Zhi-Xuan Dai, Chun-Yu Chen, Bo-Chun Chiu, Chi-Yuan Lee
{"title":"Manufacturing and measurement of CMOS-MEMS-based micro thermoelectric generators with long-length thermocouples","authors":"Zhi-Xuan Dai, Chun-Yu Chen, Bo-Chun Chiu, Chi-Yuan Lee","doi":"10.1088/1361-6439/ad520b","DOIUrl":"https://doi.org/10.1088/1361-6439/ad520b","url":null,"abstract":"The study explores the fabrication and evaluation of a micro thermoelectric generator (MTG) with long-length thermocouples (TCs) through the utilization of a commercial complementary metal oxide semiconductor process. The MTG consists of 23 TCs, and its performance is intricately linked to the temperature difference (<italic toggle=\"yes\">T</italic>\u0000<sub>diff</sub>) between the cold and hot sides of these TCs. An increase in <italic toggle=\"yes\">T</italic>\u0000<sub>diff</sub> leads to higher output voltage and power for the MTG. To enhance <italic toggle=\"yes\">T</italic>\u0000<sub>diff</sub>, the TCs are designed to be 700 <italic toggle=\"yes\">µ</italic>m in length, and an innovative design has been implemented on the cold side of the TCs, creating a suspended structure to improve heat dissipation A post-process is essential for achieving this suspended TC structure. The results demonstrate that the TC structure is fully suspended and remains undamaged. The measured outcomes reveal an output voltage of 13.8 mV when the <italic toggle=\"yes\">T</italic>\u0000<sub>diff</sub> reaches 3.5 K. Under these conditions, the MTG exhibits a voltage factor of 2.76 mV mm<sup>−2</sup>K<sup>−1</sup>. Furthermore, at a <italic toggle=\"yes\">T</italic>\u0000<sub>diff</sub> of 3.5 K, the maximum output power reaches 2.1 nW. The MTG demonstrates a power factor of 0.12 nW mm<sup>−2</sup> K<sup>−2</sup>.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"9 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-06-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141551345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Development of a novel monolithic compliant Lorentz-force-driven XY nanopositioning system","authors":"Xu Yang, Xin Liu, Yilong Zhu, Feng Qiao, Shizhen Li, Zhiwei Zhu, Limin Zhu","doi":"10.1088/1361-6439/ad2f47","DOIUrl":"https://doi.org/10.1088/1361-6439/ad2f47","url":null,"abstract":"A novel monolithic compliant Lorentz-force-driven XY nanopositioning system (MCLNS) is designed, analyzed, and experimentally assessed with the aim of high-resolution positioning across a large workspace. A double-symmetric Lorentz-force actuator (DSLA) with the benefits of zero friction, high thrust, and large stroke is proposed to generate the actuation force. Correspondingly, a monolithic four-prismatic parallel compliant mechanism (4P-PCM) is exploited to transmit the actuation motion to the central platform and minimize the parasitic motion. The unique integration of four DSLAs and one 4P-PCM make the proposed MCLNS possess compact structure and stable performance. The characterization of the MCLNS is formulated by a specially established analytical model and validated by finite-element analysis simulation and experimental tests. Experimental studies show that the workspace of the MCLNS prototype is large than 0.87 × 0.87 mm<sup>2</sup> and the positioning resolution of the MCLNS prototype is better than 9 nm. By means of a nonlinear forward proportional integral derivative control strategy, the maximum contouring error of the MCLNS is maintained within 2.7% while tracking a 1257 <italic toggle=\"yes\">μ</italic>m s<sup>−1</sup> circular trajectory.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"53 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140593089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Corrigendum: Dynamic micromechanical measurement of the flexural modulus of micrometre-sized diameter single natural fibres using a vibrating microcantilever technique (2024 J. Micromech. Microeng. 34 015009)","authors":"Ali Reda, Thomas Dargent, Steve Arscott","doi":"10.1088/1361-6439/ad3659","DOIUrl":"https://doi.org/10.1088/1361-6439/ad3659","url":null,"abstract":"This corrigendum corrects typographic errors in the article. The corrections do not change the conclusions of the article.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"206 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140592713","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Marcin Michałowski, Zbigniew Kusznierewicz, Sergiusz Łuczak, Artur Chańko, Mateusz Samsel, Paweł Pieńczuk
{"title":"Sub-miniature rolling thrust micro-bearing","authors":"Marcin Michałowski, Zbigniew Kusznierewicz, Sergiusz Łuczak, Artur Chańko, Mateusz Samsel, Paweł Pieńczuk","doi":"10.1088/1361-6439/ad31b9","DOIUrl":"https://doi.org/10.1088/1361-6439/ad31b9","url":null,"abstract":"The original design of the smallest two-way rolling thrust micro-bearing with sub-millimeter dimensions is presented. The bearing is self-contained and is capable of transmitting thrust load up to about 8 N in two directions, as well as radial loads up to about 0.4 N. Thanks to special design of the raceways, operation without lubrication is possible. The scope of experimental study is discussed, and preliminary experimental results are reported. Ways of further miniaturization are suggested.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"192 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140314026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Wafer-scale silicon microfabrication technology toward realization of low-cost sub-THz waveguide devices","authors":"Xinghai Zhao, Peng Wu, Fei Liu","doi":"10.1088/1361-6439/ad2aee","DOIUrl":"https://doi.org/10.1088/1361-6439/ad2aee","url":null,"abstract":"This paper presents a wafer-scale silicon microfabrication technology for the sub-terahertz (sub-THz) waveguide device mass production. Based on the effective scheme, a WR-5 (140–220 GHz) straight rectangular waveguide and a WR-2.8 (260–400 GHz) rectangular waveguide bandpass filter are implemented as demonstrated examples. The silicon deep reactive ion etching (DRIE) process is employed to etch through the total thickness of the silicon wafer and form the main waveguide channels. Then, a low-temperature thermal compression process is used to bond the trough-etched wafer with the top and bottom metallised silicon wafers to form the closed waveguide structures without any precise alignment process. The fabricated waveguide has the benefit of low transmission loss (0.03–0.05 dB mm<sup>−1</sup>) at the whole G band. Besides, to measure the fabricated WR-2.8 waveguide filter and solve the measuring equipment standard waveguide difference, silicon micromachined waveguide transitions are explored and fabricated to match two different frequency-band modules for measuring the waveguide filters in the desired full frequency band, which also has a potential application for the different size waveguide conversion. The measured results agree well with the simulated ones. The measured 3 dB bandwidth is 9.3%, with a central frequency of 343 GHz; the average insertion loss (IL) is about 1.6 dB in the pass band, including two extra straight waveguides of 8 mm length on input/output ends and two external waveguide-to-waveguide transitions. The proposed method provides a feasible and cost-effective solution for the mass production of high-performance waveguide devices and integrated systems in sub-THz frequency bands and beyond.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"158 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140314013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Negin Sherkat, Athira Kattiparambil Sivaprasad, Uwe Pelz, Peter Woias
{"title":"Innovating in-situ characterization: a comprehensive measurement system for measuring the ZT and the contact resistance of vertical thermolegs exploiting the vertical transfer length method","authors":"Negin Sherkat, Athira Kattiparambil Sivaprasad, Uwe Pelz, Peter Woias","doi":"10.1088/1361-6439/ad2d65","DOIUrl":"https://doi.org/10.1088/1361-6439/ad2d65","url":null,"abstract":"In order to optimize their system design and manufacturing processes, it is crucial to undertake a thorough electrical and thermal characterization of micro thermoelectric generators (<italic toggle=\"yes\">µ</italic>TEGs). To address this need, a highly advanced and fully integrated <italic toggle=\"yes\">in-situ</italic> measurement system has been developed. The main objectives of this system are to (1) enable the measurement of ZT and thereby of all thermoelectric (TE) properties of thermolegs made from powder-based TE materials and (2) at the same time accurately measure the contact resistance between the TE material and the electrical contacts. The <italic toggle=\"yes\">µ</italic>TEG fabrication concept used in this study is based on copper-cladded printed circuit board (PCB) material as a substrate, using the Cu layers for easy contact formation. In a first step, an innovative measurement concept, based on a distinctive vertical rendition of the well-established transfer length method, has been realized, allowing for the <italic toggle=\"yes\">in-situ</italic> measurement of contact resistance between the TE material and the copper conductors on the PCB substrate. This enables a comprehensive assessment of the impact exerted by the applied force and temperature during e.g. a hot-pressing step for compacting the powder-based thermolegs during the manufacturing process. In a second step, a comprehensive measurement platform, referred to as the ZT-Card, has been devised to facilitate the evaluation of all relevant TE material properties—Seebeck voltage, electrical conductivity and thermal conductivity (all measured in vertical cross-plane orientation)—inherent to a highly miniaturized thermoleg. Additionally, the ZT-Card also allows for the assessment of contact resistance between the copper contacts and the TE material. Successful testing of this measurement system inspires confidence in the capabilities of the platform and will aid in future <italic toggle=\"yes\">µ</italic>TEG development.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"8 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140313926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Design and fabrication of a sensors-integrated silicon electrode for gap status monitoring in micro electrochemical machining","authors":"Yulan Zhu, Guodong Liu, Yong Li, Hao Tong","doi":"10.1088/1361-6439/ad2c1f","DOIUrl":"https://doi.org/10.1088/1361-6439/ad2c1f","url":null,"abstract":"The monitoring of micro machining gap and the control of machining status within the gap have become bottlenecks in the research and development of micro electrochemical machining (ECM). General electrical signals are difficult to reflect the status of micro machining gap. Electrolytic products in micro machining gap are prone to precipitation and retention, leading to unstable material removal process. Micro ECM urgently requires gap status monitoring and feedback control. To realize gap status monitoring, a sensors-integrated silicon electrode, with a micro temperature sensor and a micro conductivity sensor on the silicon electrode near-front sidewall, is proposed innovatively in this study. Based on bulk silicon process and electroplating process, sensors-integrated silicon electrodes are designed and fabricated. Based on the signal processing system built for the temperature and conductivity sensor, the temperature and conductivity detection functions are verified and the sensors are calibrated. Micro ECM experiments with sensors-integrated silicon electrodes are carried out and micro holes with 200 <italic toggle=\"yes\">μ</italic>m depth are machined. For the conductivity sensor on the sensors-integrated silicon electrode, due to the affection of electrolytic environment, the function surface is contaminated and damaged, and the structural design needs to be further improved. For the temperature sensor, it is not affected by the electrolytic environment due to insulation-film’s protection, and reliable temperature monitoring is achieved in micro ECM. The detection results indicate that the temperature inside the machining gap has increased by 20 °C due to the electrochemical thermal effect and resistance thermal effect in micro ECM, and the temperature shows an increasing trend while machining depth increasing. The feasibility of process monitoring with sensors-integrated silicon electrode in micro ECM is preliminarily verified.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"87 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140314015","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Computational modelling and experimental investigation of micro-electrochemical discharge machining by controlling the electrolyte temperature","authors":"Dil Bahar, Akshay Dvivedi, Pradeep Kumar","doi":"10.1088/1361-6439/ad2089","DOIUrl":"https://doi.org/10.1088/1361-6439/ad2089","url":null,"abstract":"Glass vias are emerging as a favourable option for radiofrequency-based micro-electromechanical system packaging. For the micromachining of glass, electrochemical discharge machining (ECDM) could be the most suitable technique if issues pertaining to the process stability are addressed thoroughly. The electrolyte temperature has immense influence on the viscosity and conductivity of the electrolyte, which percolate the stability of the ECDM process. Therefore, this article investigates the effects of the electrolyte temperature and applied voltage on the performance characteristics of ECDM for the micromachining of borosilicate glass. The machining rate (MR) and hole overcut (HOC) of the machined microholes are considered as performance characteristics. A 3D thermal-based finite element model (FEM) was developed for the thermal analysis in the machining zone. In the thermal analysis, the heat flux by thermal discharge was assumed to have Gaussian distribution, and accordingly, temperature profiles in the thermal zone were analyzed by controlling the electrolyte temperature and voltage at various levels. Further processing of temperature profiles in the thermal zone was utilized in the estimation of MR and HOC. Electrostatic-based FEM was utilized to assess the intensity of the electric field in the proximity of the tool electrode to analyze the probable locations of thermal discharge and its impact on the geometrical characteristics of the machined microholes. The simulation outcomes were validated experimentally, and show good agreement. A field emission electron microscope with energy dispersive spectroscopy was used for the characterization of the machined surface to observe the effect of the electrolyte temperature.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"1 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139765751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Highly sensitive flexible capacitive pressure sensor with structured elastomeric dielectric layers","authors":"Gaurav Rawal, Animangsu Ghatak","doi":"10.1088/1361-6439/ad1e35","DOIUrl":"https://doi.org/10.1088/1361-6439/ad1e35","url":null,"abstract":"Sensitive yet stable, robust yet flexible and accurate yet energy efficient pressure sensors are required for variety of purposes. While a large variety of designs and dielectric materials have been explored for this purpose, there is still need of a flexible pressure sensor that will allow easy scale up and inexpensive fabrication. To this end, we have presented here the design of a flexible capacitive pressure sensor using copper coated paper as flexible electrodes and soft Ecoflex layers decorated with cylindrical micro-pillars as the dielectric. While microscopic construct of the sensor allows its easy manufacturability, softness of the layer imparts sensitivity to it. In contrast to many conventional sensors, this design yields sensitivity as high as ∼5 kPa<sup>−1</sup> at pressure <1 kPa and somewhat smaller sensitivity as pressure exceeds 1 kPa. We have varied systematically pillar diameter, skin thickness of dielectric layer and pitch of the pillar array to optimise the design and demonstrate its easy tunability. We have presented a model based on buckling of the pillars to predict the response of the sensor. We have explored also a specific design that minimises the hysteresis.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"64 1","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139765763","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bo Zhou, Longfei Xie, Tingli Wang, Bo Su, Junhu Meng
{"title":"Fabrication of high-aspect-ratio metallic microstructures by microelectroforming using silver-coated polydimethylsiloxane molds with controllable wettability","authors":"Bo Zhou, Longfei Xie, Tingli Wang, Bo Su, Junhu Meng","doi":"10.1088/1361-6439/ad1c72","DOIUrl":"https://doi.org/10.1088/1361-6439/ad1c72","url":null,"abstract":"\u0000 Microelectroforming is a specialized electroplating process to prepare functional metallic microstructures. However, the formability of microelectroforming is usually restricted by the limited mass transfer in high-aspect-ratio microcavities of molds. This paper presents a simple and reliable method utilizing silver (Ag)-coated polydimethylsiloxane (PDMS) molds with controllable wettability to enhance the formability of microelectroforming. The surfaces of these molds exhibited reversible water contact angles ranging from 4° to 151° realized through ultraviolet irradiation and heat treatment. The hydrophilicity of the PDMS molds facilitated liquid-phase mass transfer, contributing to the fabrication of complete and defect-free nickel microstructures with high aspect ratios. Subsequently, the hydrophobic PDMS molds reduced the interfacial adhesion between these molds and nickel microstructures, which was beneficial for perfect demolding. Nickel microstructures with an aspect ratio of 10 can be achieved by using the PDMS molds, which significantly enhance the formability of microelectroforming. This method provides a potential method to prepare high-aspect-ratio metallic microstructures.","PeriodicalId":16346,"journal":{"name":"Journal of Micromechanics and Microengineering","volume":"32 22","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139442775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}