Search for Articles:
Title / Keyword
Author / Affiliation / Email
Journal
Article Type
 
 
Advanced Search
 
Section
Special Issue
Volume
Issue
Number
Page
 
4.7
3.4
Journals
Micromachines
Special Issues
Advances in Microswimmers
share announcement

Advances in Microswimmers

A special issue of Micromachines (ISSN 2072-666X). This special issue belongs to the section "A：Physics".

Deadline for manuscript submissions: closed (30 June 2021) | Viewed by 30242

Special Issue Editor

Prof. Dr. Byung-Wook Park

E-Mail Website
Guest Editor
Civil/Environmental and Chemical Engineering & Materials Science and Engineering, Youngstown State University, Youngstown, OH, USA
Interests: microswimmers; biohybrid materials; biosensors; wearable bioelectronics; engineered living materials; drug delivery

Special Issue Information

Dear Colleagues,

Microswimmers are a novel research area, first demonstrated nearly two decades ago. Nano/micro-scale swimmers have attracted considerable attention because of their potential applications in targeted drug delivery, biosensors, medical imaging, and environmental remediation.  Propulsion mechanism of catalytic microsystems generally depends on the catalytic reactions to create active motions, while biohybrid microswimmers, incorporated with bacteria, algae and sperm cells, move by converting chemical energy to mechanical actuation. Even though various microswimmers have been developed and have showed demonstrations of their performance, the use of microswimmers still presents many challenges regarding biocompatibility, biodegradability, functionality, manipulation, and fabrication efficiency.  This special issue seeks to showcase research papers, short communications, and review articles that focus on recent progress on biohybrid and catalytic microswimmers and novel strategies addressing the challenges. More specifically, topics of interest include, but are not limited to, microswimmers with integrated multifunctional nano/microstructures for various applications such as drug delivery, environmental remediation, catalyst, mobile biosensors, electrochemical biosensors, medical imaging, smart actuators.

Prof. Byung-Wook Park
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.

Keywords

  • Microswimmer
  • Microrobot
  • Micromotor
  • Biohybrid material
  • Microorganisms
  • Cell
  • Catalytic reaction
  • Biosensors
  • Medical imaging
  • Bioimaging

Published Papers (6 papers)

Download All Papers
Order results
Result details
Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:

Research

Jump to: Review

19 pages, 1190 KiB  
Article
Geometric Methods for Efficient Planar Swimming of Copepod Nauplii
by Corey Shanbrom, Jonas Balisacan, George Wilkens and Monique Chyba
Micromachines 2021, 12(6), 706; https://doi.org/10.3390/mi12060706 - 16 Jun 2021
Viewed by 1847
Abstract
Copepod nauplii are larval crustaceans with important ecological functions. Due to their small size, they experience an environment of low Reynolds number within their aquatic habitat. Here we provide a mathematical model of a swimming copepod nauplius with two legs moving in a [...] Read more.
Copepod nauplii are larval crustaceans with important ecological functions. Due to their small size, they experience an environment of low Reynolds number within their aquatic habitat. Here we provide a mathematical model of a swimming copepod nauplius with two legs moving in a plane. This model allows for both rotation and two-dimensional displacement by the periodic deformation of the swimmer’s body. The system is studied from the framework of optimal control theory, with a simple cost function designed to approximate the mechanical energy expended by the copepod. We find that this model is sufficiently realistic to recreate behavior similar to those of observed copepod nauplii, yet much of the mathematical analysis is tractable. In particular, we show that the system is controllable, but there exist singular configurations where the degree of non-holonomy is non-generic. We also partially characterize the abnormal extremals and provide explicit examples of families of abnormal curves. Finally, we numerically simulate normal extremals and observe some interesting and surprising phenomena. Full article
(This article belongs to the Special Issue Advances in Microswimmers)
►▼ Show Figures

Figure 1

17 pages, 3014 KiB  
Article
Potential Whole-Cell Biosensors for Detection of Metal Using MerR Family Proteins from Enterobacter sp. YSU and Stenotrophomonas maltophilia OR02
by Georgina Baya, Stephen Muhindi, Valentine Ngendahimana and Jonathan Caguiat
Micromachines 2021, 12(2), 142; https://doi.org/10.3390/mi12020142 - 29 Jan 2021
Cited by 3 | Viewed by 3184
Abstract
Cell-based biosensors harness a cell’s ability to respond to the environment by repurposing its sensing mechanisms. MerR family proteins are activator/repressor switches that regulate the expression of bacterial metal resistance genes and have been used in metal biosensors. Upon metal binding, a conformational [...] Read more.
Cell-based biosensors harness a cell’s ability to respond to the environment by repurposing its sensing mechanisms. MerR family proteins are activator/repressor switches that regulate the expression of bacterial metal resistance genes and have been used in metal biosensors. Upon metal binding, a conformational change switches gene expression from off to on. The genomes of the multimetal resistant bacterial strains, Stenotrophomonas maltophilia Oak Ridge strain 02 (S. maltophilia 02) and Enterobacter sp. YSU, were recently sequenced. Sequence analysis and gene cloning identified three mercury resistance operons and three MerR switches in these strains. Transposon mutagenesis and sequence analysis identified Enterobacter sp. YSU zinc and copper resistance operons, which appear to be regulated by the protein switches, ZntR and CueR, respectively. Sequence analysis and reverse transcriptase polymerase chain reaction (RT-PCR) showed that a CueR switch appears to activate a S. maltophilia 02 copper transport gene in the presence of CuSO4 and HAuCl4·3H2O. In previous studies, genetic engineering replaced metal resistance genes with the reporter genes for β-galactosidase, luciferase or the green fluorescence protein (GFP). These produce a color change of a reagent, produce light, or fluoresce in the presence of ultraviolet (UV) light, respectively. Coupling these discovered operons with reporter genes has the potential to create whole-cell biosensors for HgCl2, ZnCl2, CuSO4 and HAuCl4·3H2O. Full article
(This article belongs to the Special Issue Advances in Microswimmers)
►▼ Show Figures

Figure 1

15 pages, 4307 KiB  
Article
Propulsion Mechanism of Flexible Microbead Swimmers in the Low Reynolds Number Regime
by Yan-Hom Li and Shao-Chun Chen
Micromachines 2020, 11(12), 1107; https://doi.org/10.3390/mi11121107 - 15 Dec 2020
Cited by 2 | Viewed by 2131
Abstract
A propulsion mechanism for a flexible microswimmer constructed from superparamagnetic microbeads with different diameters and subjected to an oscillating field was studied experimentally and theoretically herein. Various types of artificial swimmers with different bending patterns were fabricated to determine the flexibility and an [...] Read more.
A propulsion mechanism for a flexible microswimmer constructed from superparamagnetic microbeads with different diameters and subjected to an oscillating field was studied experimentally and theoretically herein. Various types of artificial swimmers with different bending patterns were fabricated to determine the flexibility and an effective waveform for a planar beating flagellum. Waveform evolutions for various swimmer configurations were studied to determine the flexible mechanism of the swimmers. A one-armed microswimmer can propel itself only if the friction of its wavelike body is anisotropic. A swimmer with a larger head and a stronger magnetic dipole moment with a flexible tail allows the bending wave to propagate from the head toward the tail to generate forward thrust. The oscillating head and tail do not simultaneously generate positive thrust all the time within a period of oscillation. To increase the propulsion for a bending swimmer, this study proposes a novel configuration for a microbead swimmer that ensures better swimming efficiency. The ratio of the oscillation amplitude of the head to the length of the swimmer (from 0.26 to 0.28) produces a faster swimmer. On the other hand, the swimmer is propelled more effectively if the ratio of the oscillation amplitude of the tail to the length of the swimmer is from 0.29 to 0.33. This study determined the optimal configuration for a flexible microbead swimmer that generates the greatest propulsion in a low Reynolds number environment. Full article
(This article belongs to the Special Issue Advances in Microswimmers)
►▼ Show Figures

Graphical abstract

15 pages, 4298 KiB  
Article
Localization and Actuation for MNPs Based on Magnetic Field-Free Point: Feasibility of Movable Electromagnetic Actuations
by Chan Kim, Jayoung Kim, Jong-Oh Park, Eunpyo Choi and Chang-Sei Kim
Micromachines 2020, 11(11), 1020; https://doi.org/10.3390/mi11111020 - 21 Nov 2020
Cited by 7 | Viewed by 2712
Abstract
Targeted drug delivery (TDD) based on magnetic nanoparticles (MNPs) and external magnetic actuation is a promising drug delivery technology compared to conventional treatments usually utilized in cancer therapy. However, the implementation of a TDD system at a clinical site based on considerations for [...] Read more.
Targeted drug delivery (TDD) based on magnetic nanoparticles (MNPs) and external magnetic actuation is a promising drug delivery technology compared to conventional treatments usually utilized in cancer therapy. However, the implementation of a TDD system at a clinical site based on considerations for the actual size of the human body requires a simplified structure capable of both external actuation and localization. To address these requirements, we propose a novel approach to localize drug carriers containing MNPs by manipulating the field-free point (FFP) mechanism in the principal magnetic field. To this end, we devise a versatile electromagnetic actuation (EMA) system for FFP generation based on four coils affixed to a movable frame. By the Biot–Savart law, the FFP can be manipulated by appropriately controlling the gradient field strength at the target area using the EMA system. Further, weighted-norm solutions are utilized to correct the positions of FFP to improve the accuracy of FFP displacement in the region of interest (ROI). As MNPs, ferrofluid is used to experiment with 2D and 3D localizations in a blocked phantom placed in the designed ROI. The resultant root mean square error of the localizations is observed to be approximately 1.4 mm in the 2D case and 1.6 mm in the 3D case. Further, the proposed movable EMA is verified to be capable of simultaneously scanning multiple points as well as the actuation and imaging of MNPs. Based on the success of the experiments in this study, further research is intended to be conducted in scale-up system development to design precise TDD systems at clinical sites. Full article
(This article belongs to the Special Issue Advances in Microswimmers)
►▼ Show Figures

Figure 1

Review

Jump to: Research

24 pages, 5861 KiB  
Review
Recent Advances in Microswimmers for Biomedical Applications
by Ada-Ioana Bunea and Rafael Taboryski
Micromachines 2020, 11(12), 1048; https://doi.org/10.3390/mi11121048 - 27 Nov 2020
Cited by 47 | Viewed by 6862
Abstract
Microswimmers are a rapidly developing research area attracting enormous attention because of their many potential applications with high societal value. A particularly promising target for cleverly engineered microswimmers is the field of biomedical applications, where many interesting examples have already been reported for [...] Read more.
Microswimmers are a rapidly developing research area attracting enormous attention because of their many potential applications with high societal value. A particularly promising target for cleverly engineered microswimmers is the field of biomedical applications, where many interesting examples have already been reported for e.g., cargo transport and drug delivery, artificial insemination, sensing, indirect manipulation of cells and other microscopic objects, imaging, and microsurgery. Pioneered only two decades ago, research studies on the use of microswimmers in biomedical applications are currently progressing at an incredibly fast pace. Given the recent nature of the research, there are currently no clinically approved microswimmer uses, and it is likely that several years will yet pass before any clinical uses can become a reality. Nevertheless, current research is laying the foundation for clinical translation, as more and more studies explore various strategies for developing biocompatible and biodegradable microswimmers fueled by in vivo-friendly means. The aim of this review is to provide a summary of the reported biomedical applications of microswimmers, with focus on the most recent advances. Finally, the main considerations and challenges for clinical translation and commercialization are discussed. Full article
(This article belongs to the Special Issue Advances in Microswimmers)
►▼ Show Figures

Figure 1

17 pages, 8494 KiB  
Review
Sperm Cell Driven Microrobots—Emerging Opportunities and Challenges for Biologically Inspired Robotic Design
by Ajay Vikram Singh, Mohammad Hasan Dad Ansari, Mihir Mahajan, Shubhangi Srivastava, Shubham Kashyap, Prajjwal Dwivedi, Vaibhav Pandit and Uma Katha
Micromachines 2020, 11(4), 448; https://doi.org/10.3390/mi11040448 - 23 Apr 2020
Cited by 67 | Viewed by 12632
Abstract
With the advent of small-scale robotics, several exciting new applications like Targeted Drug Delivery, single cell manipulation and so forth, are being discussed. However, some challenges remain to be overcome before any such technology becomes medically usable; among which propulsion and biocompatibility are [...] Read more.
With the advent of small-scale robotics, several exciting new applications like Targeted Drug Delivery, single cell manipulation and so forth, are being discussed. However, some challenges remain to be overcome before any such technology becomes medically usable; among which propulsion and biocompatibility are the main challenges. Propulsion at micro-scale where the Reynolds number is very low is difficult. To overcome this, nature has developed flagella which have evolved over millions of years to work as a micromotor. Among the microscopic cells that exhibit this mode of propulsion, sperm cells are considered to be fast paced. Here, we give a brief review of the state-of-the-art of Spermbots—a new class of microrobots created by coupling sperm cells to mechanical loads. Spermbots utilize the flagellar movement of the sperm cells for propulsion and as such do not require any toxic fuel in their environment. They are also naturally biocompatible and show considerable speed of motion thereby giving us an option to overcome the two challenges of propulsion and biocompatibility. The coupling mechanisms of physical load to the sperm cells are discussed along with the advantages and challenges associated with the spermbot. A few most promising applications of spermbots are also discussed in detail. A brief discussion of the future outlook of this extremely promising category of microrobots is given at the end. Full article
(This article belongs to the Special Issue Advances in Microswimmers)
►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less
Select all
Export citation of selected articles as:
 
Displaying articles 1-6
Back to TopTop