Fabrication and Characterization of Magnetic Microrobots for Three-Dimensional Cell Culture and Targeted Transportation
TL;DR: Three-dimensional porous structures fabricated with an SU-8 photoresist using a 3D laser lithography system for targeted cell transportation and human embryonic kidney 239 cells are cultivated in the microrobot.
Abstract: Magnetically manipulated microrobots are demonstrated for targeted cell transportation. Full three-dimensional (3D) porous structures are fabricated with an SU-8 photoresist using a 3D laser lithography system. Nickel and titanium are deposited as a magnetic material and biocompatible material, respectively. The fabricated microrobots are controlled in the fluid by external magnetic fields. Human embryonic kidney 239 (HEK 239) cells are cultivated in the microrobot to show the possibility for targeted cell transportation.
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01 Feb 2015
TL;DR: A comprehensive review of the current advances in biomedical untethered mobile milli/microrobots and discusses the existing challenges and emerging concepts associated with designing such a miniaturized robot for operation inside a biological environment for biomedical applications.
Abstract: Untethered robots miniaturized to the length scale of millimeter and below attract growing attention for the prospect of transforming many aspects of health care and bioengineering. As the robot size goes down to the order of a single cell, previously inaccessible body sites would become available for high-resolution in situ and in vivo manipulations. This unprecedented direct access would enable an extensive range of minimally invasive medical operations. Here, we provide a comprehensive review of the current advances in biomedical untethered mobile milli/microrobots. We put a special emphasis on the potential impacts of biomedical microrobots in the near future. Finally, we discuss the existing challenges and emerging concepts associated with designing such a miniaturized robot for operation inside a biological environment for biomedical applications.
624 citations
Cites methods from "Fabrication and Characterization of..."
...who designed a cage shape microrobot which is fabricated by stereolithography of negative tone photoresist [107]....
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566 citations
TL;DR: In vivo imaging and actuation of a swarm of magnetic helical microswimmers by external magnetic fields in deep tissue is demonstrated for the first time, yielding a generation of micrometer-scale transporters with numerous applications in biomedicine including synthetic biology, assisted fertilization, and drug/gene delivery.
Abstract: In vivo imaging and actuation of a swarm of magnetic helical microswimmers by external magnetic fields (less than 10 mT) in deep tissue is demonstrated for the first time. This constitutes a major milestone in the field, yielding a generation of micrometer-scale transporters with numerous applications in biomedicine including synthetic biology, assisted fertilization, and drug/gene delivery.
423 citations
24 Apr 2019
TL;DR: A method for patterning hard magnetic microparticles in an elastomer matrix based on ultraviolet (UV) lithography, which uses controlled reorientation of magnetic particles and selective exposure to UV light to encode magnetic particles in planar materials with arbitrary 3D orientation with a geometrical feature size as small as 100 micrometers.
Abstract: Flexible magnetic small-scale robots use patterned magnetization to achieve fast transformation into complex three-dimensional (3D) shapes and thereby achieve locomotion capabilities and functions. These capabilities address current challenges for microrobots in drug delivery, object manipulation, and minimally invasive procedures. However, possible microrobot designs are limited by the existing methods for patterning magnetic particles in flexible materials. Here, we report a method for patterning hard magnetic microparticles in an elastomer matrix. This method, based on ultraviolet (UV) lithography, uses controlled reorientation of magnetic particles and selective exposure to UV light to encode magnetic particles in planar materials with arbitrary 3D orientation with a geometrical feature size as small as 100 micrometers. Multiple planar microrobots with various sizes, different geometries, and arbitrary magnetization profiles can be fabricated from a single precursor in one process. Moreover, a 3D magnetization profile allows higher-order and multi-axis bending, large-angle bending, and combined bending and torsion in one sheet of polymer, creating previously unachievable shape changes and microrobotic locomotion mechanisms such as multi-arm power grasping and multi-legged paddle crawling. A physics-based model is also presented as a design tool to predict the shape changes under magnetic actuation.
394 citations
Cites background from "Fabrication and Characterization of..."
...Although these robots have no more than five actuated degrees of freedom under a magnetic field, their geometries are designed to convert simple translation and rotation into functional motions for applications such as targeted drug delivery (17–20), cell culture (21), assisted fertilization (22), and noninvasive medical intervention inside the vascular system (23)....
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...Electrodeposition of magnetic particles on lithographically printed microstructures (18, 21, 22) Soft 3D No N/A...
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TL;DR: Recent developments on fuel-free micro-/nanomotors (powered by various external stimuli such as light, magnetic, electric, or ultrasonic fields) are summarized, ranging from fabrication to propulsion mechanisms.
Abstract: Inspired by the swimming of natural microorganisms, synthetic micro-/nanomachines, which convert energy into movement, are able to mimic the function of these amazing natural systems and help humanity by completing environmental and biological tasks. While offering autonomous propulsion, conventional micro-/nanomachines usually rely on the decomposition of external chemical fuels (e.g., H_2O_2), which greatly hinders their applications in biologically relevant media. Recent developments have resulted in various micro-/nanomotors that can be powered by biocompatible fuels. Fuel-free synthetic micro-/nanomotors, which can move without external chemical fuels, represent another attractive solution for practical applications owing to their biocompatibility and sustainability. Here, recent developments on fuel-free micro-/nanomotors (powered by various external stimuli such as light, magnetic, electric, or ultrasonic fields) are summarized, ranging from fabrication to propulsion mechanisms. The applications of these fuel-free micro-/nanomotors are also discussed, including nanopatterning, targeted drug/gene delivery, cell manipulation, and precision nanosurgery. With continuous innovation, future autonomous, intelligent and multifunctional fuel-free micro-/nanomachines are expected to have a profound impact upon diverse biomedical applications, providing unlimited opportunities beyond one's imagination.
312 citations
References
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TL;DR: Weisskopf as mentioned in this paper presented a transparencies of a tall rectangular transparent vessel of corn syrup, projected by an overhead projector turned on its side, which was itself a slightly edited transcript of a tape.
Abstract: Editor’s note: This is a reprint (slightly edited) of a paper of the same title that appeared in the book Physics and Our World: A Symposium in Honor of Victor F. Weisskopf, published by the American Institute of Physics (1976). The personal tone of the original talk has been preserved in the paper, which was itself a slightly edited transcript of a tape. The figures reproduce transparencies used in the talk. The demonstration involved a tall rectangular transparent vessel of corn syrup, projected by an overhead projector turned on its side. Some essential hand waving could not be reproduced.
3,906 citations
TL;DR: The aim of this review is to provide a comprehensive survey of the technological state of the art in medical microrobots, to explore the potential impact of medical micRORobots and inspire future research in this field.
Abstract: Microrobots have the potential to revolutionize many aspects of medicine. These untethered, wirelessly controlled and powered devices will make existing therapeutic and diagnostic procedures less invasive and will enable new procedures never before possible. The aim of this review is threefold: first, to provide a comprehensive survey of the technological state of the art in medical microrobots; second, to explore the potential impact of medical microrobots and inspire future research in this field; and third, to provide a collection of valuable information and engineering tools for the design of medical microrobots.
1,580 citations
TL;DR: ABF swimmers represent the first demonstration of microscopic artificial swimmers that use helical propulsion and are of interest in fundamental research and for biomedical applications.
Abstract: Inspired by the natural design of bacterial flagella, we report artificial bacterial flagella (ABF) that have a comparable shape and size to their organic counterparts and can swim in a controllable fashion using weak applied magnetic fields. The helical swimmer consists of a helical tail resembling the dimensions of a natural flagellum and a thin soft-magnetic “head” on one end. The swimming locomotion of ABF is precisely controlled by three orthogonal electromagnetic coil pairs. Microsphere manipulation is performed, and the thrust force generated by an ABF is analyzed. ABF swimmers represent the first demonstration of microscopic artificial swimmers that use helical propulsion. Self-propelled devices such as these are of interest in fundamental research and for biomedical applications.
1,040 citations
TL;DR: A simple and general fabrication method for helical swimming micromachines by direct laser writing and e-beam evaporation is demonstrated and the magnetic helical devices exhibit varying magnetic shape anisotropy, yet always generate corkscrew motion using a rotating magnetic field.
Abstract: A simple and general fabrication method for helical swimming micromachines by direct laser writing and e-beam evaporation is demonstrated. The magnetic helical devices exhibit varying magnetic shape anisotropy, yet always generate corkscrew motion using a rotating magnetic field. They also exhibit good swimming performance and are capable of pick-and-place micromanipulation in 3D. Cytotoxicity of the devices was investigated using mouse myoblasts. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
962 citations
01 Jan 1975
TL;DR: The attachment of cells to the polylysine-treated surfaces can be exploited for a variety of experimental manipulations and is found to be the case for nuclei isolated from sea urchin embryos and for the microtubules of flagella, which are well displayed after the membrane has been disrupted by Triton X-100.
Abstract: Cells of many kinds adhere firmly to glass or plastic surfaces which have been pretreated with polylysine. The attachment takes place as soon as the cells make contact with the surfaces, and the flattening of the cells against the surfaces is quite rapid. Cells which do not normally adhere to solid surfaces, such as sea urchin eggs, attach as well as cells which normally do so, such as amebas or mammalian cells in culture. The adhesion is interpreted simply as the interaction between the polyanionic cell surfaces and the polycationic layer of adsorbed polylysine. The attachment of cells to the polylysine-treated surfaces can be exploited for a variety of experimental manipulations. In the preparation of samples for scanning or transmission electron microscopy, the living material may first be attached to a polylysine- coated plate or grid, subjected to some experimental treatment (fertilization of an egg, for example), then transferred rapidly to fixative and further passed through processing for observation; each step involves only the transfer of the plate or grid from one container to the next. The cells are not detached. The adhesion of the cell may be so firm that the body of the cell may be sheared away, leaving attached a patch of cell surface, face up, for observation of its inner aspect. For example, one may observe secretory vesicles on the inner face of the surface (3) or may study the association of filaments with the inner surface (Fig. 1). Subcellular structures may attach to the polylysine-coated surfaces. So far, we have found this to be the case for nuclei isolated from sea urchin embryos and for the microtubules of flagella, which are well displayed after the membrane has been disrupted by Triton X-100 (Fig. 2).
805 citations