Process

by Jialin Luo, Yihui Fan, Jing Wan, Xuming Sun and Xiaoxin Liang

Micromachines 2024, 15(4), 546; https://doi.org/10.3390/mi15040546 - 18 Apr 2024

Viewed by 1170

Abstract

This paper presents an ultra-wideband transformer feedback (TFB) monolithic microwave integrated circuit (MMIC) power amplifier (PA) developed using a 0.25 μm gallium nitride (GaN) process. To broaden the bandwidth, a drain-to-gate TFB technique is employed in this PA design, achieving a 117% relative [...] Read more.

This paper presents an ultra-wideband transformer feedback (TFB) monolithic microwave integrated circuit (MMIC) power amplifier (PA) developed using a 0.25 μm gallium nitride (GaN) process. To broaden the bandwidth, a drain-to-gate TFB technique is employed in this PA design, achieving a 117% relative −3 dB bandwidth, extending from 5.4 GHz to 20.3 GHz. At a 28 V supply, the designed PA circuit achieves an output power of 25.5 dBm and a 14 dB small-signal gain in the frequency range of 6 to 19 GHz. Within the 6 to 19 GHz frequency range, the small-signal gain exhibits a flatness of less than 0.78 dB. The PA chip occupies an area of 1.571 mm². This work is the first to design a power amplifier with on-chip transformer feedback in a compound semiconductor MMIC process, and it enables the use of the widest bandwidth power amplifier on-chip transformer matching network. Full article

(This article belongs to the Special Issue Advances in GaN- and SiC-Based Electronics: Design and Applications)

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21 pages, 4058 KiB

Open AccessArticle

Resistance Feedback of a Ni-Ti Alloy Actuator at Room Temperature in Still Air

by Francesco Durante, Terenziano Raparelli and Pierluigi Beomonte Zobel

Micromachines 2024, 15(4), 545; https://doi.org/10.3390/mi15040545 - 18 Apr 2024

Cited by 2 | Viewed by 993

Abstract

This paper illustrates an experimental activity for the closed-loop position control of an actuator made using shape memory alloy (SMA) wire. A solution with the self-sensing effect was implemented to miniaturize the systems, i.e., without external sensors. A proportional control algorithm was initially [...] Read more.

This paper illustrates an experimental activity for the closed-loop position control of an actuator made using shape memory alloy (SMA) wire. A solution with the self-sensing effect was implemented to miniaturize the systems, i.e., without external sensors. A proportional control algorithm was initially used, demonstrating the idea’s feasibility; the wire can behave simultaneously as an actuator and sensor. An experimental investigation was subsequently conducted for the optimization of the developed actuator. As for the material, a Flexinol wire, Ni-Ti alloy, with a diameter of 0.150 mm and a length of 200 mm, was used. Preliminarily, characterization of the SMA wire at constant and variable loads was carried out; the characteristics detected were elongation vs. electric current and elongation vs. electrical resistance. The control system is PC based with a data acquisition card (DAQ). A drive board was designed and built to read the wire’s electrical resistance and power it by pulse width modulation (PWM). A notable result is that the actuator works with good precision and in dynamic conditions, even when it is called to support a load up to 65% different from that for which the electrical resistance–length correlation has previously been experimentally obtained, on which the control is based. This opens up the possibility of using the actuator in a counteracting configuration with a spring, which makes hardware implementation and control management simple. Full article

(This article belongs to the Special Issue Smart Material-Based Micromechatronics in Soft Robotics)

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16 pages, 7169 KiB

Open AccessArticle

Design and Characterization of Surface Acoustic Wave-Based Wireless and Passive Temperature Sensing System

by Zhixin Zhou, Hui Wang and Liang Lou

Micromachines 2024, 15(4), 544; https://doi.org/10.3390/mi15040544 - 18 Apr 2024

Viewed by 3339

Abstract

The surface acoustic wave (SAW) temperature sensor has received significant attention due to its wirelessly powered, battery-free, and chipless capabilities. This paper proposes a wireless sensing system comprising a one-port SAW resonator, helix antenna, and transceiver circuit. The SAW resonator used in this [...] Read more.

The surface acoustic wave (SAW) temperature sensor has received significant attention due to its wirelessly powered, battery-free, and chipless capabilities. This paper proposes a wireless sensing system comprising a one-port SAW resonator, helix antenna, and transceiver circuit. The SAW resonator used in this system is based on aluminum nitride (AlN) thin film, which exhibits high velocity and excellent piezoelectric properties. Simulations and experiments were conducted to investigate the performance of the designed SAW resonator. A helix antenna was also designed using finite element simulation to facilitate signal transmission between the SAW temperature sensor and the transceiver. An impedance-matching network was introduced between the helix antenna and the SAW resonator to optimize signal transmission. When the wireless SAW temperature sensor was placed within a certain distance of the mother antenna, the reflection peak of the SAW resonator was observed in the spectrum of the return signal. The frequency of the echo signal increased almost linearly as the temperature increased during the temperature tests. The fitted temperature coefficient of frequency (TCF) was −31.34 ppm/°C, indicating that the wireless temperature sensing system has high-temperature sensitivity. Full article

(This article belongs to the Special Issue Acoustic Transducers and Their Applications)

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13 pages, 6979 KiB

Open AccessArticle

Analysis of Experimental Biaxial Surface Wrinkling Pattern Based on Direct 3D Numerical Simulation

by Seonho Seok, HyungDal Park and Jinseok Kim

Micromachines 2024, 15(4), 543; https://doi.org/10.3390/mi15040543 - 18 Apr 2024

Viewed by 957

Abstract

This paper presents a direct 3D numerical simulation of biaxial surface wrinkling of thin metal film on a compliant substrate. The selected compliant substrate is a commercial Scotch tape on which a gold metal thin film has been transferred by using low adhesion [...] Read more.

This paper presents a direct 3D numerical simulation of biaxial surface wrinkling of thin metal film on a compliant substrate. The selected compliant substrate is a commercial Scotch tape on which a gold metal thin film has been transferred by using low adhesion between the thin metal film and polyimide substrate. Compared with the previous fabrication of a cylindrical thin-film wrinkling pattern, an undulated wrinkling pattern has been implemented by increasing the width of the thin metal film in order to create biaxial straining in the thin film. To understand the wrinkling behavior due to biaxial loading, a simple direct numerical simulation based on material imperfections defined in the compliant substrate has been conducted. Through modeling and simulation, it was found that the wrinkling mode is determined by the biaxiality ratio (BR), the ratio between transversal strain and longitudinal strain. Depending on the BR, the wrinkling mode belongs to one of the cylindrical, undulated (or herringbone), checkerboard, or labyrinth modes as a function of applied strain. The cylindrical wrinkling is dominant at the input of BR less than 0.5, while the undulated (or herringbone) ones become dominant just after the onset of the wrinkling pattern at BR greater than 0.9. Through the comparison of the wrinkling patterns between simulation and experiment, the applied BR of the fabricated thin film has been successfully estimated. Full article

(This article belongs to the Special Issue Advances in Micro and Nano Manufacturing: Process Modeling and Applications, 3rd Edition)

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14 pages, 2743 KiB

Open AccessArticle

Precision Phenotypic Profiling and Capture of Circulating Tumor Cells via a Vertical Laminar Flow-Stacked Microfluidic Chip

by Xinping Zhang, Yuan Ma, Yujiao Wang, Zhenwei Liang, Xuanhe Zhang, Yiqing Chen, Qingyi Wang, Hua Qin and Jiadao Wang

Micromachines 2024, 15(4), 542; https://doi.org/10.3390/mi15040542 - 18 Apr 2024

Viewed by 3267

Abstract

The heterogeneity of circulating tumor cells has a significant impact on the diagnosis, treatment, and monitoring of cancer. Research on the subtypes of circulating tumor cells can bring better treatment outcomes for cancer patients. Here, we proposed a microfluidic chip for the magnetic [...] Read more.

The heterogeneity of circulating tumor cells has a significant impact on the diagnosis, treatment, and monitoring of cancer. Research on the subtypes of circulating tumor cells can bring better treatment outcomes for cancer patients. Here, we proposed a microfluidic chip for the magnetic capture of subtypes of circulating tumor cells from the whole blood and phenotypic profiling by stacking laminar flow vertically. Circulating tumor cells were sorted and captured by the three-dimensional regulation of both magnetic fields in the vertical direction and flow fields in the lateral direction. Using EpCAM-magnetic beads, we achieved sorting and sectional capture of target cells in whole blood and analyzed the surface expression levels of the captured cells, confirming the functionality of the microfluidic chip in sorting and capturing subtypes of circulating tumor cells. This microfluidic chip can also aid in the subsequent subtype analysis of other rare cells. Full article

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14 pages, 5343 KiB

Open AccessArticle

A Method for Automatically Predicting the Radiation-Induced Vulnerability of Unit Integrated Circuits

by Rui Dong, Hongliang Lu, Caozhen Yang, Yutao Zhang, Ruxue Yao, Yujian Wang and Yuming Zhang

Micromachines 2024, 15(4), 541; https://doi.org/10.3390/mi15040541 - 18 Apr 2024

Cited by 1 | Viewed by 1011

Abstract

With the rapid development of semiconductor technology, the reduction in device operating voltage and threshold voltage has made integrated circuits more susceptible to the effects of particle radiation. Moreover, as process sizes decrease, the impact of charge sharing effects becomes increasingly severe, with [...] Read more.

With the rapid development of semiconductor technology, the reduction in device operating voltage and threshold voltage has made integrated circuits more susceptible to the effects of particle radiation. Moreover, as process sizes decrease, the impact of charge sharing effects becomes increasingly severe, with soft errors caused by single event effects becoming one of the main causes of circuit failures. Therefore, the study of sensitivity evaluation methods for integrated circuits is of great significance for promoting the optimization of integrated circuit design, improving single event effect experimental methods, and enhancing the irradiation reliability of integrated circuits. In this paper, we first established a device model for the charge sharing effect and simulated it under reasonable conditions. Based on the simulation results, we then built a neural network model to predict the charge amounts in primary and secondary devices. We also propose a comprehensive automated method for calculating soft errors in unit circuits and validated it through TCAD simulations, achieving an error margin of 2.8–4.3%. This demonstrated the accuracy and effectiveness of the method we propose. Full article

(This article belongs to the Special Issue High-Reliability Semiconductor Devices and Integrated Circuits, 2nd Edition)

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12 pages, 4270 KiB

Open AccessArticle

The Effect of Height Error on Performance of Propagation Phase-Based Metalens

by Yongxue Qiu, Liangui Deng, Yujie Zhan, Gongfa Li and Jianguo Guan

Micromachines 2024, 15(4), 540; https://doi.org/10.3390/mi15040540 - 17 Apr 2024

Viewed by 1039

Abstract

Metalenses, as a new type of planar optical device with flexible design, play an important role in miniaturized and integrated optical devices. Propagation phase-based metalenses, known for their low loss and extensive design flexibility, are widely utilized in optical imaging and optical communication. [...] Read more.

Metalenses, as a new type of planar optical device with flexible design, play an important role in miniaturized and integrated optical devices. Propagation phase-based metalenses, known for their low loss and extensive design flexibility, are widely utilized in optical imaging and optical communication. However, fabrication errors introduced by thin-film deposition and etching processes inevitably result in variations in the height of the metalens structure, leading to the fabricated devices not performing as expected. Here, we introduce a reflective TiO₂ metalens based on the propagation phase. Then, the relationship between the height variation and the performance of the metalens is explored by using the maximum phase error. Our results reveal that the height error of the unit structure affects the phase rather than the amplitude. The focusing efficiency of our metalens exhibits robustness to structural variations, with only a 5% decrease in focusing efficiency when the height varies within ±8% of the range. The contents discussed in this paper provide theoretical guidance for the unit design of the propagation phase-based metalens and the determination of its allowable fabrication error range, which is of great significance for low-cost and high-efficiency manufacturing. Full article

(This article belongs to the Special Issue Optical Micro–Nano Structures and Devices: Materials, Design and Applications)

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12 pages, 4841 KiB

Open AccessArticle

Design and Simulation of a 19-Electrode MEMS Piezoelectric Thin-Film Micro-Deformable Mirror for Ophthalmology

by Yisen Hu, Hongbo Yin, Maoying Li, Tianyu Bai, Liang He, Zhimin Hu, Yuanlin Xia and Zhuqing Wang

Micromachines 2024, 15(4), 539; https://doi.org/10.3390/mi15040539 - 17 Apr 2024

Cited by 1 | Viewed by 3094

Abstract

This study presents a numerical simulation-based investigation of a MEMS (micro-electromechanical systems)technology-based deformable mirror employing a piezoelectric film for fundus examination in adaptive optics. Compared to the classical equal-area electrode arrangement model, we optimize the electrode array for higher-order aberrations. The optimized model [...] Read more.

This study presents a numerical simulation-based investigation of a MEMS (micro-electromechanical systems)technology-based deformable mirror employing a piezoelectric film for fundus examination in adaptive optics. Compared to the classical equal-area electrode arrangement model, we optimize the electrode array for higher-order aberrations. The optimized model centralizes electrodes around the mirror center, which realizes low-voltage driving with high-accuracy correction. The optimized models exhibited commendable correction abilities, achieving a unidirectional displacement of 5.74 μm with a driven voltage of 15 V. The voltage–displacement relationship demonstrated high linearity at 0.99. Furthermore, the deformable mirror’s influence matrix was computed, aligning with the Zernike standard surface shape of the order 1–3. To quantify aberration correction capabilities, fitting residuals for both models were calculated. The results indicate an average removal of 96.8% of aberrations to the human eye. This underscores that the optimized model outperforms the classical model in correcting high-order aberrations. Full article

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12 pages, 1955 KiB

Open AccessArticle

Design of Far-Infrared High-Efficiency Polarization-Independent Retroreflective Metasurfaces

by Siliang Zhou, Siyu Dong, Tao He, Jingyuan Zhu, Zhanshan Wang and Xinbin Cheng

Micromachines 2024, 15(4), 538; https://doi.org/10.3390/mi15040538 - 17 Apr 2024

Cited by 1 | Viewed by 1198

Abstract

Retroreflective gratings serve as fundamental optical elements in nanophotonics, with polarization-independent diffraction efficiency being one of the critical parameters for assessing their performance. In the far-infrared spectral range, traditional retroreflective gratings typically refer to metal echelette gratings, but their diffraction efficiency cannot approach [...] Read more.

Retroreflective gratings serve as fundamental optical elements in nanophotonics, with polarization-independent diffraction efficiency being one of the critical parameters for assessing their performance. In the far-infrared spectral range, traditional retroreflective gratings typically refer to metal echelette gratings, but their diffraction efficiency cannot approach 100% due to metal absorption. In the visible and near-infrared spectral ranges, metal echelette gratings have gradually been replaced by all-dielectric metasurfaces because dielectric materials exhibit negligible absorption at specific wavelengths. However, there is still a lack of relevant research in the far-infrared range, mainly due to the weak control capability of the existing devices over the polarization-independent phase. Here, we propose a kind of all-dielectric retroreflective metasurface composed of asymmetric pillars and freely tunable aperiodic multilayer films. The pillar structure can achieve polarization insensitivity, and the insufficient modulation capability of the dielectric materials can be compensated for by aperiodic Ge/ZnS films. The designed metasurface achieves the diffraction efficiency by RCWA, with the maximum larger than 99% and the overall reaching 95% (9.3–9.6 µm). We have provided detailed explanations of the design methodology and fabrication process. Our work lays the groundwork for further exploration and application of far-infrared lasers. Full article

(This article belongs to the Special Issue Metamaterials for Sensing Applications)

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16 pages, 8977 KiB

Open AccessArticle

Extending the Depth of Focus of an Infrared Microscope Using a Binary Axicon Fabricated on Barium Fluoride

by Molong Han, Daniel Smith, Tauno Kahro, Dominyka Stonytė, Aarne Kasikov, Darius Gailevičius, Vipin Tiwari, Agnes Pristy Ignatius Xavier, Shivasubramanian Gopinath, Soon Hock Ng, Aravind Simon John Francis Rajeswary, Aile Tamm, Kaupo Kukli, Keith Bambery, Jitraporn Vongsvivut, Saulius Juodkazis and Vijayakumar Anand

Micromachines 2024, 15(4), 537; https://doi.org/10.3390/mi15040537 - 17 Apr 2024

Cited by 1 | Viewed by 1325

Abstract

Axial resolution is one of the most important characteristics of a microscope. In all microscopes, a high axial resolution is desired in order to discriminate information efficiently along the longitudinal direction. However, when studying thick samples that do not contain laterally overlapping information, [...] Read more.

Axial resolution is one of the most important characteristics of a microscope. In all microscopes, a high axial resolution is desired in order to discriminate information efficiently along the longitudinal direction. However, when studying thick samples that do not contain laterally overlapping information, a low axial resolution is desirable, as information from multiple planes can be recorded simultaneously from a single camera shot instead of plane-by-plane mechanical refocusing. In this study, we increased the focal depth of an infrared microscope non-invasively by introducing a binary axicon fabricated on a barium fluoride substrate close to the sample. Preliminary results of imaging the thick and sparse silk fibers showed an improved focal depth with a slight decrease in lateral resolution and an increase in background noise. Full article

(This article belongs to the Special Issue Photonic and Optoelectronic Devices and Systems, Second Edition)

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11 pages, 4082 KiB

Open AccessCommunication

The Effect of the Barrier Layer on the Uniformity of the Transport Characteristics of AlGaN/GaN Heterostructures on HR-Si(111)

by Yujie Yan, Yangbowen Liu, Guodong Xiong, Jun Huang and Bing Yang

Micromachines 2024, 15(4), 536; https://doi.org/10.3390/mi15040536 - 16 Apr 2024

Viewed by 1065

Abstract

The high transport characteristics of AlGaN/GaN heterostructures are critical components for high-performance electronic and radio-frequency (RF) devices. We report the transport characteristics of AlGaN/GaN heterostructures grown on a high-resistivity (HR) Si(111) substrate, which are unevenly distributed in the central and edge regions of [...] Read more.

The high transport characteristics of AlGaN/GaN heterostructures are critical components for high-performance electronic and radio-frequency (RF) devices. We report the transport characteristics of AlGaN/GaN heterostructures grown on a high-resistivity (HR) Si(111) substrate, which are unevenly distributed in the central and edge regions of the wafer. The relationship between the composition, stress, and polarization effects was discussed, and the main factors affecting the concentration and mobility of two-dimensional electron gas (2DEG) were clarified. We further demonstrated that the mechanism of changes in polarization intensity and scattering originates from the uneven distribution of Al composition and stress in the AlGaN barrier layer during the growth process. Furthermore, our results provide an important guide on the significance of accomplishing 6 inch AlGaN/GaN HEMT with excellent properties for RF applications. Full article

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13 pages, 4972 KiB

Open AccessArticle

A Compact Millimeter-Wave Multilayer Patch Antenna Array Based on a Mixed CPW-Slot-Couple Feeding Network

by Kun Deng, Naibo Zhang, Guangyao Yang, Yitong Li, Ruiliang Song and Ning Liu

Micromachines 2024, 15(4), 535; https://doi.org/10.3390/mi15040535 - 16 Apr 2024

Viewed by 1130

Abstract

A compact Ka-band antenna array has been proposed to realize broadband and high gain for millimeter-wave applications. The antenna array is divided into a multilayer composed of a driven slot patch layer and a parasitic patch array layer, which is excited by a [...] Read more.

A compact Ka-band antenna array has been proposed to realize broadband and high gain for millimeter-wave applications. The antenna array is divided into a multilayer composed of a driven slot patch layer and a parasitic patch array layer, which is excited by a mixed CPW-Slot-Couple feeding network layer. According to characteristic mode analysis, a pair of narrow coupling slots are introduced in the driven patch to move the resonant frequency of characteristic mode 3 to the resonant frequency of characteristic mode 2 for enhanced bandwidth. In this article, a 1to4 CPW-Slot-Couple feeding network for a 2 × 2 driven slot patch array is implemented, and then each driven slot patch excites a 2 × 2 parasitic patch array. Finally, a proposed 4 × 4 × 3 (row × column × layer) Ka-band antenna array is fabricated to verify the design concepts. The measured results show that the frequency bandwidth of the antenna array is 25 GHz to 32 GHz, and the relative bandwidth is 24.5%. The peak gain is 20.1 dBi. Due to its attractive properties of miniaturization, broadband, and high gain, the proposed antenna array could be applied to millimeter-wave wireless communication systems. Full article

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17 pages, 3139 KiB

Open AccessArticle

Light-Responsive Soft Robot Integrating Actuation and Function Based on Laser Cutting

by Ben Jia, Changbo Liu, Yi Zhang, Yujin Tan, Xuecheng Tian, Yuanyuan Cui and Yuan Deng

Micromachines 2024, 15(4), 534; https://doi.org/10.3390/mi15040534 - 16 Apr 2024

Viewed by 3638

Abstract

Soft robots with good deformability and adaptability have important prospects in the bionics and intelligence field. However, current research into soft robots is primarily limited to the study of actuators and ignores the integrated use of functional devices and actuators. To enrich the [...] Read more.

Soft robots with good deformability and adaptability have important prospects in the bionics and intelligence field. However, current research into soft robots is primarily limited to the study of actuators and ignores the integrated use of functional devices and actuators. To enrich the functions of soft robots and expand their application fields, it is necessary to integrate various functional electronic devices into soft robots to perform diverse functions during dynamic deformation. Therefore, this paper discusses methods and strategies to manufacture optical stimuli-responsive soft actuators and integrate them into functional devices for soft robots. Specifically, laser cutting allows us to fabricate an optically responsive actuator structure, e.g., the curling direction can be controlled by adjusting the direction of the cutting line. Actuators with different bending curvatures, including nonbending, can be obtained by adjusting the cutting depth, cutting width, and the spacing of the cutting line, which makes it easy to obtain a folded structure. Thus, various actuators with complex shape patterns can be obtained. In addition, we demonstrate a fabrication scheme for a worm-like soft robot integrated with functional devices (LEDs are used in this paper). The local nonbending design provides an asymmetric structure that provides driving power and avoids damage to the functional circuit caused by the large deformation during movement. The integration of drive and function provides a new path for the application of soft robots in the intelligence and bionics field. Full article

(This article belongs to the Special Issue Structural Analyses and Designs for Flexible/Stretchable Electronics, Volume II)

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21 pages, 2154 KiB

Open AccessFeature PaperEditor’s ChoiceReview

Biomaterials for Protein Delivery: Opportunities and Challenges to Clinical Translation

by Amogh Gorantla, Jacques T. V. E. Hall, Anneliese Troidle and Jelena M. Janjic

Micromachines 2024, 15(4), 533; https://doi.org/10.3390/mi15040533 - 15 Apr 2024

Viewed by 1970

Abstract

The development of biomaterials for protein delivery is an emerging field that spans materials science, bioengineering, and medicine. In this review, we highlight the immense potential of protein-delivering biomaterials as therapeutic options and discuss the multifaceted challenges inherent to the field. We address [...] Read more.

The development of biomaterials for protein delivery is an emerging field that spans materials science, bioengineering, and medicine. In this review, we highlight the immense potential of protein-delivering biomaterials as therapeutic options and discuss the multifaceted challenges inherent to the field. We address current advancements and approaches in protein delivery that leverage stimuli-responsive materials, harness advanced fabrication techniques like 3D printing, and integrate nanotechnologies for greater targeting and improved stability, efficacy, and tolerability profiles. We also discuss the demand for highly complex delivery systems to maintain structural integrity and functionality of the protein payload. Finally, we discuss barriers to clinical translation, such as biocompatibility, immunogenicity, achieving reliable controlled release, efficient and targeted delivery, stability issues, scalability of production, and navigating the regulatory landscape for such materials. Overall, this review summarizes insights from a survey of the current literature and sheds light on the interplay between innovation and the practical implementation of biomaterials for protein delivery. Full article

(This article belongs to the Special Issue Biomaterials, Biodevices and Tissue Engineering, Second Edition)

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13 pages, 3032 KiB

Open AccessArticle

Preparation and Investigation of a Nanosized Piroxicam Containing Orodispersible Lyophilizate

by Petra Party, Sándor Soma Sümegi and Rita Ambrus

Micromachines 2024, 15(4), 532; https://doi.org/10.3390/mi15040532 - 15 Apr 2024

Viewed by 1353

Abstract

Non-steroidal anti-inflammatory piroxicam (PRX) is a poorly water-soluble drug that provides relief in different arthritides. Reducing the particle size of PRX increases its bioavailability. For pediatric, geriatric, and dysphagic patients, oral dispersible systems ease administration. Moreover, fast disintegration followed by drug release and [...] Read more.

Non-steroidal anti-inflammatory piroxicam (PRX) is a poorly water-soluble drug that provides relief in different arthritides. Reducing the particle size of PRX increases its bioavailability. For pediatric, geriatric, and dysphagic patients, oral dispersible systems ease administration. Moreover, fast disintegration followed by drug release and absorption through the oral mucosa can induce rapid systemic effects. We aimed to produce an orodispersible lyophilizate (OL) consisting of nanosized PRX. PRX was solved in ethyl acetate and then sonicated into a poloxamer-188 solution to perform spray-ultrasound-assisted solvent diffusion-based nanoprecipitation. The solid form was formulated via freeze drying in blister sockets. Mannitol and sodium alginate were applied as excipients. Dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA) were used to determine the particle size. The morphology was characterized by scanning electron microscopy (SEM). To establish the crystallinity, X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC) were used. A disintegration and in vitro dissolution test were performed. DLS and NTA presented a nanosized PRX diameter. The SEM pictures showed a porous structure. PRX became amorphous according to the XRPD and DSC curves. The disintegration time was less than 1 min and the dissolution profile improved. The final product was an innovative anti-inflammatory drug delivery system. Full article

(This article belongs to the Special Issue Advanced Nanomaterials and Applied Nanotechnologies: Devices, Processes and Systems, 2nd Edition)

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31 pages, 451 KiB

Open AccessReview

Robotics Perception and Control: Key Technologies and Applications

by Jing Luo, Xiangyu Zhou, Chao Zeng, Yiming Jiang, Wen Qi, Kui Xiang, Muye Pang and Biwei Tang

Micromachines 2024, 15(4), 531; https://doi.org/10.3390/mi15040531 - 15 Apr 2024

Cited by 3 | Viewed by 5548

Abstract

The integration of advanced sensor technologies has significantly propelled the dynamic development of robotics, thus inaugurating a new era in automation and artificial intelligence. Given the rapid advancements in robotics technology, its core area—robot control technology—has attracted increasing attention. Notably, sensors and sensor [...] Read more.

The integration of advanced sensor technologies has significantly propelled the dynamic development of robotics, thus inaugurating a new era in automation and artificial intelligence. Given the rapid advancements in robotics technology, its core area—robot control technology—has attracted increasing attention. Notably, sensors and sensor fusion technologies, which are considered essential for enhancing robot control technologies, have been widely and successfully applied in the field of robotics. Therefore, the integration of sensors and sensor fusion techniques with robot control technologies, which enables adaptation to various tasks in new situations, is emerging as a promising approach. This review seeks to delineate how sensors and sensor fusion technologies are combined with robot control technologies. It presents nine types of sensors used in robot control, discusses representative control methods, and summarizes their applications across various domains. Finally, this survey discusses existing challenges and potential future directions. Full article

(This article belongs to the Special Issue Intelligent Human-Assisted Robotic Systems: From Microrobots to Wearable Robots)

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11 pages, 3662 KiB

Open AccessArticle

A 2 μm Wavelength Band Low-Loss Spot Size Converter Based on Trident Structure on the SOI Platform

by Zhutian Wang, Chenxi Xu, Zhiming Shi, Nan Ye, Hairun Guo, Fufei Pang and Yingxiong Song

Micromachines 2024, 15(4), 530; https://doi.org/10.3390/mi15040530 - 15 Apr 2024

Viewed by 1172

Abstract

A 2 μm wavelength band spot size converter (SSC) based on a trident structure is proposed, which is coupled to a lensed fiber with a mode field diameter of 5 μm. The cross-section of the first segment of the tapered waveguide structure in [...] Read more.

A 2 μm wavelength band spot size converter (SSC) based on a trident structure is proposed, which is coupled to a lensed fiber with a mode field diameter of 5 μm. The cross-section of the first segment of the tapered waveguide structure in the trident structure is designed as a right-angled trapezoidal shape, which can further improve the performance of the SSC. The coupling loss of the SSC is less than 0.9 dB in the wavelength range of 1.95~2.05 μm simulated by FDTD. According to the experimental results, the lowest coupling loss of the SSC is 1.425 dB/facet at 2 μm, which is close to the simulation result. The device is compatible with the CMOS process and can provide a good reference for the development of 2 μm wavelength band integrated photonics. Full article

(This article belongs to the Special Issue Silicon Photonic Devices and Integration)

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35 pages, 3013 KiB

Open AccessReview

Recent Advances in Carbon Nanotube Utilization in Perovskite Solar Cells: A Review

by Usman Asghar, Muhammad Azam Qamar, Othman Hakami, Syed Kashif Ali, Mohd Imran, Ahmad Farhan, Humaira Parveen and Mukul Sharma

Micromachines 2024, 15(4), 529; https://doi.org/10.3390/mi15040529 - 15 Apr 2024

Cited by 3 | Viewed by 2579

Abstract

Due to their exceptional optoelectronic properties, halide perovskites have emerged as prominent materials for the light-absorbing layer in various optoelectronic devices. However, to increase device performance for wider adoption, it is essential to find innovative solutions. One promising solution is incorporating carbon nanotubes [...] Read more.

Due to their exceptional optoelectronic properties, halide perovskites have emerged as prominent materials for the light-absorbing layer in various optoelectronic devices. However, to increase device performance for wider adoption, it is essential to find innovative solutions. One promising solution is incorporating carbon nanotubes (CNTs), which have shown remarkable versatility and efficacy. In these devices, CNTs serve multiple functions, including providing conducting substrates and electrodes and improving charge extraction and transport. The next iteration of photovoltaic devices, metal halide perovskite solar cells (PSCs), holds immense promise. Despite significant progress, achieving optimal efficiency, stability, and affordability simultaneously remains a challenge, and overcoming these obstacles requires the development of novel materials known as CNTs, which, owing to their remarkable electrical, optical, and mechanical properties, have garnered considerable attention as potential materials for highly efficient PSCs. Incorporating CNTs into perovskite solar cells offers versatility, enabling improvements in device performance and longevity while catering to diverse applications. This article provides an in-depth exploration of recent advancements in carbon nanotube technology and its integration into perovskite solar cells, serving as transparent conductive electrodes, charge transporters, interlayers, hole-transporting materials, and back electrodes. Additionally, we highlighted key challenges and offered insights for future enhancements in perovskite solar cells leveraging CNTs. Full article

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20 pages, 7328 KiB

Open AccessReview

Chiral Materials for Optics and Electronics: Ready to Rise?

by Seo-Hyeon Ham, Moon Jong Han and Minkyu Kim

Micromachines 2024, 15(4), 528; https://doi.org/10.3390/mi15040528 - 15 Apr 2024

Cited by 1 | Viewed by 2194

Abstract

Chiral materials have gained burgeoning interest in optics and electronics, beyond their classical application field of drug synthesis. In this review, we summarize the diverse chiral materials developed to date and how they have been effectively applied to optics and electronics to get [...] Read more.

Chiral materials have gained burgeoning interest in optics and electronics, beyond their classical application field of drug synthesis. In this review, we summarize the diverse chiral materials developed to date and how they have been effectively applied to optics and electronics to get an understanding and vision for the further development of chiral materials for advanced optics and electronics. Full article

(This article belongs to the Special Issue Feature Papers of Micromachines in 'Materials and Processing' 2024)

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14 pages, 6292 KiB

Open AccessArticle

The Study on Single-Event Effects and Hardening Analysis of Frequency Divider Circuits Based on InP HBT Process

by Xiaohong Zhao, Yongbo Su, You Chen, Yihao Zhang, Jianjun Xiang, Siyi Cheng and Yurong Bai

Micromachines 2024, 15(4), 527; https://doi.org/10.3390/mi15040527 - 15 Apr 2024

Viewed by 1027

Abstract

The single-event effects (SEEs) of frequency divider circuits and the radiation tolerance of the hardened circuit are studied in this paper. Based on the experimental results of SEEs in InP HBTs, a transient current model for sensitive transistors is established, taking into account [...] Read more.

The single-event effects (SEEs) of frequency divider circuits and the radiation tolerance of the hardened circuit are studied in this paper. Based on the experimental results of SEEs in InP HBTs, a transient current model for sensitive transistors is established, taking into account the influence of factors such as laser energy, base-collector junction voltage, and radiation position. Moreover, the SEEs of the (2:1) static frequency divider circuit with the InP DHBT process are simulated under different laser energies by adding the transient current model at sensitive nodes. The effect of the time relationship between the pulsed laser and clock signal are discussed. Changes in differential output voltage and the degradation mechanism of unhardened circuits are analyzed, which are mainly attributed to the cross-coupling effect between the transistors in the differential pair. Furthermore, the inverted output is directly connected to the input, leading to a feedback loop and causing significant logic upsets. Finally, an effective hardened method is proposed to provide redundancy and mitigate the impacts of SEEs on the divider. The simulation results demonstrate a notable improvement in the radiation tolerance of the divider. Full article

(This article belongs to the Special Issue High-Reliability Semiconductor Devices and Integrated Circuits, 2nd Edition)

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22 pages, 21562 KiB

Open AccessArticle

Compliance and Kinetostatics of a Novel 2PRS-2PSS Compliant Parallel Micromanipulator: Modeling and Analysis

by Jun Ren and Hui Jiang

Micromachines 2024, 15(4), 526; https://doi.org/10.3390/mi15040526 - 14 Apr 2024

Viewed by 1255

Abstract

A novel 2PRS-2PSS (P represents the prismatic pair, R represents the revolute hinge, S represents the spherical hinge) compliant parallel micromanipulator with two translational DOFs and two rotational DOFs is presented, and its compliance model and kinetostatic model are sequentially developed and analyzed. [...] Read more.

A novel 2PRS-2PSS (P represents the prismatic pair, R represents the revolute hinge, S represents the spherical hinge) compliant parallel micromanipulator with two translational DOFs and two rotational DOFs is presented, and its compliance model and kinetostatic model are sequentially developed and analyzed. Initially, an analytical model used to describe the compliance of this micromanipulator was developed using the compliance matrix method (CMM). Through a comparison with finite element analysis, the accuracy of this analytical model is confirmed, and the influence of various dimensional and structural parameters on the compliance behavior is investigated. Subsequently, the micromanipulator is treated as an equivalent spring system, allowing for the derivation of its governing equation based on the established compliance model. From this equation, a kinetostatic model relating input forces to output displacements is derived. Validation of this model is performed by comparing analytical results with finite element simulations under specific motion trajectories, revealing a maximum relative error of 6.18%. This close agreement verifies the accuracy of the kinetostatic model. Finally, the impact of the parameters of the flexure hinge on the mapping matrix is examined to offer insights into minimizing undesired displacements, providing valuable guidance for optimizing the micromanipulator’s performance. Full article

(This article belongs to the Special Issue Advanced Micro-/Nano-Manipulation and Positioning Techniques)

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20 pages, 6208 KiB

Open AccessArticle

Impact of Ceramic Micropillar Array and Fiber Layer Composite Structure on Kinematic and Heat Transfer Characteristics of Single Droplet Impacting a Wall

by Dechao Zhang, Guangjing Zhang, Yiwei Li, Yaobin Jiang and Yusong Yu

Micromachines 2024, 15(4), 525; https://doi.org/10.3390/mi15040525 - 14 Apr 2024

Viewed by 992

Abstract

The well-known limitations of spray cooling on high-temperature solids at the Leidenfrost temperature point have been significantly improved by a composite structure of steel micropillar arrays and insulating thin films. However, the physical mechanism of a single droplet impact on the walls of [...] Read more.

The well-known limitations of spray cooling on high-temperature solids at the Leidenfrost temperature point have been significantly improved by a composite structure of steel micropillar arrays and insulating thin films. However, the physical mechanism of a single droplet impact on the walls of high-temperature composite structures in spray cooling remains elusive. We have experimentally studied and quantified the kinematic and thermal transfer characteristics of a single droplet impacting high-temperature micropillar arrays with fiber membrane composite structures. In particular, micropillar arrays of ceramic materials of different shapes (rectangular and cylindrical) used in this study were made using the more flexible PμSL technique, for which precision reaches the micron level. The results show that the presence and different layouts (embedded or placed on top) of the fiber layer significantly affect the spreading coefficient and thermal transfer efficiency of the droplets after impact. In terms of kinematic characteristics, unrelated to the structure of micropillar arrays, compared to structures without film, the maximum spreading coefficient of droplets significantly increased by more than 40% (43% for rectangular, 46% for cylindrical) when the fiber film was placed on top, and increased by more than 20% (20% for rectangular, 33% for cylindrical) when the fiber film was embedded. In terms of thermal transfer characteristics, at a temperature of 200 °C, the presence of the fiber layer changed the wettability of the surface of the micropillar structure, leading to a certain extension of the total evaporation time of the droplets compared to the surface of the micropillar structure without film. Full article

(This article belongs to the Section D3: 3D Printing and Additive Manufacturing)

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