To add more functionalities and overcome the limitation in conventional soft robots, highly anisotropic soft actuators with color shifting function during actuation is demonstrated for the first ...time. The electrothermally operating soft actuators with installed transparent metal nanowire percolation network heater allow easy programming of their actuation direction and instantaneous visualization of temperature changes through color change. Due to the unique direction dependent coefficient of thermal expansion mismatch, the suggested actuator demonstrates a highly anisotropic and reversible behavior with very large bending curvature (2.5 cm−1) at considerably low temperature (≈40 °C) compared to the previously reported electrothermal soft actuators. The mild operating heat condition required for the maximum curvature enables the superior long‐term stability during more than 10 000 operating cycles. Also, the optical transparency of the polymer bilayer and metal nanowire percolation network heater allow the incorporation of the thermochromic pigments to fabricate color‐shifting actuators. As a proof‐of‐concept, various color‐shifting biomimetic soft robots such as color‐shifting blooming flower, fluttering butterfly, and color‐shifting twining tendril are demonstrated. The developed color‐shifting anisotropic soft actuator is expected to open new application fields and functionalities overcoming the limitation of current soft robots.
A color‐changing soft actuator is developed for soft robot applications. The thermal energy from a metal nanowire percolation network heater induces anisotropic large deformation as well as the color change of the thin film actuator. As a proof‐of‐concept, various biomimetic transparent soft robots such as color‐shifting blooming flower a, fluttering butterflies, and color‐shifting twining tendrils are demonstrated.
During the early months of COVID‐19, many people in the US turned to charitable crowdfunding to seek and provide assistance. Little is known about the needs, hopes or experiences that motivated US ...pandemic crowdfunding and how these were correlated with campaign success. This study uses a mixed‐methods data analysis of a randomised cluster sample of 919 US GoFundMe campaigns during the first 7 months of the pandemic. Overall, most campaigns performed poorly, and 38% got no donations at all. The largest proportion of campaigns aimed to address individual, acute financial struggles, often arising from considerable challenges accessing or qualifying for government assistance. These campaigns, as well as those involving campaigners and beneficiaries of colour, tended to be least successful. Qualitative thematic analysis revealed three key crowdfunding motivations that reflect individualistic, agentive responses to the pandemic: struggling, helping and adapting. These motivations reveal a shift away from social suffering and collective mobilisation and towards largely individualised efforts of survival as digital crowdfunding becomes a key domain of crisis response. Crowdfunding platforms are playing an increasingly important role in mediating and influencing individual and collective responses to crisis, which has important political ramifications for how societies perceive and address health emergencies.
Jumping on water is a unique locomotion mode found in semi-aquatic arthropods, such as water striders. To reproduce this feat in a surface tension–dominant jumping robot, we elucidated the ...hydrodynamics involved and applied them to develop a bio-inspired impulsive mechanism that maximizes momentum transfer to water. We found that water striders rotate the curved tips of their legs inward at a relatively low descending velocity with a force just below that required to break the water surface (144 millinewtons/meter). We built a 68-milligram at-scale jumping robotic insect and verified that it jumps on water with maximum momentum transfer. The results suggest an understanding of the hydrodynamic phenomena used by semi-aquatic arthropods during water jumping and prescribe a method for reproducing these capabilities in artificial systems.
Recent research progress of relieving discomfort between electronics and human body involves serpentine designs, ultrathin films, and extraordinary properties of nanomaterials. However, these ...strategies addressed thus far each face own limitation for achieving desired form of electronic-skin applications. Evenly matched mechanical properties anywhere on the body and imperceptibility of electronics are two essentially required characteristics for future electronic-skin (E-skin) devices. Yet accomplishing these two main properties simultaneously is still very challenging. Hence, we propose a novel fabrication method to introduce kirigami approach to pattern a highly conductive and transparent electrode into diverse shapes of stretchable electronics with multivariable configurability for E-skin applications. These kirigami engineered patterns impart tunable elasticity to the electrodes, which can be designed to intentionally limit strain or grant ultrastretchability depending on applications over the range of 0 to over 400% tensile strain with strain-invariant electrical property and show excellent strain reversibility even after 10 000 cycles stretching while exhibiting high optical transparency (>80%). The versatility of this work is demonstrated by ultrastretchable transparent kirigami heater for personal thermal management and conformal transparent kirigami electrophysiology sensor for continuous health monitoring of human body conditions. Finally, by integrating E-skin sensors with quadrotor drones, we have successfully demonstrated human-machine-interface using our stretchable transparent kirigami electrodes.
During the first seven months of the COVID-19 pandemic, more than 175,000 crowdfunding campaigns were established in the US for coronavirus-related needs using the platform GoFundMe. Though ...charitable crowdfunding has been popular in recent years, the widespread creation of COVID-19 related campaigns points to potential shifts in how the platform is being used, and the volume of needs users have brought to the site during a profound economic, social, and epidemiological crisis. This study offers a systematic examination of the scope and impacts of COVID-19 related crowdfunding in the early months of the pandemic and assesses how existing social and health inequities shaped crowdfunding use and outcomes. Using data collected from all US-based GoFundMe campaigns mentioning COVID or coronavirus, we used descriptive analysis and a series of negative binomial and linear models to assess the contributions of demographic factors and COVID-19 impacts to campaign creation and outcome. We find significant evidence of growing inequalities in outcomes for campaigners. We find that crowdfunding provides substantially higher benefits in wealthier counties with higher levels of education. People from these areas are more likely to initiate campaigns in response to adverse health and economic impacts of COVID-19, and they also receive more funding compared to people living in areas with lower income and education. Modeling also indicates differential outcomes based on the racial and ethnic composition of county population, though without more detail about who is creating and funding campaigns we cannot explain causality. A targeted qualitative analysis of the top earning COVID-19 campaigns offers further evidence of how user privilege and corporate practices contribute to highly unequal outcomes. Taken together, these findings demonstrate how a market-oriented digital technology used to respond to large-scale crisis can exacerbate inequalities and further benefit already privileged groups.
•Americans created over 175,000 COVID-19 related campaigns on GoFundMe in the first half of 2020.•More than 40% of COVID-19 related campaigns raised no money at all.•With high levels of inequality among campaigns, the top 1% of campaigns earned nearly 25% of all money raised.•Areas with high levels of education, rather than highest needs, had more campaigns.•Crowdfunding was most effective in areas with both high levels of education and high incomes.
Aim
To determine the tensile load capacity (TLC) and the tearing characteristics for interrupted and vertical mattress sutures with different insertion points from the wound margin, and the effect of ...the bite size when using vertical mattress sutures.
Materials and Methods
A total of 120 gingiva and lining mucosa samples obtained from pig jaws were divided into groups according to the suturing technique (interrupted and vertical mattress sutures), distance of the insertion points from the wound margin (margin, 1, 3, and 5 mm) and bite size (1, 3, and 5 mm). The TLC of the suture and the tearing characteristics were evaluated using a tensile tester device.
Results
The TLC was significantly higher for vertical mattress sutures than for interrupted sutures regardless of the distance of the insertion points from the wound margin (intergroup p < .001). This distance significantly influenced the TLC for vertical mattress sutures (p < .05) but not for interrupted sutures (p > .05). Testing the tearing characteristics revealed that no tissue tearing occurred in groups when the insertion points were more than 3 mm from the wound margin.
Conclusion
The TLC is higher for vertical mattress sutures than for interrupted sutures, and it increases when the insertion points are farther from the wound margin.
In this paper, we present a milliscale-integrated jumping-crawling robot that can adjust its launch trajectory and upright itself. This multimodal robot shows an enhanced performance of overcoming ...obstacles compared with a robot with a single locomotion mode. To make this possible, the robot uses a newly developed jumping module with improved energy storing capacity and a height-adjustable active clutch. The jumping module utilizes both linear springs and torsional springs to maximize the energy-storing capacity under the given limit of structural robustness. To adjust the quantity of stored energy and release the energy at any state, an active clutch mechanism based on a single dc motor is developed, which enables the robot to control both jump timing and height. Also, an active shell allows the robot to upright itself after landing and to continue jumping and crawling. The jumping module and the shell are integrated with the lightweight VelociRoACH crawler. To show the usability in real-world applications, the integrated jumping-crawling robot is tested on the cluttered terrain. In result, the robot reaches a target using jumping, crawling, and self-righting.
•We develop harmonic background field extension based on physics-informed GAN.•Our method mitigates propagated error from background field removal in limited FOV.•Physics-informed loss shows improved ...results of extended harmonic field.•Outperforms conventional background field removal algorithms alone in limited FOV.•Overcomes susceptibility underestimation of QSM in limited FOV.
Quantitative susceptibility mapping (QSM) is frequently employed in investigating brain iron related to brain development and diseases within deep gray matter (DGM). Nonetheless, the acquisition of whole-brain QSM data is time-intensive. An alternative approach, focusing the QSM specifically on areas of interest such as the DGM by reducing the field-of-view (FOV), can significantly decrease scan times. However, severe susceptibility value underestimations have been reported during QSM reconstruction with a limited FOV, largely attributable to artifacts from incorrect background field removal in the boundary region. This presents a considerable barrier to the clinical use of QSM with small spatial coverages using conventional methods alone.
To mitigate the propagation of these errors, we proposed a harmonic field extension method based on a physics-informed generative adversarial network. Both quantitative and qualitative results demonstrate that our method outperforms conventional methods and delivers results comparable to those obtained with full FOV. Furthermore, we demonstrate the versatility of our method by applying it to data acquired prospectively with limited FOV and to data from patients with Parkinson's disease. The method has shown significant improvements in local field results, with QSM outcomes. In a clear illustration of its feasibility and effectiveness in real clinical environments, our proposed method addresses the prevalent issue of susceptibility underestimation in QSM with small spatial coverage.
Aim
It has been proposed that platelet‐rich fibrin (PRF) can be used to support bone regeneration during alveolar ridge augmentation. The aim of this study was to determine whether an approach ...utilizing PRF provides similar performance to the established guided bone regeneration (GBR) procedure.
Materials and Methods
Two‐wall defects were surgically created in beagle dogs and treated in three experimental groups: (i) a sticky bone (SB) substitute prepared using liquid PRF and deproteinized porcine bone mineral (DPBM); (ii) SB covered with solid PRF compressed into a membrane; and (iii) GBR performed using DPBM covered by a collagen membrane. Quantitative reverse‐transcription polymerase chain reaction was applied to the specimen after 1 week of healing, and microcomputed tomography (micro‐CT) and histological outcomes were analysed after 8 weeks of healing.
Results
Compared with GBR, PRF resulted in a moderate increase in the expression levels of osteoblast and osteoclast markers, osteocalcin, and calcitonin receptor. Moreover, PRF modestly increased angiogenesis and the inflammation markers vascular endothelial growth factor (VEGF) and IL‐6. Micro‐CT and histological analyses confirmed the expected increased alveolar ridge area, with no significant differences between the three groups. Consistently, graft consolidation, as indicated by new bone formation at the defect site, did not differ significantly between groups.
Conclusions
The present results demonstrate that PRF‐based approaches perform comparably to the established GBR procedure in terms of the consolidation of DPBM in two‐wall alveolar defects.
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