Micro and Nano Engineering最新文献_第4页

Side-wall metallization process for enhanced electrical contact in SOI-based MEMS switches 基于soi的MEMS开关中增强电接触的侧壁金属化工艺

IF 3.1 Q2 ENGINEERING, ELECTRICAL & ELECTRONIC

Micro and Nano Engineering

Pub Date : 2025-12-01 Epub Date: 2025-11-17 DOI: 10.1016/j.mne.2025.100338

Inês S. Garcia , Filipa C. Mota , Jorge M. Pereira , Fahimullah Khan , Carlos Ferreira , Jorge Cabral , José Fernandes , Carlos Calaza , Rosana A. Dias , Filipe S. Alves

MEMS inertial switches provide a zero-power alternative to conventional accelerometers by mechanically closing an electrical contact only when a specific acceleration threshold is exceeded. However, conventional SOI-based MEMS switches suffer from high silicon-to‑silicon contact resistance, which degrades signal reliability and limits device performance. This work presents a novel fabrication process that enables selective metal coating of contact side-wall in SOI-based MEMS inertial switches, aiming to reduce contact resistance while maintaining compatibility with standard MEMS bulk micromachining process flows. The proposed method introduces a pre-release metallization sequence combining deep reactive ion etching (DRIE), EKC-based cleaning, directional sputtering of an aluminum alloy, and a photosensitive polyimide (PI) masking process, followed by chemical mechanical planarization (CMP). This integration eliminates the need for post-release processing or dry-film resists and ensures alignment with SOI process constraints. Optical and scanning electron microscopy (SEM) inspection confirmed proper pattern transfer, trench formation, and planarization, while energy-dispersive X-ray spectroscopy (EDX) analysis revealed partial side-wall metal coverage, predominantly on upper regions due to shadowing effects induced by DRIE scalloping. Electrical measurements demonstrated a reduction in contact resistance from over 3 kΩ to 200 Ω in metallized areas. Although out-of-plane misalignment between electrodes (≈250 nm) limited reliable AlAl contact formation, the demonstrated process provides a scalable approach to create low-resistance contacts in bulk-micromachined MEMS switches and establishes a foundation for future optimization through thicker or alternative metal depositions.

MEMS惯性开关仅在超过特定加速度阈值时机械关闭电触点，从而为传统加速度计提供零功率替代方案。然而，传统的基于soi的MEMS开关存在高硅对硅接触电阻，这会降低信号可靠性并限制器件性能。这项工作提出了一种新的制造工艺，可以在基于soi的MEMS惯性开关的接触侧壁上选择性地涂覆金属，旨在降低接触电阻，同时保持与标准MEMS体微加工工艺流程的兼容性。该方法引入了一种预释放金属化序列，包括深度反应离子蚀刻（DRIE）、基于ekc的清洗、铝合金的定向溅射和光敏聚酰亚胺（PI）掩蔽工艺，然后是化学机械平面化（CMP）。这种集成消除了对释放后处理或干膜抗蚀剂的需要，并确保与SOI工艺约束保持一致。光学和扫描电子显微镜（SEM）检查证实了适当的模式转移、沟槽形成和平面化，而能量色散x射线光谱（EDX）分析显示了部分侧壁金属覆盖，主要是由于DRIE扇贝引起的阴影效应在上部区域。电学测量表明，在金属化区域，接触电阻从3 kΩ以上降低到200 Ω。虽然电极之间的面外错位（≈250 nm）限制了可靠的AlAl触点形成，但所演示的工艺提供了一种可扩展的方法，可以在大块微机械MEMS开关中创建低电阻触点，并为未来通过更厚或替代金属沉积进行优化奠定了基础。

{"title":"Side-wall metallization process for enhanced electrical contact in SOI-based MEMS switches","authors":"Inês S. Garcia , Filipa C. Mota , Jorge M. Pereira , Fahimullah Khan , Carlos Ferreira , Jorge Cabral , José Fernandes , Carlos Calaza , Rosana A. Dias , Filipe S. Alves","doi":"10.1016/j.mne.2025.100338","DOIUrl":"10.1016/j.mne.2025.100338","url":null,"abstract":"<div><div>MEMS inertial switches provide a zero-power alternative to conventional accelerometers by mechanically closing an electrical contact only when a specific acceleration threshold is exceeded. However, conventional SOI-based MEMS switches suffer from high silicon-to‑silicon contact resistance, which degrades signal reliability and limits device performance. This work presents a novel fabrication process that enables selective metal coating of contact side-wall in SOI-based MEMS inertial switches, aiming to reduce contact resistance while maintaining compatibility with standard MEMS bulk micromachining process flows. The proposed method introduces a pre-release metallization sequence combining deep reactive ion etching (DRIE), EKC-based cleaning, directional sputtering of an aluminum alloy, and a photosensitive polyimide (PI) masking process, followed by chemical mechanical planarization (CMP). This integration eliminates the need for post-release processing or dry-film resists and ensures alignment with SOI process constraints. Optical and scanning electron microscopy (SEM) inspection confirmed proper pattern transfer, trench formation, and planarization, while energy-dispersive X-ray spectroscopy (EDX) analysis revealed partial side-wall metal coverage, predominantly on upper regions due to shadowing effects induced by DRIE scalloping. Electrical measurements demonstrated a reduction in contact resistance from over 3 kΩ to 200 Ω in metallized areas. Although out-of-plane misalignment between electrodes (≈250 nm) limited reliable Al<img>Al contact formation, the demonstrated process provides a scalable approach to create low-resistance contacts in bulk-micromachined MEMS switches and establishes a foundation for future optimization through thicker or alternative metal depositions.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"29 ","pages":"Article 100338"},"PeriodicalIF":3.1,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145575917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Impact of cavity shape on thermal accelerometer parameters 空腔形状对热加速度计参数的影响

IF 3.1 Q2 ENGINEERING, ELECTRICAL & ELECTRONIC

Micro and Nano Engineering

Pub Date : 2025-12-01 Epub Date: 2025-11-13 DOI: 10.1016/j.mne.2025.100331

Toulmé Valentin , Ben Salk Soukaina , Faucher Marc , Combette Philippe , Giani Alain

This publication examines CFD (Computational Fluid Dynamics) analyses of a uniaxial accelerometer's behavior, focusing on convective heat transfer. A thermal convective accelerometer is a sensor that employs hot wire technology to quantify acceleration. The analytical modelling of sensitivity is inadequate for predicting sensitivity evolution as a function of acceleration in complex scenarios, particularly in temporal investigations; hence, CFD simulations have been employed. The sensitivity dependent on the sensor's form has been examined through simulations for accelerations exceeding 100,000 g. Furthermore, the bandwidth of the thermal accelerometer has been studied under various setups. The outcomes of these simulations will enhance sensor performance (cavity and wire dimensions, spacing between detectors and heater) to attain a measurement range of 100,000 g and a bandwidth of 10 kHz.

本出版物研究了单轴加速度计行为的CFD（计算流体动力学）分析，重点是对流传热。热对流加速度计是一种采用热丝技术来量化加速度的传感器。敏感性的分析模型不足以预测在复杂情况下，特别是在时间调查中，敏感性作为加速度的函数的演变；因此，采用CFD模拟。灵敏度依赖于传感器的形式已经通过模拟超过100,000 g的加速度进行了检查。此外，还研究了热加速度计在不同设置下的带宽。这些模拟的结果将提高传感器的性能（腔和导线尺寸，探测器和加热器之间的间距），以达到100,000 g的测量范围和10 kHz的带宽。

引用次数: 0

Review of plasma etching processes for III-V semiconductors III-V型半导体等离子体刻蚀工艺研究进展

IF 3.1 Q2 ENGINEERING, ELECTRICAL & ELECTRONIC

Micro and Nano Engineering

Pub Date : 2025-12-01 Epub Date: 2025-11-11 DOI: 10.1016/j.mne.2025.100330

Alison Clarke , Maxime Darnon , Karin Hinzer , Mathieu de Lafontaine

This paper provides a comprehensive literature review and analysis of III-V semiconductor plasma etching, highlighting key etching considerations and providing literature references to inform future process development. Plasma etching processes for III-V materials such as gallium arsenide (GaAs), indium phosphide (InP), and gallium nitride (GaN) are essential to fabricate many photonic and optoelectronic devices. Such applications frequently require etches with high anisotropy, selectivity and aspect ratio while maintaining minimal roughness and lateral etching. Ten plasma etching techniques used for III-V materials as well as the impact of plasma process parameters on etch results are reviewed. Main etching challenges include aluminum oxidation, non-volatile indium etch subproducts when

<

150 °C, and strong III-N bonds. Exhaustive reference tables are generated to report capacitively coupled plasma (CCP) and inductively coupled plasma (ICP) etching process parameters for the main binary, ternary, and quaternary III-V semiconductors. An analysis of binary III-V etching is presented in a summative reference plot, which highlights trends in etch rate, etch technology, and active gas chemistry. Among studies reporting etch rates, gallium arsenide was etched most frequently, with ICP being the dominant etch technique. Multilayer systems and plasma damage are briefly discussed, with post-etch treatments and hydrogen plasmas being used for damage passivation. Overall, III-V materials can be etched with plasma up to several

μ

m/min, with most processes using chlorine-based chemistries such as Cl

_{2}

, BCl

_{3}

, and SiCl

_{4}

.

本文对III-V型半导体等离子体刻蚀进行了全面的文献综述和分析，强调了刻蚀的关键注意事项，并为未来的工艺发展提供了文献参考。砷化镓（GaAs）、磷化铟（InP）和氮化镓（GaN）等III-V材料的等离子体刻蚀工艺对于制造许多光子和光电器件至关重要。此类应用通常需要具有高各向异性，选择性和纵横比的蚀刻，同时保持最小的粗糙度和横向蚀刻。综述了十种用于III-V材料的等离子体刻蚀技术以及等离子体工艺参数对刻蚀结果的影响。主要的蚀刻挑战包括铝氧化，150°C时的非挥发性铟蚀刻子产品，以及强III-N键。详尽的参考表生成报告电容耦合等离子体（CCP）和电感耦合等离子体（ICP）蚀刻工艺参数的主要二元，三元和四元III-V半导体。在总结参考图中对二元III-V刻蚀进行了分析，重点介绍了刻蚀速率，刻蚀技术和活性气体化学的趋势。在报告蚀刻率的研究中，砷化镓蚀刻最频繁，ICP是主要的蚀刻技术。本文对多层体系和等离子体损伤进行了简要的讨论，并利用刻蚀后处理和氢等离子体进行损伤钝化。总体而言，III-V材料可以用高达几μm/min的等离子体蚀刻，大多数工艺使用氯基化学物质，如Cl2， BCl3和SiCl4。

{"title":"Review of plasma etching processes for III-V semiconductors","authors":"Alison Clarke , Maxime Darnon , Karin Hinzer , Mathieu de Lafontaine","doi":"10.1016/j.mne.2025.100330","DOIUrl":"10.1016/j.mne.2025.100330","url":null,"abstract":"<div><div>This paper provides a comprehensive literature review and analysis of III-V semiconductor plasma etching, highlighting key etching considerations and providing literature references to inform future process development. Plasma etching processes for III-V materials such as gallium arsenide (GaAs), indium phosphide (InP), and gallium nitride (GaN) are essential to fabricate many photonic and optoelectronic devices. Such applications frequently require etches with high anisotropy, selectivity and aspect ratio while maintaining minimal roughness and lateral etching. Ten plasma etching techniques used for III-V materials as well as the impact of plasma process parameters on etch results are reviewed. Main etching challenges include aluminum oxidation, non-volatile indium etch subproducts when <span><math><mo><</mo></math></span>150 °C, and strong III-N bonds. Exhaustive reference tables are generated to report capacitively coupled plasma (CCP) and inductively coupled plasma (ICP) etching process parameters for the main binary, ternary, and quaternary III-V semiconductors. An analysis of binary III-V etching is presented in a summative reference plot, which highlights trends in etch rate, etch technology, and active gas chemistry. Among studies reporting etch rates, gallium arsenide was etched most frequently, with ICP being the dominant etch technique. Multilayer systems and plasma damage are briefly discussed, with post-etch treatments and hydrogen plasmas being used for damage passivation. Overall, III-V materials can be etched with plasma up to several <span><math><mi>μ</mi></math></span>m/min, with most processes using chlorine-based chemistries such as Cl<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, BCl<span><math><msub><mrow></mrow><mrow><mn>3</mn></mrow></msub></math></span>, and SiCl<span><math><msub><mrow></mrow><mrow><mn>4</mn></mrow></msub></math></span>.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"29 ","pages":"Article 100330"},"PeriodicalIF":3.1,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145575914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

The comparison of NH3 and N2O plasma treatments on PZT Lead zirconate titanate sensing membranes applied in biosensor NH3和N2O等离子体处理在PZT锆钛酸铅传感膜上的应用比较

IF 3.1 Q2 ENGINEERING, ELECTRICAL & ELECTRONIC

Micro and Nano Engineering

Pub Date : 2025-12-01 Epub Date: 2025-11-15 DOI: 10.1016/j.mne.2025.100334

Ming Ling Lee, Sung Hao Li

This study conducted a comparative analysis of NH3 and N₂O plasma treatments on PZT (lead zirconate titanate, Pb(Zr_0.52Ti_0.48)O₃) sensing membranes integrated within the EIS (Electrolyte-Insulator-Semiconductor) structure. PZT sensing membranes subjected to NH₃ and N₂O plasma treatments were examined using multiple material analysis techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The PZT sensing membrane treated with N₂O plasma for 1 min exhibited the highest sensitivity, superior linearity, lowest hysteresis voltage, and minimal drift rate compared to the other N₂O plasma conditions. Likewise, the PZT sensing membrane treated with NH₃ plasma for 6 min demonstrated the highest sensitivity, optimal linearity, excellent H⁺ selectivity, lowest hysteresis voltage, and least drift rate among the various plasma conditions. Additionally, we investigated the biomedical sensing characteristics of PZT sensing membranes in urea, creatinine, and glucose solutions. Measurements revealed that PZT sensing membranes exhibited optimal sensing characteristics for urea, creatinine, and glucose when subjected to a 6-min exposure to ammonia plasma. Notably, the sensing membrane demonstrated the best sensitivity and linearity for glucose, with values of 15.5 mV/mM and 98.49 %, respectively. These results highlight that the PZT sensing membrane, following plasma treatment within the EIS structure, is well-suited for applications in biomedical devices.

本研究对比分析了NH3和N2O等离子体处理对集成在EIS（电解质-绝缘体-半导体）结构内的PZT（锆钛酸铅，Pb(Zr0.52Ti0.48)O3）传感膜的影响。采用多种材料分析技术，包括x射线衍射（XRD）、x射线光电子能谱（XPS）和原子力显微镜（AFM），对经过NH3和N2O等离子体处理的PZT传感膜进行了检测。与其他N2O等离子体条件相比，经N2O等离子体处理1 min的PZT传感膜具有最高的灵敏度、良好的线性度、最低的滞后电压和最小的漂移率。同样，在不同的等离子体条件下，经过NH3等离子体处理6 min的PZT传感膜表现出最高的灵敏度、最佳的线性度、优异的H+选择性、最低的滞后电压和最小的漂移率。此外，我们还研究了PZT传感膜在尿素、肌酐和葡萄糖溶液中的生物医学传感特性。测量结果显示，PZT传感膜在暴露于氨血浆6分钟时，对尿素、肌酐和葡萄糖表现出最佳的传感特性。值得注意的是，该传感膜对葡萄糖的灵敏度和线性度最高，分别为15.5 mV/mM和98.49%。这些结果表明，在EIS结构内进行等离子体处理的PZT传感膜非常适合应用于生物医学设备。

{"title":"The comparison of NH3 and N2O plasma treatments on PZT Lead zirconate titanate sensing membranes applied in biosensor","authors":"Ming Ling Lee, Sung Hao Li","doi":"10.1016/j.mne.2025.100334","DOIUrl":"10.1016/j.mne.2025.100334","url":null,"abstract":"<div><div>This study conducted a comparative analysis of NH3 and N<sub>2</sub>O plasma treatments on PZT (lead zirconate titanate, Pb(Zr<sub>0.52</sub>Ti<sub>0.48</sub>)O<sub>3</sub>) sensing membranes integrated within the EIS (Electrolyte-Insulator-Semiconductor) structure. PZT sensing membranes subjected to NH<sub>3</sub> and N<sub>2</sub>O plasma treatments were examined using multiple material analysis techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and atomic force microscopy (AFM). The PZT sensing membrane treated with N<sub>2</sub>O plasma for 1 min exhibited the highest sensitivity, superior linearity, lowest hysteresis voltage, and minimal drift rate compared to the other N<sub>2</sub>O plasma conditions. Likewise, the PZT sensing membrane treated with NH<sub>3</sub> plasma for 6 min demonstrated the highest sensitivity, optimal linearity, excellent H<sup>+</sup> selectivity, lowest hysteresis voltage, and least drift rate among the various plasma conditions. Additionally, we investigated the biomedical sensing characteristics of PZT sensing membranes in urea, creatinine, and glucose solutions. Measurements revealed that PZT sensing membranes exhibited optimal sensing characteristics for urea, creatinine, and glucose when subjected to a 6-min exposure to ammonia plasma. Notably, the sensing membrane demonstrated the best sensitivity and linearity for glucose, with values of 15.5 mV/mM and 98.49 %, respectively. These results highlight that the PZT sensing membrane, following plasma treatment within the EIS structure, is well-suited for applications in biomedical devices.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"29 ","pages":"Article 100334"},"PeriodicalIF":3.1,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145575915","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Evaluation of annealing effects on the deformation of Ti/Au multi-layered micro-cantilevers 退火对Ti/Au多层微悬臂梁变形的影响

IF 3.1 Q2 ENGINEERING, ELECTRICAL & ELECTRONIC

Micro and Nano Engineering

Pub Date : 2025-12-01 Epub Date: 2025-11-09 DOI: 10.1016/j.mne.2025.100333

Ryosuke Miyai , Tomoyuki Kurioka , Chun-Yi Chen , Tso-Fu Mark Chang , Katsuyuki Machida , Hiroyuki Ito , Yoshihiro Miyake , Masato Sone

This paper reports the effects of annealing on the deformation behavior of Ti/Au multi-layered micro-cantilevers. A total of 72 Ti/Au multi-layered micro-cantilevers with different geometric parameters are fabricated. The annealing temperature up to 200 °C hardly causes their deformation, while the annealing performed at temperatures higher than 200 °C induces the deformation of the micro-cantilevers with thinner beam thickness. Auger electron spectroscopy measurements for the electrodeposited-Au components subjected to annealing at different temperatures suggest that the observed deformation is partially due to the diffusion of titanium and oxygen atoms induced by the annealing.

本文报道了退火对Ti/Au多层微悬臂梁变形行为的影响。共制备了72根不同几何参数的Ti/Au多层微悬臂梁。当退火温度达到200℃时，微悬臂梁几乎不发生变形，而当退火温度高于200℃时，微悬臂梁的梁厚较薄，微悬臂梁发生变形。对在不同温度下退火的电沉积金元件进行的俄歇电子能谱测量表明，观察到的变形部分是由于退火引起的钛原子和氧原子的扩散。

引用次数: 0

Scalability analysis for transmon-based quantum computers 基于transmon的量子计算机的可扩展性分析

IF 3.1 Q2 ENGINEERING, ELECTRICAL & ELECTRONIC

Micro and Nano Engineering

Pub Date : 2025-12-01 Epub Date: 2025-10-13 DOI: 10.1016/j.mne.2025.100327

Shi-Li Zhang

Quantum computing has been envisioned to offer unprecedented advantages over conventional supercomputers in certain computational applications such as drug discovery and materials design. Despite of the tremendous developments in recent years, concerns about building a practical quantum computer persist. This Letter examines, from engineering viewpoint, the grand challenges to building such a machine based on the leading technology platform “transmon”. The examination leads to proposal of technological solutions to break the scalability barriers that originate from the physics behind the transmon design, thereby to enable giga-scale integration necessary for the promised applications.

量子计算被设想在某些计算应用中提供比传统超级计算机前所未有的优势，例如药物发现和材料设计。尽管近年来取得了巨大的发展，但对建造实用量子计算机的担忧仍然存在。这封信从工程的角度考察了基于领先的技术平台“transmon”建造这样一台机器的巨大挑战。通过这项研究，我们提出了一些技术解决方案，以打破来自transmon设计背后的物理的可伸缩性障碍，从而实现所承诺的应用程序所必需的千兆级集成。

引用次数: 0

3D-printed piezoelectrically-actuated self-sensing cantilever for contact resonance 用于接触共振的3d打印压电驱动自传感悬臂

IF 3.1 Q2 ENGINEERING, ELECTRICAL & ELECTRONIC

Micro and Nano Engineering

Pub Date : 2025-12-01 Epub Date: 2025-11-09 DOI: 10.1016/j.mne.2025.100335

Enrique Sánchez-Gómez, Víctor Ruiz-Díez, Jorge Hernando-García

The assessment of mechanical properties is essential across a wide range of scientific and engineering disciplines. Among the available techniques, contact resonance stands out for its sensitivity and resolution. Traditionally associated with atomic force microscopy, this method operates in the nanonewton force range using nanometer-scale tip radii and relies on complex optical detection systems. However, applications involving biological materials, such as plant tissues, might require higher forces, typically in the micronewton range, and larger indenters at the micron scale to minimize local stress. In this work, we present a contact resonance system based on 3D-printed cantilevers designed to operate at micronewton force levels. Both actuation and detection of vibrational modes are achieved using piezoelectric materials, enabling a fully electrical setup that eliminates the need for optical components. The indenters are fabricated from tungsten via electrochemical etching, allowing precise control over tip geometry at the micrometer scale. The system successfully detects frequency shifts upon contact with materials exhibiting elastic moduli from a few to several tens of gigapascals, offering a versatile and cost-effective alternative for mechanical property evaluation.

机械性能的评估在广泛的科学和工程学科中是必不可少的。在现有的技术中，接触共振以其灵敏度和分辨率而脱颖而出。传统上与原子力显微镜相关，该方法使用纳米尺度的尖端半径在纳米牛顿力范围内操作，并依赖于复杂的光学检测系统。然而，涉及生物材料（如植物组织）的应用可能需要更高的力，通常在微牛顿范围内，并且在微米尺度上需要更大的压头以最小化局部应力。在这项工作中，我们提出了一种基于3d打印悬臂梁的接触共振系统，设计用于微牛顿力水平。振动模式的驱动和检测都是使用压电材料实现的，从而实现了完全的电气设置，从而消除了对光学元件的需求。压头由钨通过电化学蚀刻制成，允许在微米尺度上精确控制尖端几何形状。该系统成功地检测到材料接触时的频率变化，其弹性模量从几到几十千兆帕斯卡，为机械性能评估提供了一种多功能且经济高效的替代方案。

{"title":"3D-printed piezoelectrically-actuated self-sensing cantilever for contact resonance","authors":"Enrique Sánchez-Gómez, Víctor Ruiz-Díez, Jorge Hernando-García","doi":"10.1016/j.mne.2025.100335","DOIUrl":"10.1016/j.mne.2025.100335","url":null,"abstract":"<div><div>The assessment of mechanical properties is essential across a wide range of scientific and engineering disciplines. Among the available techniques, contact resonance stands out for its sensitivity and resolution. Traditionally associated with atomic force microscopy, this method operates in the nanonewton force range using nanometer-scale tip radii and relies on complex optical detection systems. However, applications involving biological materials, such as plant tissues, might require higher forces, typically in the micronewton range, and larger indenters at the micron scale to minimize local stress. In this work, we present a contact resonance system based on 3D-printed cantilevers designed to operate at micronewton force levels. Both actuation and detection of vibrational modes are achieved using piezoelectric materials, enabling a fully electrical setup that eliminates the need for optical components. The indenters are fabricated from tungsten via electrochemical etching, allowing precise control over tip geometry at the micrometer scale. The system successfully detects frequency shifts upon contact with materials exhibiting elastic moduli from a few to several tens of gigapascals, offering a versatile and cost-effective alternative for mechanical property evaluation.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"29 ","pages":"Article 100335"},"PeriodicalIF":3.1,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145525349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Optimization of maskless SU-8 photolithography for fabrication of dense high-aspect-ratio pyrolytic carbon micropillar arrays 无掩膜SU-8光刻技术制备高密度高纵横比热解碳微柱阵列的优化研究

IF 3.1 Q2 ENGINEERING, ELECTRICAL & ELECTRONIC

Micro and Nano Engineering

Pub Date : 2025-12-01 Epub Date: 2025-10-02 DOI: 10.1016/j.mne.2025.100324

Mohammad Ramezannezhad, Babak Rezaei, Stephan Sylvest Keller

This study presents the optimization of maskless UV lithography with SU-8 for the fabrication of 3D electrodes with pyrolytic carbon micropillar arrays. The aim was to maximize the pillar density and enhance the electroactive surface area of the electrodes. For this purpose, the exposure dose at 365 nm wavelength and defocus value in a maskless aligner projecting the image with a spatial light modulator onto the substrate were optimized for fabrication of SU-8 micropillars with heights varying from 25 to 100 μm and diameters ranging from 5 to 40 μm resulting in aspect-ratio of up to 10. The minimal achievable gap in SU-8 micropillar arrays was largely dependent on the defocus value, and gap dimensions identical to the pillar diameter were achieved. The SU-8 precursor structures were successfully converted into carbon micropillar arrays by pyrolysis at 1050 °C with an observed shrinkage of approximately 50 %. 3D carbon microelectrodes were fabricated and electrochemically characterized with cyclic voltammetry and electrochemical impedance spectroscopy. The results indicate that there is a reasonable correlation between microelectrode surface area and electrochemical performance of the electrodes. 3D electrodes with less dense arrays of larger pillars fabricated with initial SU-8 height of 75 μm and 100 μm showed higher peak currents in cyclic voltammetry than smaller pillars at higher number densities, reaching a maximum enhancement of approximately a factor 2 compared to 2D electrodes without micropillars.

本研究提出了SU-8无掩膜UV光刻技术的优化，用于制备热解碳微柱阵列三维电极。目的是最大限度地提高柱密度和提高电极的电活性表面积。为此，优化了365 nm波长下的曝光剂量和利用空间光调制器将图像投射到衬底上的无掩模对准器的离焦值，以制备高度为25 ~ 100 μm、直径为5 ~ 40 μm的SU-8微柱，其宽高比可达10。SU-8微柱阵列可实现的最小间隙在很大程度上取决于离焦值，并且可以实现与柱直径相同的间隙尺寸。SU-8前驱体结构在1050℃下成功转化为碳微柱阵列，观察到收缩率约为50%。采用循环伏安法和电化学阻抗法对三维碳微电极进行了电化学表征。结果表明，微电极表面积与电极的电化学性能之间存在着合理的相关性。在SU-8初始高度为75 μm和100 μm的情况下，采用密度较小的大柱阵列的3D电极在循环伏安法中显示出比小柱更高的峰值电流，与没有微柱的2D电极相比，其最大增强幅度约为2倍。

{"title":"Optimization of maskless SU-8 photolithography for fabrication of dense high-aspect-ratio pyrolytic carbon micropillar arrays","authors":"Mohammad Ramezannezhad, Babak Rezaei, Stephan Sylvest Keller","doi":"10.1016/j.mne.2025.100324","DOIUrl":"10.1016/j.mne.2025.100324","url":null,"abstract":"<div><div>This study presents the optimization of maskless UV lithography with SU-8 for the fabrication of 3D electrodes with pyrolytic carbon micropillar arrays. The aim was to maximize the pillar density and enhance the electroactive surface area of the electrodes. For this purpose, the exposure dose at 365 nm wavelength and defocus value in a maskless aligner projecting the image with a spatial light modulator onto the substrate were optimized for fabrication of SU-8 micropillars with heights varying from 25 to 100 μm and diameters ranging from 5 to 40 μm resulting in aspect-ratio of up to 10. The minimal achievable gap in SU-8 micropillar arrays was largely dependent on the defocus value, and gap dimensions identical to the pillar diameter were achieved. The SU-8 precursor structures were successfully converted into carbon micropillar arrays by pyrolysis at 1050 °C with an observed shrinkage of approximately 50 %. 3D carbon microelectrodes were fabricated and electrochemically characterized with cyclic voltammetry and electrochemical impedance spectroscopy. The results indicate that there is a reasonable correlation between microelectrode surface area and electrochemical performance of the electrodes. 3D electrodes with less dense arrays of larger pillars fabricated with initial SU-8 height of 75 μm and 100 μm showed higher peak currents in cyclic voltammetry than smaller pillars at higher number densities, reaching a maximum enhancement of approximately a factor 2 compared to 2D electrodes without micropillars.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"29 ","pages":"Article 100324"},"PeriodicalIF":3.1,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145269212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Anisotropic reactive ion etching of 2.5 micrometer thick alpha phase tantalum films for surface micromachining 2.5微米厚α相钽薄膜表面微加工的各向异性反应离子刻蚀

IF 2.8 Q2 ENGINEERING, ELECTRICAL & ELECTRONIC

Micro and Nano Engineering

Pub Date : 2025-09-01 Epub Date: 2025-06-23 DOI: 10.1016/j.mne.2025.100305

Md Shariful Islam, Longchang Ni, Maarten P. de Boer

An etch parameter study is conducted with the objective of achieving high anisotropy for tantalum (Ta) thin films of more than 1 μm in thickness. The gases explored are Argon (Ar), carbon tetrafluoride (CF₄) and oxygen. The effects of composition, flow, pressure, and power are investigated. Optical emission spectroscopy is used to interpret the etch results. While the addition of oxygen adversely affects anisotropy, it is improved with lower pressure. An Ar:CF₄ ratio of 5:1 is found to enable good etch rate and sidewall passivation. As power increases, the etch rate increases but there is no observable enhancement in anisotropy. Using a common parallel-plate RIE configuration with common low toxicity gases, a vertical sidewall is achieved for 2.5 μm thick

α

-Ta films with an optimum Ar to CF₄ ratio, power and pressure.

为了实现厚度大于1 μm的钽（Ta）薄膜的高各向异性，对其蚀刻参数进行了研究。探测到的气体是氩（Ar）、四氟化碳（CF4）和氧。研究了组分、流量、压力和功率的影响。光学发射光谱用于解释蚀刻结果。虽然氧的加入对各向异性有不利影响，但在较低的压力下，各向异性得到改善。发现Ar:CF4比为5:1可以实现良好的蚀刻速率和侧壁钝化。随着功率的增加，腐蚀速率增加，但各向异性没有明显的增强。采用常见的平行板RIE结构和常见的低毒性气体，在最佳的Ar / CF4比、功率和压力下，获得了2.5 μm厚α-Ta膜的垂直侧壁。

引用次数: 0

Micro-digital light processing of conventional and hollow Gyroid mesoscale hydrogel scaffolds for neural cell cultures 神经细胞培养用常规和空心陀螺中尺度水凝胶支架的微数字光处理

IF 3.1 Q2 ENGINEERING, ELECTRICAL & ELECTRONIC

Micro and Nano Engineering

Pub Date : 2025-09-01 Epub Date: 2025-08-05 DOI: 10.1016/j.mne.2025.100310

P.F.J. van Altena , L. Castillo Ransanz , M. Manco , V.M. Heine , A. Accardo

Here, we report a high-resolution micro-digital light processing (μDLP) 3D printing protocol for fabricating soft hydrogel scaffolds featuring mesoscale millimetre-sized gyroid-based architectures tailored for 3D neural cell culture. The developed bioink formulation combines poly(ethylene glycol) diacrylate (PEGDA), as the structural backbone, and gelatin methacryloyl (GelMA), to enhance biocompatibility and promote cell adhesion via arginylglycylaspartic acid (RGD) motifs. By combining lithium phenyl (2,4,6-trimethylbenzoyl) phosphinate (LAP) as photoinitiator, along with tartrazine as photoabsorber, we achieved feature sizes down to 12.4 μm with high printing fidelity, reproducibility, and mechanical stability. The mechanical properties of the resulting hydrogel structures showed a Young's modulus (YM) in the 770 kPa – 2.25 MPa range, depending on the presence of GelMA, thus very relevant for neural cells (brain YM in the kPa range), along with remarkable biocompatibility (≈80 % cell viability) and good cell adhesion (≈55 % cell coverage). Two scaffold geometries based on triply periodic minimal surface gyroids were developed: a fully porous structure for culturing dissociated neuroepithelial stem cells and a hollow variant designed to host pre-formed neural organoids. Both scaffold types enabled strong cell adhesion and organoid sprouting, thereby demonstrating their suitability for advanced 3D culture systems. The results highlight the potential of μDLP-fabricated hydrogel meso-scale architectures as a platform for neuromechanobiology studies and tissue-mimetic engineering.

在这里，我们报告了一种高分辨率微数字光处理（μDLP） 3D打印方案，用于制造具有中尺度毫米尺寸的基于陀螺仪的结构的软水凝胶支架，用于3D神经细胞培养。所开发的生物墨水配方将聚乙二醇二丙烯酸酯（PEGDA）作为结构骨架和明胶甲基丙烯酰（GelMA）结合在一起，通过精氨酸基甘氨酸（RGD）基元增强生物相容性并促进细胞粘附。通过结合苯基（2,4,6-三甲基苯甲酰）膦酸锂（LAP）作为光引发剂，酒黄作为光吸收剂，我们实现了小至12.4 μm的特征尺寸，具有高打印保真度、再现性和机械稳定性。所得到的水凝胶结构的力学性能显示，杨氏模量（YM）在770 kPa - 2.25 MPa范围内，取决于GelMA的存在，因此与神经细胞非常相关（脑YM在kPa范围内），同时具有显著的生物相容性（≈80%的细胞活力）和良好的细胞粘附性（≈55%的细胞覆盖率）。研究人员开发了两种基于三周期最小表面陀螺仪的支架几何结构：一种是用于培养分离的神经上皮干细胞的全多孔结构，另一种是用于容纳预先形成的神经类器官的空心结构。这两种支架类型都具有很强的细胞粘附性和类器官发芽能力，从而证明了它们适用于先进的3D培养系统。这些结果突出了μ dlp制备的水凝胶中尺度结构作为神经力学生物学研究和组织模拟工程平台的潜力。

{"title":"Micro-digital light processing of conventional and hollow Gyroid mesoscale hydrogel scaffolds for neural cell cultures","authors":"P.F.J. van Altena , L. Castillo Ransanz , M. Manco , V.M. Heine , A. Accardo","doi":"10.1016/j.mne.2025.100310","DOIUrl":"10.1016/j.mne.2025.100310","url":null,"abstract":"<div><div>Here, we report a high-resolution micro-digital light processing (μDLP) 3D printing protocol for fabricating soft hydrogel scaffolds featuring mesoscale millimetre-sized gyroid-based architectures tailored for 3D neural cell culture. The developed bioink formulation combines poly(ethylene glycol) diacrylate (PEGDA), as the structural backbone, and gelatin methacryloyl (GelMA), to enhance biocompatibility and promote cell adhesion via arginylglycylaspartic acid (RGD) motifs. By combining lithium phenyl (2,4,6-trimethylbenzoyl) phosphinate (LAP) as photoinitiator, along with tartrazine as photoabsorber, we achieved feature sizes down to 12.4 μm with high printing fidelity, reproducibility, and mechanical stability. The mechanical properties of the resulting hydrogel structures showed a Young's modulus (YM) in the 770 kPa – 2.25 MPa range, depending on the presence of GelMA, thus very relevant for neural cells (brain YM in the kPa range), along with remarkable biocompatibility (≈80 % cell viability) and good cell adhesion (≈55 % cell coverage). Two scaffold geometries based on triply periodic minimal surface gyroids were developed: a fully porous structure for culturing dissociated neuroepithelial stem cells and a hollow variant designed to host pre-formed neural organoids. Both scaffold types enabled strong cell adhesion and organoid sprouting, thereby demonstrating their suitability for advanced 3D culture systems. The results highlight the potential of μDLP-fabricated hydrogel meso-scale architectures as a platform for neuromechanobiology studies and tissue-mimetic engineering.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"28 ","pages":"Article 100310"},"PeriodicalIF":3.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144781788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0