Micro and Nano Engineering最新文献

{"title":"Optimization of maskless SU-8 photolithography for fabrication of dense high-aspect-ratio pyrolytic carbon micropillar arrays","authors":"Mohammad Ramezannezhad,&nbsp;Babak Rezaei,&nbsp;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}

{"title":"Anisotropic reactive ion etching of 2.5 micrometer thick alpha phase tantalum films for surface micromachining","authors":"Md Shariful Islam,&nbsp;Longchang Ni,&nbsp;Maarten P. de Boer","doi":"10.1016/j.mne.2025.100305","DOIUrl":"10.1016/j.mne.2025.100305","url":null,"abstract":"<div><div>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 <span><math><mo>α</mo></math></span>-Ta films with an optimum Ar to CF₄ ratio, power and pressure.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"28 ","pages":"Article 100305"},"PeriodicalIF":2.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144549878","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}

{"title":"Micro-digital light processing of conventional and hollow Gyroid mesoscale hydrogel scaffolds for neural cell cultures","authors":"P.F.J. van Altena ,&nbsp;L. Castillo Ransanz ,&nbsp;M. Manco ,&nbsp;V.M. Heine ,&nbsp;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}

{"title":"Enhancing electrical discharge machining performance through nano H₂/O₂ bubble integration: A sustainable and optimized approach","authors":"Chia-Lung Kuo ,&nbsp;Chin-Ta Chen ,&nbsp;Chao-Ching Ho","doi":"10.1016/j.mne.2025.100306","DOIUrl":"10.1016/j.mne.2025.100306","url":null,"abstract":"<div><div>This study explores the integration of nano H₂/O₂ bubble liquid into Electrical Discharge Machining (EDM) and its impact on machining efficiency, precision, and sustainability. Experimental results demonstrate that the use of nano H₂/O₂ bubbles significantly enhances discharge dispersion, improves fluid flow for chip removal, and increases overall machining energy. For SUS316, machining time was reduced by up to 25 %, and for Ti6Al4V, by up to 31 %, when using a ϕ0.3 mm electrode. Additionally, electrode consumption decreased by up to 36 %, leading to improved cost-efficiency and reduced wear. The findings highlight the potential of nano H₂/O₂ bubble liquid in boosting EDM performance, offering a practical and environmentally sustainable solution for industrial applications by optimizing machining time, electrode consumption, and overall energy efficiency.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"28 ","pages":"Article 100306"},"PeriodicalIF":2.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144489361","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}

{"title":"Nanofabrication of superhydrophobic fluidic concentrators coupled with metallic plasmonic nano-antennas for SERS analysis in the sub-femtomolar range","authors":"Sofien Ramos ,&nbsp;Victor Fabre ,&nbsp;Mathieu Arribat ,&nbsp;Aurélie Lecestre ,&nbsp;Adrian Laborde ,&nbsp;Frank Carcenac ,&nbsp;Philippe Louarn ,&nbsp;Emmanuelle Trevisiol ,&nbsp;Christophe Vieu","doi":"10.1016/j.mne.2025.100314","DOIUrl":"10.1016/j.mne.2025.100314","url":null,"abstract":"<div><div>Self-assembled silicon nanopillars decorated with metallic nanoparticles have emerged as efficient Surface Enhanced Raman Spectroscopy (SERS) substrates. In this study, we combine black Silicon Reactive Ion Etching-Inductively Coupled Plasma (RIE-ICP) and thin film deposition of Silver (Ag) to produce this type of surface equipped with plasmonic nano-antennas. The paper describes a quantitative methodology for optimizing the fabrication process of such silicon SERS supports and specifically the determination of the nominal thickness of the Ag thin film, that upon fragmentation at the surface of the black‑silicon nanopillars, forms Ag nanoparticles capable of enhancing the local electromagnetic field. This parameter is crucial for tuning the surface density of generated hot spots on the surface and their electromagnetic enhancement factors. We propose a methodology based on the generation of hierarchical superhydrophobic fluidic concentrators and the development of a home-made algorithm for analyzing SERS spectra of Rhodamine B (RhB) solution at sub-femtomolar concentrations. The developed hierarchical clustering algorithm automatically selects from all the spectra acquired on the region of interest, the surface enhanced spectra containing at least three vibrational Raman signatures of RhB. The objective criterion for optimizing the fabrication process or for evaluating the performance of any SERS substrate is then simply the total number of RhB spectra finally retained by the algorithm. We detail the fabrication processes, the algorithmic method and through its experimental implementation we show how to tune the parameters of the algorithm for selecting the optimal Ag thin-film thickness.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"28 ","pages":"Article 100314"},"PeriodicalIF":3.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144879763","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}

{"title":"Nanofabrication of sharp conductive diamond tip probe chips and their application in reverse tip sample scanning probe microscopy","authors":"L. Wouters ,&nbsp;J. Cho ,&nbsp;S. Gim ,&nbsp;J. Yang ,&nbsp;A. Kanniainen ,&nbsp;K. Lee ,&nbsp;P. Lagrain ,&nbsp;N. Peric ,&nbsp;T. Hantschel","doi":"10.1016/j.mne.2025.100307","DOIUrl":"10.1016/j.mne.2025.100307","url":null,"abstract":"<div><div>Recently, a new scanning probe microscopy (SPM) concept called reverse tip sample scanning probe microscopy (RTS SPM) was introduced. Here, a sample is mounted at the end of a cantilever beam and scans over a tip that is integrated into an array of hundreds of SPM tips, overcoming one of the major limitations of the SPM technique, namely, the time-consuming and experiment-interrupting manual tip exchange step. However, to fully exploit this novel approach, a chip with an array of densely packed, nanometer-sharp, and durable SPM tips is essential. Therefore, we have developed a fabrication process to integrate such an array of sharp, high aspect ratio, doped diamond tips – referred to as hedgehog full diamond tip (HFDT) – into so-called probe chips, facilitating high-resolution SPM measurements and enabling rapid and seamless sample movement from one tip to another within the RTS SPM framework. An array of pyramidally shaped, doped diamond tips is fabricated through consecutive molding and diamond deposition steps. A supporting membrane is formed by metal deposition and electroplating, followed by selective underetching of the silicon substrate to release the tip array membrane and enable probe chip assembly. Finally, a self-patterned dry etching step is employed to generate multiple nanoscopic sharp tips on top of the base diamond pyramids. In this work, we present our developed and optimized probe chip technology and demonstrate its high electrical conductivity, robustness under high tip load force, and excellent spatial resolution, rendering it highly suitable for diverse electrical SPM measurement modes.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"28 ","pages":"Article 100307"},"PeriodicalIF":2.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144534496","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}

{"title":"Measurement of thickness of thin coatings on rough substrates via computational analysis of SEM images","authors":"A. Kondi ,&nbsp;E.-M. Papia ,&nbsp;V. Constantoudis ,&nbsp;D. Nioras ,&nbsp;I. Syngelakis ,&nbsp;C. Aivalioti ,&nbsp;E. Aperathitis ,&nbsp;E. Gogolides","doi":"10.1016/j.mne.2025.100315","DOIUrl":"10.1016/j.mne.2025.100315","url":null,"abstract":"<div><div>This work introduces a computational method to quantify the thickness of thin films deposited on highly rough substrates analyzing top-down Scanning Electron Microscope (SEM) images. The method entails measuring the bright areas of top-down SEM images of the rough surface obtained before and after deposition, allowing for the prediction of film thickness through the ratio of bright area enhancement caused by deposition to the average perimeter of these areas before and after deposition. Validation of this technique was conducted via synthetic SEM images with predefined film thicknesses, incorporating simple and complex substrate morphologies generated through Diffusion-Limited Aggregation (DLA) simulations for added realism. Experimental applications were explored through the analysis of SEM images of plasma-etched polymer (PMMA) surfaces coated with carbyne and of nanorods of TiO₂ coated with NiO, demonstrating the method's efficacy across varying surface roughness and morphologies. This work lays the foundation for future advancements, including the implementation of a neural network trained on synthetic datasets to enhance the measurement accuracy of coating thickness on rough substrates as well as the reconstruction of true surface morphologies prior to metal layer sputtering via SEM image analysis.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"28 ","pages":"Article 100315"},"PeriodicalIF":3.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144830655","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}

{"title":"Stability of masking materials for pattern transfer of lithographic masks into fused silica by atmospheric pressure plasma jet etching","authors":"Robert Heinke ,&nbsp;Lukáš Šilhan ,&nbsp;Martin Ehrhardt ,&nbsp;Pierre Lorenz ,&nbsp;Joachim Zajadacz ,&nbsp;Jens Bauer ,&nbsp;Thomas Arnold ,&nbsp;Mojmír Šerý ,&nbsp;Klaus Zimmer","doi":"10.1016/j.mne.2025.100309","DOIUrl":"10.1016/j.mne.2025.100309","url":null,"abstract":"<div><div>Masking of thin films and bulk materials is traditionally applied for the transfer of micron patterns into the functional material according to the requirements of the application. For optical purposes, lithographically produced micron patterns are transferred by plasma/ion etching, which is a traditional technology in microelectronics and other micron technologies. However, pattern transfer by atmospheric pressure plasma etching can help to save time and cost for a future sustainable production. Therefore, the pattern transfer of lithographic resist masks into fused silica using atmospheric pressure reactive plasma jets (APPJ) was studied as a new approach of micropatterning.</div><div>First the etch rates of the potential masking materials, e.g. photoresists, as well as of fused silica as substrate are studied in dependence on the APPJ etching parameters, in particular on the gas composition (O₂/CF₄) and the dwell time of the APPJ tool's footprint. Typical etch rates of the masking materials are in the range of 140 to 370 nm·s⁻¹ whereas the fused silica has a rate of 25 to 80 nm·s⁻¹. The surface morphology of masking materials changes during etching and features additional nanoscale roughness and waviness. The surface roughness of the etched masking materials and the fused silica are 2 to 5 nm rms and 1.5 nm rms for etch depths of ∼3000 nm and ∼ 600 nm, respectively. Finally, the pattern transfer by APPJ of a diffraction grating with a period of 15 μm, depth of 230 nm and a roughness below 2 nm rms into fused silica was demonstrated.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"28 ","pages":"Article 100309"},"PeriodicalIF":2.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144687296","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}

{"title":"Real time analysis of cancer ovarian cell growth and migration on soft surfaces","authors":"Maria Laura Coluccio ,&nbsp;Luigi Bruno ,&nbsp;Cristina Laurini ,&nbsp;Francesca Gualtieri ,&nbsp;Valentina Rocca ,&nbsp;Tahreem Arshad Butt ,&nbsp;Annamaria Cerantonio ,&nbsp;Anna Martina Battaglia ,&nbsp;Giuseppe Viglietto ,&nbsp;Carmela De Marco ,&nbsp;Francesco Gentile","doi":"10.1016/j.mne.2025.100303","DOIUrl":"10.1016/j.mne.2025.100303","url":null,"abstract":"<div><div>It is well established that the nano-geometry and mechanical properties of a material's interface can significantly influence - and potentially enhance - cell adhesion, growth, proliferation, and migration, collectively referred to as cell behavior. At the same time, these behavioral responses are inherently dependent on the cell's own biological characteristics, including its type, age, cell cycle phase, and whether it is normal or cancerous - as well as, in the latter case, the stage of cancer. In this context, we hypothesize that these material and cellular factors may act synergistically, such that carefully engineered materials can modulate and amplify cellular responses. Specifically, such materials may function as amplifiers, accentuating the behavioral differences between distinct cell lines and thereby improving our ability to distinguish between them. Here, we used this concept to segregate OVCAR-429 ovarian cancer cells silenced for the EXT1 gene (shEXT1) from a control (SCR): i.e. cells infected with an empty lentivirus. EXT1 encodes a glycosyltransferase implicated in the synthesis of heparan sulfate proteoglycans and may play a role in cancer cell invasion and metastasis. We produced polydimethylsiloxane (PDMS) substrates with low values of Young's modulus in the MPa range, and moderate values of roughness of about <span><math><mn>20</mn><mspace></mspace><mi>nm</mi></math></span>. Then, we monitored cell-behavior over time on PDMS substrates and on standard rigid microplates for comparison. Analysis of cell trajectories revealed that shEXT1 cells exhibited significantly reduced motility on PDMS surfaces compared control cells, with cell velocity and diffusivity reduced by more than twofold, whereas no significant differences were observed on standard surfaces. Our results thus indicate the potential of soft biomaterials to reveal biological differences in disease models.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"28 ","pages":"Article 100303"},"PeriodicalIF":2.8,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144312573","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}

{"title":"PowderMEMS® magnets as enabler for miniaturized NV based quantum sensors and quantum processor architectures","authors":"Mario Bähr ,&nbsp;Björn Gojdka ,&nbsp;Thomas Lisec ,&nbsp;Niels Clausen ,&nbsp;Mani Teja Bodduluri ,&nbsp;Aya Zino ,&nbsp;Indira Käpplinger ,&nbsp;Dominik Karolewski ,&nbsp;Jan Meijer ,&nbsp;Thomas Ortlepp","doi":"10.1016/j.mne.2025.100316","DOIUrl":"10.1016/j.mne.2025.100316","url":null,"abstract":"<div><div>The implementation of PowderMEMS® micromagnets of varying shapes, with lateral dimensions of 700 μm and 800 μm, into 2.3 × 2.3 × 0.525 mm³ silicon chips has been demonstrated successfully. These chips have been utilized as functionalized interposer for micro-scaled quantum devices. PowderMEMS® micromagnets offer a high biasing magnetic field flux density ranging from 30 mT to 35 mT over a distance of 100 μm depending on the size and shape of the micromagnets. This magnetic field strength (<em>B</em>_Z) was proven by room temperature ODMR measurements with NV centers in diamond: <em>B</em>_Z was measured over a range of distances, extending to 6 mm from the center of the micromagnets. The evaluation involved the analysis of Zeeman splitting. Furthermore, a Hall measurement setup was employed to map the lateral distribution of the magnetic field strength.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"28 ","pages":"Article 100316"},"PeriodicalIF":3.1,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144895448","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}