Pub Date : 2026-01-02DOI: 10.1016/j.mne.2025.100350
Raul Ruiz, Daniyal Khosh Maram, Xavier Cartoixà, Gabriel Abadal
This work presents the design and implementation of the MEMSTENNA relay, an innovative device that integrates a slot dipole antenna with a MEMS relay to enable wireless and batteryless switching control. The proposed concept exploits direct transduction from the electromagnetic to the mechanical domain, specifically within the gigahertz frequency range. The MEMSTENNA relay is fabricated on an FR4 PCB substrate incorporating a copper slot dipole antenna, designed to resonate at 1.2 GHz. Electromagnetic simulations reveal that, at a resonant frequency of 0.82 GHz, an incident electric field of 50 V/m is sufficient to exceed the pull-in voltage, thereby actuating the relay. Experimental validation demonstrates consistent operation with minimal excitation, highlighting the potential of this approach for energy-efficient integration of MEMS technology into RF systems.
{"title":"A MEMSTENNA relay: Coupling a slot dipole antenna with a MEMS relay for wireless and batteryless switching control","authors":"Raul Ruiz, Daniyal Khosh Maram, Xavier Cartoixà, Gabriel Abadal","doi":"10.1016/j.mne.2025.100350","DOIUrl":"10.1016/j.mne.2025.100350","url":null,"abstract":"<div><div>This work presents the design and implementation of the MEMSTENNA relay, an innovative device that integrates a slot dipole antenna with a MEMS relay to enable wireless and batteryless switching control. The proposed concept exploits direct transduction from the electromagnetic to the mechanical domain, specifically within the gigahertz frequency range. The MEMSTENNA relay is fabricated on an FR4 PCB substrate incorporating a copper slot dipole antenna, designed to resonate at <strong>1.2</strong> GHz. Electromagnetic simulations reveal that, at a resonant frequency of 0.82 GHz, an incident electric field of 50 V/m is sufficient to exceed the pull-in voltage, thereby actuating the relay. Experimental validation demonstrates consistent operation with minimal excitation, highlighting the potential of this approach for energy-efficient integration of MEMS technology into RF systems.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"30 ","pages":"Article 100350"},"PeriodicalIF":3.1,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939354","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}
Pub Date : 2026-01-02DOI: 10.1016/j.mne.2025.100344
Hilary Scott Nkimbeng Cho, Jin W. Choi
This paper presents a comprehensive comparative review of four widely used antenna-based sensor designs: slot, dipole, electromagnetic band gap (EBG), and patch antennas, highlighting their roles in various sensor applications. These antennas offer advantages, such as compact size, high sensitivity, ease of fabrication, and design flexibility, which make them be attractive for applications in environmental monitoring, health diagnostics, and structural sensing. The study investigates the operating principles, material configurations, and sensing mechanisms of each antenna type with an emphasis on how variations in the surrounding dielectric environment alter the effective permittivity and subsequently induce measurable shifts in the antenna's resonant frequency. Comparative analyses are conducted based on dielectric materials, operating frequency ranges, sensing targets, and resonance frequency shift, which serves as the primary sensing parameter. The findings highlight the adaptability and application-specific advantages of antenna-based sensors, that offer scalable solutions in a broad range of applications.
{"title":"Exploring the diversity of antenna-based sensors: A comparative study of slot, dipole, electromagnetic band gap, and patch designs","authors":"Hilary Scott Nkimbeng Cho, Jin W. Choi","doi":"10.1016/j.mne.2025.100344","DOIUrl":"10.1016/j.mne.2025.100344","url":null,"abstract":"<div><div>This paper presents a comprehensive comparative review of four widely used antenna-based sensor designs: slot, dipole, electromagnetic band gap (EBG), and patch antennas, highlighting their roles in various sensor applications. These antennas offer advantages, such as compact size, high sensitivity, ease of fabrication, and design flexibility, which make them be attractive for applications in environmental monitoring, health diagnostics, and structural sensing. The study investigates the operating principles, material configurations, and sensing mechanisms of each antenna type with an emphasis on how variations in the surrounding dielectric environment alter the effective permittivity and subsequently induce measurable shifts in the antenna's resonant frequency. Comparative analyses are conducted based on dielectric materials, operating frequency ranges, sensing targets, and resonance frequency shift, which serves as the primary sensing parameter. The findings highlight the adaptability and application-specific advantages of antenna-based sensors, that offer scalable solutions in a broad range of applications.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"30 ","pages":"Article 100344"},"PeriodicalIF":3.1,"publicationDate":"2026-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146037105","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}
Pub Date : 2025-12-26DOI: 10.1016/j.mne.2025.100349
Michael Georgas, Georgios Mitrousis, Filippos Farmakis
In this work we present a cost-effective, accessible method for fabricating high-resolution patterns such as interdigitated electrodes (IDEs) using a consumer-grade Liquid Crystal Display resin (LCD) printer as an alternative to traditional photolithography. By leveraging the native 17 μm pixel high resolution of the printer's monochrome LCD and its UV source, we achieved consistent electrode structures with feature sizes down to 17 μm, without necessitating photomasks or specialized equipment. As a proof-of-concept, IDEs patterned with this method were deposited with aluminum via Direct Current (DC) magnetron sputtering and used as the base for inkjet-printed PEDOT:PSS films, creating temperature sensors optimized for monitoring human body temperature. The sensors were tested over a narrow, physiologically relevant range (36–42 °C), and exhibited a strong, voltage-tunable temperature response. Across all tested bias levels, the devices showed a clear, linear decrease in resistance with increasing temperature, with absolute temperature coefficient of resistance (TCR) values reaching as high as . This performance exceeds values typically reported in literature for similar printed sensors. Overall, this approach offers a flexible, scalable, and affordable alternative to photolithography, with an emphasis on inkjet-printed temperature sensors suitable for wearable and biomedical applications.
{"title":"Accessible, high-resolution LCD lithography for microelectrode fabrication: Application to inkjet-printed PEDOT:PSS temperature sensors","authors":"Michael Georgas, Georgios Mitrousis, Filippos Farmakis","doi":"10.1016/j.mne.2025.100349","DOIUrl":"10.1016/j.mne.2025.100349","url":null,"abstract":"<div><div>In this work we present a cost-effective, accessible method for fabricating high-resolution patterns such as interdigitated electrodes (IDEs) using a consumer-grade Liquid Crystal Display resin (LCD) printer as an alternative to traditional photolithography. By leveraging the native 17 μm pixel high resolution of the printer's monochrome LCD and its UV source, we achieved consistent electrode structures with feature sizes down to 17 μm, without necessitating photomasks or specialized equipment. As a proof-of-concept, IDEs patterned with this method were deposited with aluminum via Direct Current (DC) magnetron sputtering and used as the base for inkjet-printed PEDOT:PSS films, creating temperature sensors optimized for monitoring human body temperature. The sensors were tested over a narrow, physiologically relevant range (36–42 °C), and exhibited a strong, voltage-tunable temperature response. Across all tested bias levels, the devices showed a clear, linear decrease in resistance with increasing temperature, with absolute temperature coefficient of resistance (TCR) values reaching as high as <span><math><mn>159.6</mn><mo>∗</mo><msup><mn>10</mn><mrow><mo>−</mo><mn>3</mn><mo>°</mo></mrow></msup><msup><mi>C</mi><mrow><mo>−</mo><mn>1</mn></mrow></msup></math></span>. This performance exceeds values typically reported in literature for similar printed sensors. Overall, this approach offers a flexible, scalable, and affordable alternative to photolithography, with an emphasis on inkjet-printed temperature sensors suitable for wearable and biomedical applications.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"30 ","pages":"Article 100349"},"PeriodicalIF":3.1,"publicationDate":"2025-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939351","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}
Pub Date : 2025-12-25DOI: 10.1016/j.mne.2025.100348
Cristina Laurini , Francesca Cutuli , Paola Cuzzola , Valentina Mollo , Edmondo Battista , Martina Paraggio , Luigi Bruno , Francesco Gentile , Maria Laura Coluccio
This study presents the development of a gold nanoparticle island substrate deposited on a polydimethylsiloxane (PDMS) disk. Metal nanoparticles are known for their strong electromagnetic response when illuminated by incident light. In Raman analysis, this phenomenon leads to a significant signal enhancement from molecules adsorbed on the nanoparticles, known as the Surface-Enhanced Raman Scattering (SERS) effect. In medical applications, this enables the detection of biomarkers in complex biological fluids, such as blood or saliva. In recent years, metallic nanoparticles assembled on silicon substrates have been successfully used for spectroscopic analysis, achieving high sensitivity in detecting trace biomolecules in biological mixtures. However, while these rigid devices offer excellent sensor performance, their lack of flexibility makes them unsuitable for direct application to biological samples, which are inherently soft. Here, we demonstrate a flexible PDMS-based plasmonic device. The fabrication process involves a two-step chemical deposition on a pre-patterned PDMS disk to create gold nanoparticle islands. Using a polymeric soft material instead of a semiconductor offers several advantages, including flexibility, transparency, good mechanical properties, and cost-effectiveness. Most importantly, a soft material can conform to biological tissues, enabling direct, on-site applications. The resulting soft device exhibits promising performance, not only for Raman analysis but also as a versatile platform for soft, metal-decorated materials with potential applications in biosensing and flexible electronics.
{"title":"Gold nanostructures: A way for their assembling on flexible devices","authors":"Cristina Laurini , Francesca Cutuli , Paola Cuzzola , Valentina Mollo , Edmondo Battista , Martina Paraggio , Luigi Bruno , Francesco Gentile , Maria Laura Coluccio","doi":"10.1016/j.mne.2025.100348","DOIUrl":"10.1016/j.mne.2025.100348","url":null,"abstract":"<div><div>This study presents the development of a gold nanoparticle island substrate deposited on a polydimethylsiloxane (PDMS) disk. Metal nanoparticles are known for their strong electromagnetic response when illuminated by incident light. In Raman analysis, this phenomenon leads to a significant signal enhancement from molecules adsorbed on the nanoparticles, known as the Surface-Enhanced Raman Scattering (SERS) effect. In medical applications, this enables the detection of biomarkers in complex biological fluids, such as blood or saliva. In recent years, metallic nanoparticles assembled on silicon substrates have been successfully used for spectroscopic analysis, achieving high sensitivity in detecting trace biomolecules in biological mixtures. However, while these rigid devices offer excellent sensor performance, their lack of flexibility makes them unsuitable for direct application to biological samples, which are inherently soft. Here, we demonstrate a flexible PDMS-based plasmonic device. The fabrication process involves a two-step chemical deposition on a pre-patterned PDMS disk to create gold nanoparticle islands. Using a polymeric soft material instead of a semiconductor offers several advantages, including flexibility, transparency, good mechanical properties, and cost-effectiveness. Most importantly, a soft material can conform to biological tissues, enabling direct, on-site applications. The resulting soft device exhibits promising performance, not only for Raman analysis but also as a versatile platform for soft, metal-decorated materials with potential applications in biosensing and flexible electronics.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"30 ","pages":"Article 100348"},"PeriodicalIF":3.1,"publicationDate":"2025-12-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939353","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}
Pub Date : 2025-12-20DOI: 10.1016/j.mne.2025.100347
Zhengyu Hu , Kewei Cao , Tengfei Yan
Chemically amplified photoresists have been used in semiconductor lithography for more than four decades. These materials consist of an acid-sensitive polymer matrix and a small amount of photoacid generator, which decomposes upon exposure to radiation to produce strong acid, and other additives. During the subsequent post-exposure bake, the generated acid catalyzes the deprotection reaction of the polymer, resulting in a change in solubility that enables pattern formation. This patterning process is governed by a coupled reaction–diffusion mechanism, where the diffusion length of the acid catalyst directly affects the final feature dimensions. Photoacid diffusion affects the key performance parameters including sensitivity and resolution of chemically amplified photoresists. Accordingly, understanding and accurately characterizing the diffusion process is essential for analyzing and optimizing the performance of the photoresist. This review covers the acid diffusion mechanism in polymers and the application of various experimental techniques for probing photoacid diffusion in chemically amplified photoresists. It also discusses promising approaches for the control and detection of photoacid diffusion.
{"title":"Photoacid diffusion in chemically amplified photoresists and its detection methods: A review","authors":"Zhengyu Hu , Kewei Cao , Tengfei Yan","doi":"10.1016/j.mne.2025.100347","DOIUrl":"10.1016/j.mne.2025.100347","url":null,"abstract":"<div><div>Chemically amplified photoresists have been used in semiconductor lithography for more than four decades. These materials consist of an acid-sensitive polymer matrix and a small amount of photoacid generator, which decomposes upon exposure to radiation to produce strong acid, and other additives. During the subsequent post-exposure bake, the generated acid catalyzes the deprotection reaction of the polymer, resulting in a change in solubility that enables pattern formation. This patterning process is governed by a coupled reaction–diffusion mechanism, where the diffusion length of the acid catalyst directly affects the final feature dimensions. Photoacid diffusion affects the key performance parameters including sensitivity and resolution of chemically amplified photoresists. Accordingly, understanding and accurately characterizing the diffusion process is essential for analyzing and optimizing the performance of the photoresist. This review covers the acid diffusion mechanism in polymers and the application of various experimental techniques for probing photoacid diffusion in chemically amplified photoresists. It also discusses promising approaches for the control and detection of photoacid diffusion.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"30 ","pages":"Article 100347"},"PeriodicalIF":3.1,"publicationDate":"2025-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146037104","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}
Pub Date : 2025-12-19DOI: 10.1016/j.mne.2025.100345
Shareena Muringakodan , Sina Zare Pakzad , Ulrich Schmid , Michael Schneider
In this paper, we demonstrate the fabrication and characterization of bistable piezoelectric plates with a precisely tuned residual stress to achieve buckling-induced bistability. The plate consist of a multilayered structure, with a piezoelectric aluminum nitride layer sandwiched between top and bottom electrode layers. The stress in the aluminum nitride thin film is tuned by adjusting the DC magnetron sputtering parameters, including sputtering pressure, gas flow rates, target-substrate distance, and substrate bias voltage to introduce the compressive stress needed to induce plate buckling. Experimental results demonstrate that reducing sputtering pressure while controlling nitrogen flow, with no argon admixture, and applying a substrate bias voltage above 10 V enables compressive stress in the aluminum nitride layer within the desired range of −800 to −600 MPa, resulting in bistable plates. The bistability of the fabricated plates is evaluated by analyzing their potential energy profiles under applied external perpendicular forces, using a bulge test setup, where uniform air pressure is applied to the plate surface. The plates exhibit a characteristic hysteresis loop in their load-deflection response, with transitions between buckled-down and buckled-up states at approximately 10 mbar and −30 mbar, respectively. The initial buckling amplitude of the fabricated plates, within the optimized stress range, is measured to be 5–7 m, with a total displacement of 10–12 m when switching between both states. Furthermore, in each stable state, the plates exhibit an additional displacement of approximately 5 m when subjected to a relative air pressure of 1 bar.
{"title":"Stress optimization in DC magnetron sputtered AlN layers for fully clamped bistable piezoelectric plate devices","authors":"Shareena Muringakodan , Sina Zare Pakzad , Ulrich Schmid , Michael Schneider","doi":"10.1016/j.mne.2025.100345","DOIUrl":"10.1016/j.mne.2025.100345","url":null,"abstract":"<div><div>In this paper, we demonstrate the fabrication and characterization of bistable piezoelectric plates with a precisely tuned residual stress to achieve buckling-induced bistability. The plate consist of a multilayered structure, with a piezoelectric aluminum nitride layer sandwiched between top and bottom electrode layers. The stress in the aluminum nitride thin film is tuned by adjusting the DC magnetron sputtering parameters, including sputtering pressure, gas flow rates, target-substrate distance, and substrate bias voltage to introduce the compressive stress needed to induce plate buckling. Experimental results demonstrate that reducing sputtering pressure while controlling nitrogen flow, with no argon admixture, and applying a substrate bias voltage above 10 V enables compressive stress in the aluminum nitride layer within the desired range of −800 to −600 MPa, resulting in bistable plates. The bistability of the fabricated plates is evaluated by analyzing their potential energy profiles under applied external perpendicular forces, using a bulge test setup, where uniform air pressure is applied to the plate surface. The plates exhibit a characteristic hysteresis loop in their load-deflection response, with transitions between buckled-down and buckled-up states at approximately 10 mbar and −30 mbar, respectively. The initial buckling amplitude of the fabricated plates, within the optimized stress range, is measured to be 5–7 <span><math><mi>μ</mi></math></span>m, with a total displacement of 10–12 <span><math><mi>μ</mi></math></span>m when switching between both states. Furthermore, in each stable state, the plates exhibit an additional displacement of approximately 5 <span><math><mi>μ</mi></math></span>m when subjected to a relative air pressure of <span><math><mo>∼</mo></math></span> 1 bar.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"30 ","pages":"Article 100345"},"PeriodicalIF":3.1,"publicationDate":"2025-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145939257","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}
Pub Date : 2025-12-15DOI: 10.1016/j.mne.2025.100346
Hong-Hui Lian, Kai-Jung Chen, Ming-Yi Tsai
Silicon carbide (SiC) is not only notoriously difficult to finish by chemical mechanical polishing (CMP) owing to its ultrahigh hardness and chemical inertness, but it has also become the material of choice for a new generation of harsh-environment sensors—including deep-UV photodiodes, piezoresistive pressure chips for turbine combustors, and micro-resonant chemical detectors—whose responsivity, quality factor, and long-term drift are exceedingly sensitive to sub-surface damage and nanoscale surface roughness. Consequently, elevating SiC-CMP surface quality and throughput is pivotal for manufacturing low-noise, reliable sensor dies at competitive cost. This research, therefore, explores the integration of a mixed-abrasive slurry (MAS) endowed with photocatalytic activity into the SiC-CMP process to realize a high-efficiency, cost-effective, and environmentally friendlier finishing route. The study details MAS preparation via high-energy ball milling and evaluates the polishing effectiveness of two distinct formulations. Using an MAS composed of SiO₂ and TiO₂/rGO abrasives, we achieve a material-removal rate of 823 nm/h and a surface roughness of 0.350 nm under UV irradiation, demonstrating the slurry's suitability for fabricating sensor-grade SiC surfaces.
{"title":"Developing photo-catalytic mechanical polishing fluid for the chemical-mechanical polishing process of single-crystal silicon carbide","authors":"Hong-Hui Lian, Kai-Jung Chen, Ming-Yi Tsai","doi":"10.1016/j.mne.2025.100346","DOIUrl":"10.1016/j.mne.2025.100346","url":null,"abstract":"<div><div>Silicon carbide (SiC) is not only notoriously difficult to finish by chemical mechanical polishing (CMP) owing to its ultrahigh hardness and chemical inertness, but it has also become the material of choice for a new generation of harsh-environment sensors—including deep-UV photodiodes, piezoresistive pressure chips for turbine combustors, and micro-resonant chemical detectors—whose responsivity, quality factor, and long-term drift are exceedingly sensitive to sub-surface damage and nanoscale surface roughness. Consequently, elevating SiC-CMP surface quality and throughput is pivotal for manufacturing low-noise, reliable sensor dies at competitive cost. This research, therefore, explores the integration of a mixed-abrasive slurry (MAS) endowed with photocatalytic activity into the SiC-CMP process to realize a high-efficiency, cost-effective, and environmentally friendlier finishing route. The study details MAS preparation via high-energy ball milling and evaluates the polishing effectiveness of two distinct formulations. Using an MAS composed of SiO₂ and TiO₂/rGO abrasives, we achieve a material-removal rate of 823 nm/h and a surface roughness of 0.350 nm under UV irradiation, demonstrating the slurry's suitability for fabricating sensor-grade SiC surfaces.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"30 ","pages":"Article 100346"},"PeriodicalIF":3.1,"publicationDate":"2025-12-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798573","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}
Pub Date : 2025-12-11DOI: 10.1016/j.mne.2025.100342
George Mitrousis, Michael Georgas, Loukas Michalas, Filippos Farmakis
In this work, we present a low-temperature and cost-effective fabrication of zinc oxide (ZnO) based thin film transistors (TFTs) having high-k zirconium oxide (ZrO2) thin films as gate dielectrics. By employing a sol-gel approach combined with urea-assisted solution combustion synthesis (SCS), we reduced the thermal annealing budget to 200 °C, enabling the deposition of uniform and transparent (>98 % optical transparency in the visible range) dielectric films suitable for temperature sensitive substrates. The resulting ZrO2 layers exhibit a relative permittivity (k) of approximately 12.9 at 4 kHz and a leakage current density of 10−7 A cm−2 for electric field equal to 105 V cm−1 supporting low-voltage TFT operation. TFTs with ZnO active channels and indium tin oxide (ITO) source and drain electrodes were fabricated and patterned using liquid crystal display (LCD) based photolithography without necessitating photomasks or specialized patterning equipment for additive printing. The devices showed well-defined transistor characteristics with field-effect mobilities reaching 0.42 cm2 V−1 s−1, threshold voltages around −0.33 V, subthreshold swing of 491 mV dec−1 and on/off current ratios on the order of 102. Overall, this approach offers a flexible, scalable and low-temperature route to fabricating high-k ZrO2 gate dielectrics, while the addition of an affordable alternative to photolithography facilitates rapid prototyping of TFT devices.
在这项工作中，我们提出了一种以高k氧化锆（ZrO2）薄膜作为栅极电介质的低温和经济高效的氧化锌（ZnO）薄膜晶体管（TFTs）的制造方法。通过采用溶胶-凝胶方法结合尿素辅助溶液燃烧合成（SCS），我们将热退火预算降低到200°C，从而能够沉积均匀透明（可见光范围内光学透明度为98%）的介电薄膜，适用于温度敏感基底。所得的ZrO2层在4 kHz时的相对介电常数(k)约为12.9，当电场为105 V cm−1时，漏电流密度为10−7 a cm−2，支持低压TFT操作。采用基于液晶显示（LCD）的光刻技术制备了具有ZnO有源通道和氧化铟锡（ITO）源极和漏极的TFTs，并对其进行了图案化处理，而不需要光掩膜或专门的图案化设备进行增材印刷。器件表现出良好的晶体管特性，场效应迁移率达到0.42 cm2 V - 1 s - 1，阈值电压约为- 0.33 V，亚阈值摆幅为491 mV dec - 1，开/关电流比约为102。总的来说，这种方法为制造高k ZrO2栅极电介质提供了一种灵活、可扩展和低温的途径，同时增加了一种经济实惠的光刻替代方案，促进了TFT器件的快速原型制作。
{"title":"Low-thermal-budget fabrication of ZnO TFTs via urea-assisted combustion synthesis of high-k ZrO2 gate dielectrics","authors":"George Mitrousis, Michael Georgas, Loukas Michalas, Filippos Farmakis","doi":"10.1016/j.mne.2025.100342","DOIUrl":"10.1016/j.mne.2025.100342","url":null,"abstract":"<div><div>In this work, we present a low-temperature and cost-effective fabrication of zinc oxide (ZnO) based thin film transistors (TFTs) having high-k zirconium oxide (ZrO<sub>2</sub>) thin films as gate dielectrics. By employing a sol-gel approach combined with urea-assisted solution combustion synthesis (SCS), we reduced the thermal annealing budget to 200 °C, enabling the deposition of uniform and transparent (>98 % optical transparency in the visible range) dielectric films suitable for temperature sensitive substrates. The resulting ZrO<sub>2</sub> layers exhibit a relative permittivity (<em>k</em>) of approximately 12.9 at 4 kHz and a leakage current density of 10<sup>−7</sup> A cm<sup>−2</sup> for electric field equal to 10<sup>5</sup> V cm<sup>−1</sup> supporting low-voltage TFT operation. TFTs with ZnO active channels and indium tin oxide (ITO) source and drain electrodes were fabricated and patterned using liquid crystal display (LCD) based photolithography without necessitating photomasks or specialized patterning equipment for additive printing. The devices showed well-defined transistor characteristics with field-effect mobilities reaching 0.42 cm<sup>2</sup> V<sup>−1</sup> s<sup>−1</sup>, threshold voltages around −0.33 V, subthreshold swing of 491 mV dec<sup>−1</sup> and on/off current ratios on the order of 10<sup>2</sup>. Overall, this approach offers a flexible, scalable and low-temperature route to fabricating high-k ZrO<sub>2</sub> gate dielectrics, while the addition of an affordable alternative to photolithography facilitates rapid prototyping of TFT devices.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"30 ","pages":"Article 100342"},"PeriodicalIF":3.1,"publicationDate":"2025-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145798574","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}
Pub Date : 2025-12-08DOI: 10.1016/j.mne.2025.100343
Javier Bravo , Lisandro Jofre , Paloma Tejedor
Hybrid InAs–Al nanowires are essential building blocks for topological qubits, owing to their ability to host Majorana zero modes. In this work, we present a scalable method for fabricating ordered arrays of Au nanodots on GaAs(111)B substrates using laser interference lithography (LIL) in combination with a multilayer hard-mask process. These nanodot arrays enable site-controlled growth of InAs and InAs–Al nanowires via molecular beam epitaxy (MBE) using the vapor–liquid–solid (VLS) mechanism. Surface cleaning treatments are found to strongly influence nanowire morphology and growth yield, with HCl-based cleaning providing enhanced selectivity for vertical (111)B-oriented nanowire growth. Structural characterization by scanning electron microscopy (SEM) and reflection high-energy electron diffraction (RHEED) confirms the formation of uniform wurtzite-phase InAs nanowires subsequently coated with conformal Al shells. Although further yield optimization is required, the results demonstrate that LIL enables large-area, deterministic nanowire positioning with the structural quality necessary for quantum device fabrication, representing a significant advance toward scalable topological quantum computing.
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Pub Date : 2025-12-01DOI: 10.1016/j.mne.2025.100339
Serena Basile , Johannes F.L. Goosen
As engineering applications become increasingly complex, the need for miniaturization is present in several technological fields. Places hardly reachable by traditional tools and machines, can be accessed thanks to miniaturized devices and, especially when such devices are remotely controlled or autonomous, it implies the need for miniaturized, standalone actuators. Most high-energy density actuators for these applications can not be operated if untethered from an external power-supply.
In this study, we investigate the manufacturing of a mesoscale compliant expansion chamber for a miniaturized chemical-based actuator. Photopolymerization and material jetting are used for manufacturing the prototypes, exhibiting dimensions of 9.8 mm diameter, 7.5 mm height and 140 μm thickness. These dimensions are such as to allow the device to fit inside of the flapping wings micro aerial vehicle (FWMAV) that it has to power. Fabrication of such dimensions, along with the peculiar geometry of the chamber, taps into the limitations of the photopolymerization process and highlights areas of improvement for this rapidly-developing technology. The devices are successfully tested for a linear motion, mimicking that of a cylinder-piston combination, as in a conventional expansion chamber, and are actuated by a pressure pulse.
{"title":"A mesoscale compliant expansion chamber for a catalytic micro-engine","authors":"Serena Basile , Johannes F.L. Goosen","doi":"10.1016/j.mne.2025.100339","DOIUrl":"10.1016/j.mne.2025.100339","url":null,"abstract":"<div><div>As engineering applications become increasingly complex, the need for miniaturization is present in several technological fields. Places hardly reachable by traditional tools and machines, can be accessed thanks to miniaturized devices and, especially when such devices are remotely controlled or autonomous, it implies the need for miniaturized, standalone actuators. Most high-energy density actuators for these applications can not be operated if untethered from an external power-supply.</div><div>In this study, we investigate the manufacturing of a mesoscale compliant expansion chamber for a miniaturized chemical-based actuator. Photopolymerization and material jetting are used for manufacturing the prototypes, exhibiting dimensions of 9.8 mm diameter, 7.5 mm height and 140 μm thickness. These dimensions are such as to allow the device to fit inside of the flapping wings micro aerial vehicle (FWMAV) that it has to power. Fabrication of such dimensions, along with the peculiar geometry of the chamber, taps into the limitations of the photopolymerization process and highlights areas of improvement for this rapidly-developing technology. The devices are successfully tested for a linear motion, mimicking that of a cylinder-piston combination, as in a conventional expansion chamber, and are actuated by a pressure pulse.</div></div>","PeriodicalId":37111,"journal":{"name":"Micro and Nano Engineering","volume":"29 ","pages":"Article 100339"},"PeriodicalIF":3.1,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145623728","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}
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