Selected Papers from ICMA2021

A special issue of Micromachines (ISSN 2072-666X).

Deadline for manuscript submissions: closed (15 July 2021) | Viewed by 24014

Special Issue Editor


E-Mail Website
Guest Editor
Department of Mechanical and Industrial Engineering, Concordia University, 1455 de Maisonneuve Blvd. West, Montreal, QC H3G 1M8, Canada
Interests: microsystems; sensing (inertial, flow, load, strain); design of MEMS; data processing; modeling of coupled micro and macro systems; packaging of microsensors; MEMS for turbulence control; microfabrication; non-conventional microfabrication; rapid prototyping; migration from auto to aero; reliability of MEMS; failure models; test methodologies
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

This Special Issue is cooperating with 1st International Conference on Micromachines and Applications (ICMA2021, https://sciforum.net/conference/Micromachines2021), which will be held online from 15-30 April 2021). The registration is free of charge—both for authors and attendees.

The conference will be organized into 9 sessions, which reflect the interdisciplinary nature of micromachines and its applications:

Session 1: Micromachines for scientific research
Session 2: Microfluidic micromachines
Session 3: Micromachines for bio-medical applications
Session 4: Micromachines for bio-chemical applications
Session 5: Micromachines for green energy
Session 6: Micromachines for a clean environment
Session 7: Micromachines for bio-sensing
Session 8: Micromachines and wearable
Session 9: General

You are welcome to submit the extended versions of your conference work to this Special Issue for publication in our journal Micromachines, with a discount of 20% on the Article Processing Charge.

Prof. Dr. Ion Stiharu
Guest Editor

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Micromachines is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Published Papers (9 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

19 pages, 4278 KiB  
Article
Preparation and Characterization of Eco-Friendly Transparent Antibacterial Starch/Polyvinyl Alcohol Materials for Use as Wound-Dressing
by Mohammad Mohsen Delavari and Ion Stiharu
Micromachines 2022, 13(6), 960; https://doi.org/10.3390/mi13060960 - 17 Jun 2022
Cited by 9 | Viewed by 2394
Abstract
In this study, eco-friendly and transparent starch-based/polyvinyl alcohol/citric acid composite films are evaluated for their efficacy as wound dressing materials. The starch/polyvinyl alcohol (PVA) materials with added citric acid (0.46–1.83 wt%) and glycerol were made and handled based on the modified casting method. [...] Read more.
In this study, eco-friendly and transparent starch-based/polyvinyl alcohol/citric acid composite films are evaluated for their efficacy as wound dressing materials. The starch/polyvinyl alcohol (PVA) materials with added citric acid (0.46–1.83 wt%) and glycerol were made and handled based on the modified casting method. This new formulation decreases the amount of PVA used in the conventional preparation method. Citric acid ensures an appropriate antibacterial environment for wound-dressing materials. The mechanical, chemical, and surface morphological properties of such films were assessed and analyzed by tensile strength tests, UV–Vis spectrometry, swelling index, and scanning electron microscopy (SEM). Furthermore, the water vapor transmission (WVT) quantity was measured for an ideal wound-healing process to investigate an optimal moisture environment around the wound bed. Moreover, the pH level of the dressings was measured to examine the possibility of bacterial growth around these starch-based films. Additionally, the films’ in-vitro antibacterial activities were studied against the two most common Gram-positive and Gram-negative bacteria (Escherichia coli and Staphylococcus aureus). The new starch-based dressings demonstrated suitable degradation, antibacterial activity, fluid absorption, and adequate mechanical strength, representing wound-dressing materials’ vital features. Full article
(This article belongs to the Special Issue Selected Papers from ICMA2021)
Show Figures

Figure 1

10 pages, 2630 KiB  
Article
Facile Synthesis of 3D Printed Tailored Electrode for 3-Monochloropropane-1,2-Diol (3-MCPD) Sensing
by Farrah Aida Arris, Denesh Mohan and Mohd Shaiful Sajab
Micromachines 2022, 13(3), 383; https://doi.org/10.3390/mi13030383 - 27 Feb 2022
Cited by 4 | Viewed by 1813
Abstract
Additive manufacturing (AM) has allowed enormous advancement in technology and material development; thus, it requires attention in developing functionalized printed materials. AM can assist in efficiently manufacturing complex tailored electrodes for electrochemical sensing in the food industry. Herein, we used a commercial fused [...] Read more.
Additive manufacturing (AM) has allowed enormous advancement in technology and material development; thus, it requires attention in developing functionalized printed materials. AM can assist in efficiently manufacturing complex tailored electrodes for electrochemical sensing in the food industry. Herein, we used a commercial fused deposition modeling (FDM) filament of acrylonitrile butadiene styrene (ABS) for FDM 3D printing of a self-designed electrode with minimal time and cost compared to a commercial electrode. A graphene-based ABS conductive filament (ABS-G) was used to fabricate the conductive electrode in a dual-nozzle FDM 3D printer. The electrochemically conductive 3D printed electrode was characterized using cyclic voltammetry and tested against standard 3-monochloropropane-1,2-diol (3-MCPD) with known concentrations using an amperometric detection method. Results showed a basis for promising application to detect and quantify 3-MCPD, a food contaminant known for its carcinogenic potential. The fabrication of functionalized 3D printed polymer electrodes paves way for the development of complete 3D printable electrochemical sensors. Under optimal conditions, this newly synthesized electrochemical sensor exhibited sensitivity with a linear response range from 6.61 × 10−4 to 2.30 × 10−3 µg/mL with an estimated limit of detection of 3.30 × 10−4 µg/mL against 3-MCPD. Full article
(This article belongs to the Special Issue Selected Papers from ICMA2021)
Show Figures

Figure 1

14 pages, 3660 KiB  
Article
Passivated Porous Silicon Membranes and Their Application to Optical Biosensing
by Clara Whyte Ferreira, Roselien Vercauteren and Laurent A. Francis
Micromachines 2022, 13(1), 10; https://doi.org/10.3390/mi13010010 - 22 Dec 2021
Cited by 5 | Viewed by 2956
Abstract
A robust fabrication method for stable mesoporous silicon membranes using standard microfabrication techniques is presented. The porous silicon membranes were passivated through the atomic layer deposition of different metal oxides, namely aluminium oxide Al2O3, hafnium oxide HfO2 and [...] Read more.
A robust fabrication method for stable mesoporous silicon membranes using standard microfabrication techniques is presented. The porous silicon membranes were passivated through the atomic layer deposition of different metal oxides, namely aluminium oxide Al2O3, hafnium oxide HfO2 and titanium oxide TiO2. The fabricated membranes were characterized in terms of morphology, optical properties and chemical properties. Stability tests and optical probing noise level determination were also performed. Preliminary results using an Al2O3 passivated membranes for a biosensing application are also presented for selective optical detection of Bacillus cereus bacterial lysate. The biosensor was able to detect the bacterial lysate, with an initial bacteria concentration of 106 colony forming units per mL (CFU/mL), in less than 10 min. Full article
(This article belongs to the Special Issue Selected Papers from ICMA2021)
Show Figures

Figure 1

14 pages, 2577 KiB  
Article
Comparative Evaluation of Artificial Neural Networks and Data Analysis in Predicting Liposome Size in a Periodic Disturbance Micromixer
by Ixchel Ocampo, Rubén R. López, Sergio Camacho-León, Vahé Nerguizian and Ion Stiharu
Micromachines 2021, 12(10), 1164; https://doi.org/10.3390/mi12101164 - 28 Sep 2021
Cited by 7 | Viewed by 2410
Abstract
Artificial neural networks (ANN) and data analysis (DA) are powerful tools for supporting decision-making. They are employed in diverse fields, and one of them is nanotechnology; for example, in predicting silver nanoparticles size. To our knowledge, we are the first to use ANN [...] Read more.
Artificial neural networks (ANN) and data analysis (DA) are powerful tools for supporting decision-making. They are employed in diverse fields, and one of them is nanotechnology; for example, in predicting silver nanoparticles size. To our knowledge, we are the first to use ANN to predict liposome size (LZ). Liposomes are lipid nanoparticles used in different biomedical applications that can be produced in Dean-Forces-based microdevices such as the Periodic Disturbance Micromixer (PDM). In this work, ANN and DA techniques are used to build a LZ prediction model by using the most relevant variables in a PDM, the Flow Rate Radio (FRR), and the Total Flow Rate (TFR), and the temperature, solvents, and concentrations were kept constant. The ANN was designed in MATLAB and fed data from 60 experiments with 70% training, 15% validation, and 15% testing. For DA, a regression analysis was used. The model was evaluated; it showed a 0.98147 correlation coefficient for training and 0.97247 in total data compared with 0.882 obtained by DA. Full article
(This article belongs to the Special Issue Selected Papers from ICMA2021)
Show Figures

Figure 1

13 pages, 2961 KiB  
Communication
The Fabrication and Indentation of Cubic Silicon Carbide Diaphragm for Acoustic Sensing
by Siti Aisyah Zawawi, Azrul Azlan Hamzah, Burhanuddin Yeop Majlis and Faisal Mohd-Yasin
Micromachines 2021, 12(9), 1101; https://doi.org/10.3390/mi12091101 - 13 Sep 2021
Cited by 2 | Viewed by 1919
Abstract
In this study, 550 nm thick cubic silicon carbide square diaphragms were back etched from Si substrate. Then, indentation was carried out to samples with varying dimensions, indentation locations, and loads. The influence of three parameters is documented by analyzing load-displacement curves. It [...] Read more.
In this study, 550 nm thick cubic silicon carbide square diaphragms were back etched from Si substrate. Then, indentation was carried out to samples with varying dimensions, indentation locations, and loads. The influence of three parameters is documented by analyzing load-displacement curves. It was found that diaphragms with bigger area, indented at the edge, and low load demonstrated almost elastic behaviour. Furthermore, two samples burst and one of them displayed pop-in behaviour, which we determine is due to plastic deformation. Based on optimum dimension and load, we calculate maximum pressure for elastic diaphragms. This pressure is sufficient for cubic silicon carbide diaphragms to be used as acoustic sensors to detect poisonous gasses. Full article
(This article belongs to the Special Issue Selected Papers from ICMA2021)
Show Figures

Figure 1

17 pages, 4422 KiB  
Article
Sensitivity Analysis of a Portable Wireless PCB-MEMS Permittivity Sensor Node for Non-Invasive Liquid Recognition
by Javier Meléndez-Campos, Matias Vázquez-Piñón and Sergio Camacho-Leon
Micromachines 2021, 12(9), 1068; https://doi.org/10.3390/mi12091068 - 02 Sep 2021
Cited by 1 | Viewed by 3195
Abstract
Dielectric characteristics are useful to determine crucial properties of liquids and to differentiate between liquid samples with similar physical characteristics. Liquid recognition has found applications in a broad variety of fields, including healthcare, food science, and quality inspection, among others. This work demonstrates [...] Read more.
Dielectric characteristics are useful to determine crucial properties of liquids and to differentiate between liquid samples with similar physical characteristics. Liquid recognition has found applications in a broad variety of fields, including healthcare, food science, and quality inspection, among others. This work demonstrates the fabrication, instrumentation, and functionality of a portable wireless sensor node for the permittivity measurement of liquids that require characterization and differentiation. The node incorporates an interdigitated microelectrode array as a transducer and a microcontroller unit with radio communication electronics for data processing and transmission, which enable a wide variety of stand-alone applications. A laser-ablation-based microfabrication technique is applied to fabricate the microelectromechanical systems (MEMS) transducer on a printed circuit board (PCB) substrate. The surface of the transducer is covered with a thin layer of SU-8 polymer by spin coating, which prevents it from direct contact with the Cu electrodes and the liquid sample. This helps to enhance durability, avoid electrode corrosion and contamination of the liquid sample, and to prevent undesirable electrochemical reactions to arise. The transducer’s impedance was modeled as a Randles cell, having resistive and reactive components determined analytically using a square wave as stimuli, and a resistor as a current-to-voltage converter. To characterize the node sensitivity under different conditions, three different transducer designs were fabricated and tested for four different fluids, i.e., air, isopropanol, glycerin, and distilled water—achieving a sensitivity of 1.6965 +/− 0.2028 εr/pF. The use of laser ablation allowed the reduction of the transducer footprint while maintaining its sensitivity within an adequate value for the targeted applications. Full article
(This article belongs to the Special Issue Selected Papers from ICMA2021)
Show Figures

Graphical abstract

12 pages, 27988 KiB  
Article
Rapid Lipid Content Screening in Neochloris oleoabundans Utilizing Carbon-Based Dielectrophoresis
by Cynthia M. Galicia-Medina, Matías Vázquez-Piñón, Gibran S. Alemán-Nava, Roberto C. Gallo-Villanueva, Sergio O. Martínez-Chapa, Marc J. Madou, Sergio Camacho-León, Jonathan S. García-Pérez, Diego A. Esquivel-Hernández, Roberto Parra-Saldívar and Víctor H. Pérez-González
Micromachines 2021, 12(9), 1023; https://doi.org/10.3390/mi12091023 - 27 Aug 2021
Cited by 1 | Viewed by 3003
Abstract
In this study, we carried out a heterogeneous cytoplasmic lipid content screening of Neochloris oleoabundans microalgae by dielectrophoresis (DEP), using castellated glassy carbon microelectrodes in a PDMS microchannel. For this purpose, microalgae were cultured in nitrogen-replete (N+) and nitrogen-deplete (N−) suspensions to promote [...] Read more.
In this study, we carried out a heterogeneous cytoplasmic lipid content screening of Neochloris oleoabundans microalgae by dielectrophoresis (DEP), using castellated glassy carbon microelectrodes in a PDMS microchannel. For this purpose, microalgae were cultured in nitrogen-replete (N+) and nitrogen-deplete (N−) suspensions to promote low and high cytoplasmic lipid production in cells, respectively. Experiments were carried out over a wide frequency window (100 kHz–30 MHz) at a fixed amplitude of 7 VPP. The results showed a statistically significant difference between the dielectrophoretic behavior of N+ and N− cells at low frequencies (100–800 kHz), whereas a weak response was observed for mid- and high frequencies (1–30 MHz). Additionally, a finite element analysis using a 3D model was conducted to determine the dielectrophoretic trapping zones across the electrode gaps. These results suggest that low-cost glassy carbon is a reliable material for microalgae classification—between low and high cytoplasmic lipid content—through DEP, providing a fast and straightforward mechanism. Full article
(This article belongs to the Special Issue Selected Papers from ICMA2021)
Show Figures

Figure 1

17 pages, 29892 KiB  
Article
Photothermal Agarose Microfabrication Technology for Collective Cell Migration Analysis
by Mitsuru Sentoku, Hiromichi Hashimoto, Kento Iida, Masaharu Endo and Kenji Yasuda
Micromachines 2021, 12(9), 1015; https://doi.org/10.3390/mi12091015 - 26 Aug 2021
Cited by 3 | Viewed by 1987
Abstract
Agarose photothermal microfabrication technology is one of the micropatterning techniques that has the advantage of simple and flexible real-time fabrication even during the cultivation of cells. To examine the ability and limitation of the agarose microstructures, we investigated the collective epithelial cell migration [...] Read more.
Agarose photothermal microfabrication technology is one of the micropatterning techniques that has the advantage of simple and flexible real-time fabrication even during the cultivation of cells. To examine the ability and limitation of the agarose microstructures, we investigated the collective epithelial cell migration behavior in two-dimensional agarose confined structures. Agarose microchannels from 10 to 211 micrometer width were fabricated with a spot heating of a focused 1480 nm wavelength infrared laser to the thin agarose layer coated on the cultivation dish after the cells occupied the reservoir. The collective cell migration velocity maintained constant regardless of their extension distance, whereas the width dependency of those velocities was maximized around 30 micrometer width and decreased both in the narrower and wider microchannels. The single-cell tracking revealed that the decrease of velocity in the narrower width was caused by the apparent increase of aspect ratio of cell shape (up to 8.9). In contrast, the decrease in the wider channels was mainly caused by the increase of the random walk-like behavior of component cells. The results confirmed the advantages of this method: (1) flexible fabrication without any pre-designing, (2) modification even during cultivation, and (3) the cells were confined in the agarose geometry. Full article
(This article belongs to the Special Issue Selected Papers from ICMA2021)
Show Figures

Figure 1

10 pages, 2195 KiB  
Article
Fabrication of Microstructured Surface Topologies for the Promotion of Marine Bacteria Biofilm
by Ariadni Droumpali, Jörg Hübner, Lone Gram and Rafael Taboryski
Micromachines 2021, 12(8), 926; https://doi.org/10.3390/mi12080926 - 03 Aug 2021
Cited by 1 | Viewed by 2466
Abstract
Several marine bacteria of the Roseobacter group can inhibit other microorganisms and are especially antagonistic when growing in biofilms. This aptitude to naturally compete with other bacteria can reduce the need for antibiotics in large-scale aquaculture units, provided that their culture can be [...] Read more.
Several marine bacteria of the Roseobacter group can inhibit other microorganisms and are especially antagonistic when growing in biofilms. This aptitude to naturally compete with other bacteria can reduce the need for antibiotics in large-scale aquaculture units, provided that their culture can be promoted and controlled. Micropatterned surfaces may facilitate and promote the biofilm formation of species from the Roseobacter group, due to the increased contact between the cells and the surface material. Our research goal is to fabricate biofilm-optimal micropatterned surfaces and investigate the relevant length scales for surface topographies that can promote the growth and biofilm formation of the Roseobacter group of bacteria. In a preliminary study, silicon surfaces comprising arrays of pillars and pits with different periodicities, diameters, and depths were produced by UV lithography and deep reactive ion etching (DRIE) on polished silicon wafers. The resulting surface microscale topologies were characterized via optical profilometry and scanning electron microscopy (SEM). Screening of the bacterial biofilm on the patterned surfaces was performed using green fluorescent staining (SYBR green I) and confocal laser scanning microscopy (CLSM). Our results indicate that there is a correlation between the surface morphology and the spatial organization of the bacterial biofilm. Full article
(This article belongs to the Special Issue Selected Papers from ICMA2021)
Show Figures

Figure 1

Back to TopTop