The functionalities of the untethered miniature swimming robots significantly decrease as the robot size becomes smaller, due to limitations of feasible miniaturized on-board components. Here we ...propose an untethered jellyfish-inspired soft millirobot that could realize multiple functionalities in moderate Reynolds number by producing diverse controlled fluidic flows around its body using its magnetic composite elastomer lappets, which are actuated by an external oscillating magnetic field. We particularly investigate the interaction between the robot's soft body and incurred fluidic flows due to the robot's body motion, and utilize such physical interaction to achieve different predation-inspired object manipulation tasks. The proposed lappet kinematics can inspire other existing jellyfish-like robots to achieve similar functionalities at the same length and time scale. Moreover, the robotic platform could be used to study the impacts of the morphology and kinematics changing in ephyra jellyfish.
Small‐scale magnetic soft‐bodied robots based on biocompatible and biodegradable materials are essential for their potential high‐impact minimally invasive medical applications inside the human body. ...Therefore, a strategy for fully biodegradable untethered soft millirobots with encoded 3D magnetic anisotropy for their static or dynamic shape programming is presented. Such a robot body is comprised of a porcine extracellular matrix‐derived collagen‐based hydrogel network with embedded superparamagnetic iron oxide nanoparticles (SPIONs). 3D magnetization programming inside the hydrogel body is achieved by directionally self‐assembled SPION chains using an external permanent magnet. As a proof‐of‐concept demonstration, a hydrogel milli‐gripper that can undergo flexible and reversible shape deformations inside glycerol and biologically relevant liquid media is presented. The gripper can perform cargo grabbing, transportation by rolling, and release by controlling magnetic field inputs. These milli‐grippers can be completely degraded by the matrix metalloproteinase‐2 enzyme in physiologically relevant concentrations. Furthermore, biocompatibility tests using human umbilical cord vein endothelial cells with the degradation products of the grippers demonstrate no acute toxicity. The approach offers a facile fabrication strategy for designing biocompatible and biodegradable soft robots using nanocomposite materials with programmable 3D magnetic anisotropy toward future medical applications.
A biodegradable magnetic milli‐gripper is developed by creating a 3D magnetic profile in a gelatin hydrogel matrix using directionally self‐assembled superparamagnetic iron oxide nanoparticle chains. It can undergo reversible shape deformations and perform cargo grasping and transportation tasks under controlled magnetic fields. The milli‐gripper can be completely degraded by the matrix metalloproteinase‐2 enzyme in physiologically relevant concentrations.
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.
Liquid crystal elastomers exhibit large reversible strain and programmable shape transformations, enabling various applications in soft robotics, dynamic optics, and programmable origami and ...kirigami. The morphing modes of these materials depend on both their geometries and director fields. In two dimensions, a pixel-by-pixel design has been accomplished to attain more flexibility over the spatial resolution of the liquid crystal response. Here we generalize this idea in two steps. First, we create independent, cubic light-responsive voxels, each with a predefined director field orientation. Second, these voxels are in turn assembled to form lines, grids, or skeletal structures that would be rather difficult to obtain from an initially connected material sample. In this way, the orientation of the director fields can be made to vary at voxel resolution to allow for programmable optically- or thermally-triggered anisotropic or heterogeneous material responses and morphology changes in three dimensions that would be impossible or hard to implement otherwise.
Magnetically driven wireless miniature devices have become promising recently in healthcare, information technology, and many other fields. However, they lack advanced fabrication methods to go down ...to micrometer length scales with heterogeneous functional materials, complex three-dimensional (3D) geometries, and 3D programmable magnetization profiles. To fill this gap, we propose a molding-integrated direct laser writing-based microfabrication approach in this study and showcase its advanced enabling capabilities with various proof-of-concept functional microdevice prototypes. Unique motions and functionalities, such as metachronal coordinated motion, fluid mixing, function reprogramming, geometrical reconfiguring, multiple degrees-of-freedom rotation, and wireless stiffness tuning are exemplary demonstrations of the versatility of this fabrication method. Such facile fabrication strategy can be applied toward building next-generation smart microsystems in healthcare, robotics, metamaterials, microfluidics, and programmable matter.
Shape-programmable magnetic soft matter Lum, Guo Zhan; Ye, Zhou; Dong, Xiaoguang ...
Proceedings of the National Academy of Sciences,
10/2016, Letnik:
113, Številka:
41
Journal Article
Recenzirano
Odprti dostop
Shape-programmable matter is a class of active materials whose geometry can be controlled to potentially achieve mechanical functionalities beyond those of traditional machines. Among these ...materials, magnetically actuated matter is particularly promising for achieving complex time-varying shapes at small scale (overall dimensions smaller than 1 cm). However, previous work can only program these materials for limited applications, as they rely solely on human intuition to approximate the required magnetization profile and actuating magnetic fields for their materials. Here, we propose a universal programming methodology that can automatically generate the required magnetization profile and actuating fields for soft matter to achieve new time-varying shapes. The universality of the proposed method can therefore inspire a vast number of miniature soft devices that are critical in robotics, smart engineering surfaces andmaterials, and biomedical devices. Our proposedmethod includes theoretical formulations, computational strategies, and fabrication procedures for programming magnetic soft matter. The presented theory and computational method are universal for programming 2D or 3D time-varying shapes, whereas the fabrication technique is generic only for creating planar beams. Based on the proposed programming method, we created a jellyfish-like robot, a spermatozoid-like undulating swimmer, and an artificial cilium that couldmimic the complex beating patterns of its biological counterpart.
Stimuli‐responsive and active materials promise radical advances for many applications. In particular, soft magnetic materials offer precise, fast, and wireless actuation together with versatile ...functionality, while liquid crystal elastomers (LCEs) are capable of large reversible and programmable shape‐morphing with high work densities in response to various environmental stimuli, e.g., temperature, light, and chemical solutions. Integrating the orthogonal stimuli‐responsiveness of these two kinds of active materials could potentially enable new functionalities and future applications. Here, magnetic microparticles (MMPs) are embedded into an LCE film to take the respective advantages of both materials without compromising their independent stimuli‐responsiveness. This composite material enables reconfigurable magnetic soft miniature machines that can self‐adapt to a changing environment. In particular, a miniature soft robot that can autonomously alter its locomotion mode when it moves from air to hot liquid, a vine‐like filament that can sense and twine around a support, and a light‐switchable magnetic spring are demonstrated. The integration of LCEs and MMPs into monolithic structures introduces a new dimension in the design of soft machines and thus greatly enhances their use in applications in complex environments, especially for miniature soft robots, which are self‐adaptable to environmental changes while being remotely controllable.
A liquid crystal elastomer material with embedded ferromagnetic microparticles takes advantage of both magnetic and thermal stimuli‐responsiveness. Such a monolithic soft material enables reconfigurable magnetic soft miniature machines that self‐adapt to changing environmental conditions. The hybrid material introduces a multi‐modal actuation and physical intelligence capability for wireless soft machines.
Purpose
Asprosin was a newly identified secreted hormone which could induce hepatic glucose release. Since asprosin closely associated with the risk factors of diabetic kidney disease (DKD), ...including hyperglycemia, insulin resistance and inflammation, the present study aimed to investigate the relationship between circulating asprosin levels and the early stage of DKD.
Methods
30 subjects with normal glucose tolerance (NGT), 42 type 2 diabetes (T2DM) patients without DKD and 33 T2DM patients with early stage of DKD were recruited. Early stage of DKD was defined as two consecutive measurements of urinary albumin-to-creatinine ratio (UACR) 30–299 mg/g and estimated glomerular filtration rate (eGFR) ≥ 60 mL/min/1.73m
2
. Multiple linear regression analysis was conducted to explore the associations of circulating asprosin levels with eGFR and UACR. Multiple logistic regression analysis was used to determine the association of circulating asprosin levels with the early stage of DKD.
Results
Circulating asprosin levels in Non-DKD and DKD groups were significantly higher than that in NGT group and the DKD group showed the highest levels. Circulating asprosin levels negatively correlated with eGFR (
r
= − 0.311,
P
= 0.007) and positively correlated with UACR (
r
= 0.345,
P
= 0.002) in T2DM patients. Even after multivariable adjustment, circulating asprosin levels were closely associated with eGFR and UACR and significantly increased ORs for early stage of DKD (OR = 3.973,
P
= 0.001).
Conclusion
Circulating asprosin levels were increased in T2DM and associated with the early stage of DKD. The specific role of asprosin in DKD needs further investigation.
To translate the Stressors in Breast Cancer Scale (SBCS) from English to Chinese and assess its psychometric properties.
The Brislin's translation model was applied to perform forward translation, ...back translation, cross-cultural adaptation, Whereas the Chinese version of the SBCS was formed by conducting pre-testing. A cohort of 878 breast cancer patients participated in this methodological study. Content validity, construct validity, convergent validity, discriminant validity, and criterion-related validity were used to establish validity. Internal consistency reliability, split-half reliability, and test-retest reliability were used to establish reliability.
The final scale contained five dimensions and 24 items, including interpersonal relationship and healthcare strains, worries and concerns about the future, physical appearance and sex strains, daily difficulties and health. The average content validity index of the scale was 0.975. The goodness-of-fit index (χ2/DF = 2.416, RMSEA = 0.057, GFI = 0.896, CFI = 0.947, IFI = 0.947, and TLI = 0.939) indicated that the model was well-fitted. The composite reliability (CR) of the dimensions ranged from 0.825 to 0.934, the average variance extracted (AVE) ranged from 0.539 to 0.712, and the correlation coefficients of each dimension with the other dimensions were less than the square root of the AVE for that dimension. The Criterion-related validity was 0.511. The Cronbach's alpha was 0.938, and the dimensions ranged from 0.779 to 0.900. Split-half reliability was 0.853, with dimensions ranging from 0.761 to 0.892. Test-retest reliability was 0.855.
The Chinese version of the SBCS has good reliability and validity, which can be applied to the assessment of stressors in breast cancer patients in China.
Small-scale soft-bodied machines that respond to externally applied magnetic field have attracted wide research interest because of their unique capabilities and promising potential in a variety of ...fields, especially for biomedical applications. When the size of such machines approach the sub-millimeter scale, their designs and functionalities are severely constrained by the available fabrication methods, which only work with limited materials, geometries, and magnetization profiles. To free such constraints, here, we propose a bottom-up assembly-based 3D microfabrication approach to create complex 3D miniature wireless magnetic soft machines at the milli- and sub-millimeter scale with arbitrary multimaterial compositions, arbitrary 3D geometries, and arbitrary programmable 3D magnetization profiles at high spatial resolution. This approach helps us concurrently realize diverse characteristics on the machines, including programmable shape morphing, negative Poisson's ratio, complex stiffness distribution, directional joint bending, and remagnetization for shape reconfiguration. It enlarges the design space and enables biomedical device-related functionalities that are previously difficult to achieve, including peristaltic pumping of biological fluids and transport of solid objects, active targeted cargo transport and delivery, liquid biopsy, and reversible surface anchoring in tortuous tubular environments withstanding fluid flows, all at the sub-millimeter scale. This work improves the achievable complexity of 3D magnetic soft machines and boosts their future capabilities for applications in robotics and biomedical engineering.
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