Fully Integrated Microfluidic Device for Magnetic Bead Manipulation to Assist Rapid Reaction and Cleaning.

Methods to manipulate magnetic beads are essential factors to determine the efficiency and dimension of an in vitro diagnostic system. Currently, using movable permanent magnets and planar electromagnets is still the major approach to achieve magnetic bead control, causing significant constraint in the miniaturization of in vitro diagnostic systems. Here, we propose techniques to construct a fully integrated microfluidic device that can conduct automatic magnetic bead manipulation as well as rapid chemical reaction and cleaning in a minimized dimension similar to a USB disk. The device combines the precision control of multiple electromagnetic coils with the compactness of microfluidic channels, leading to one of the smallest automatic magnetic bead manipulation systems that can complete several major magnetic bead-based operation steps such as sample injection, reaction, cleaning, and collection. The influencing factors such as coil driving parameters, surface treatment of the microchannels, and properties of magnetic particles have also been investigated to optimize the device performance. The device can drive mixtures of Fe3O4 microparticles and polymer magnetic beads (PMBs) with a weight ratio of 1:1 at a maximum speed of 0.5 cm·s-1 and reduce the time for DNA binding and dissociation reactions from 20 min to only 48 s. This device has significantly advanced the conventional manipulation methods of magnetic beads and has demonstrated the possibility to construct an automatic and ultraminiaturized in vitro diagnostic system that may facilitate portable or even wearable chemical analysis.

Silver nano-reporter enables simple and ultrasensitive profiling of microRNAs on a nanoflower-like microelectrode array on glass.

MicroRNAs (miRNAs) are small non-coding RNAs with ~ 22 nucleotides, playing important roles in the post-transcriptional regulation of gene expression. The expression profiles of many miRNAs are closely related to the occurrence and progression of cancer and can be used as biomarkers for cancer diagnosis and prognosis. However, their intrinsic properties, such as short length, low abundance and high sequence homology, represent great challenges in miRNA detection of clinical samples. To overcome these challenges, we developed a simple, ultrasensitive detection platform of electrochemical miRNAs chip (e-miRchip) with a novel signal amplification strategy using silver nanoparticle reporters (AgNRs) for multiplexed, direct, electronic profiling of miRNAs. A two-step hybridization strategy was used to detect miRNAs, where the target miRNA hybridizes with a stem-loop probe to unlock the probe first, and the opened stem-loop can further hybridize with AgNRs for signaling amplification. To enhance the detection sensitivity, the gold nanoflower electrodes (GNEs) were constructed in the microaperture arrays of the e-miRchips by electroplating. With the optimal size of the GNEs, the e-miRchip showed excellent performance for miR-21 detection with a detection limit of 0.56 fM and a linear range extended from 1 fM to 10 pM. The e-miRchip also exhibited good specificity in differentiating the 3-base mismatched sequences of the target miRNA. In addition, the e-miRchip was able to directly detect miR-21 expression in the total RNA extracts or cell lysates collected from lung cancer cells and normal cells. This work demonstrated the developed e-miRchip as an efficient and promising miniaturized point-of-care diagnostic device for the early diagnosis and prognosis of cancers.

Summary of 20 tracheal intubation by anesthesiologists for patients with severe COVID-19 pneumonia: retrospective case series.

SARS-CoV-2 pandemic is announced and it is very important to share our experience to the critical care community in the early stage. Urgent intubation team was organized by anesthesiologists and was dispatched upon request. We have retrospectively reviewed medical charts of 20 critically ill patients with Covid-19 pneumonia who required tracheal intubation from February 17 to March 19 in Wuhan No.1 hospital, China. We collected their demographics, vital signs, blood gas analysis before and after tracheal intubation, and 7-day outcome after tracheal intubation. Out of 20 patients, 90% were over 60 years old and 15 were with at least one comorbidity. All meet the indication for tracheal intubation announced by treatment expert group. We had successfully intubated all patients using personal protective equipment without circulatory collapse during tracheal intubation. During the observational period, none of 17 anesthesiologists were infected. Although intubation improved SPO2, reduced PaCO2 and blood lactate, seven of 20 patients died within 7-days after tracheal intubation. Non-survivors showed significantly lower SPO2 and higher PaCO2 and blood lactate compared to survivors. For those who are anticipated to deteriorate severe pneumonia with poor prognosis, earlier respiratory support with tracheal intubation may be advised to improve outcome.

Botrysphin D attenuates arsenic-induced oxidative stress in human lung epithelial cells via activating Nrf2/ARE signaling pathways.

Oxidative stress is one of the main pathogenesis for many human diseases. Nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathway plays a key role in regulating intracellular antioxidant responses, and thus activation of Nrf2/ARE signaling pathway is a potential chemopreventive or therapeutic strategy to treat diseases caused by oxidative damage. In the present study, we have found that treatment of Beas-2B cells with botrysphins D (BD) attenuated sodium arsenite [As (III)]-induced cell death and apoptosis. Meanwhile, BD was able to upregulate protein levels of Nrf2 and its downstream genes NQO1 and γ-GCS through inducing Nrf2 nuclear translocation, enhancing protein stability, and inhibiting ubiquitination. It was also found that BD-induced activation of the Nrf2/ARE pathway was regulated by PI3K, MEK1/2, PKC, and PERK kinases. Collectively, BD is a novel activator of Nrf2/ARE pathway, and is verified to be a potential preventive agent against oxidative stress-induced damage in human lung tissues.

Discovery of natural flavonoids as activators of Nrf2-mediated defense system: Structure-activity relationship and inhibition of intracellular oxidative insults.

Continuous overproduction of reactive oxygen species (ROS), termed as oxidative stress, plays a crucial role in the onset and progression of many human diseases. Activation of nuclear transcription factor erythroid 2-related factor (Nrf2) by small molecules could eliminate ROS, and thus block the pathogenesis of oxidative stress-induced diseases. In this study, a natural flavonoid library was established and tested for their potential Nrf2 inducing effects. Based on QR inducing effect of flavonoids, their structure-activity relationship (SAR) on Nrf2 induction was summarized, and twenty flavonoids were firstly identified to be potential activators of Nrf2-mediated defensive response. Then, 7-O-methylbiochanin A (7-MBA) was further investigated for its capability on the Nrf2 activation and prevention against oxidative insults in human lung epithelial cells. Further studies indicated that 7-MBA activated Nrf2 signaling pathway and protected human lung epithelial Beas-2B cells against sodium arsenite [As(III)]-induced cytotoxicity in an Nrf2-dependent manner. Activation of Nrf2 by 7-MBA upregulated intracellular antioxidant capacity, which was produced by enhancement of Nrf2 stabilization, blockage of Nrf2 ubiquitination, as well as Nrf2 phosphorylation by mitogen-activated protein kinase (MAPK), protein kinase C (PKC), protein kinase R-like endoplasmic reticulum kinase (PERK), and phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K). Taken together, 7-MBA is a novel isoflavone-type Nrf2 activator displaying potential preventive effect against oxidative damages in human lung epithelial cells.

Catecholic Isoquinolines from Portulaca oleracea and Their Anti-inflammatory and ß2-Adrenergic Receptor Agonist Activity.

Isoquinoline alkaloids possess a wide range of structural features and pharmaceutical activities and are promising drug candidates. Ten water-soluble catecholic isoquinolines were isolated from the medicinal plant Portulaca oleracea, including three new (1-3) and seven known compounds (4-10), along with the known catecholamines 11 and 12 and four other known compounds (13-16). A method of polyamide column chromatography using EtOAc-MeOH as the mobile phase was developed for the isolation of catecholic isoquinolines. Alkaloids 1-12 exhibited anti-inflammatory activities (EC50 = 18.0-497.7 µM) through inhibition of NO production in lipopolysaccharide-induced murine macrophage RAW 264.7 cells. Among these compounds, 11, 2, 5, 4, and 8 were more potent than was the positive control, 3,4-dihydroxybenzohydroxamic acid (EC50 = 82.4 µM), with EC50 values of 18.0, 18.1, 35.4, 36.3, and 58.7 µM, respectively. Additionally, at 100 µM, compounds 1-12 showed different degrees of ß2-adrenergic receptor (ß2-AR) agonist activity in the CHO-K1/GA15 cell line which stably expressed ß2-AR as detected by a calcium assay. The EC50 values of 2 and 10 were 5.1 µM and 87.9 nM, respectively.

Screening of traditional Chinese medicines with therapeutic potential on chronic obstructive pulmonary disease through inhibiting oxidative stress and inflammatory response.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a major public health problem and gives arise to severe chronic morbidity and mortality in the world. Inflammatory response and oxidative stress play dominant roles in the pathological mechanism of COPD, and have been regarded to be two important targets for the COPD therapy. Traditional Chinese medicines (TCMs) possess satisfying curative effects on COPD under guidance of the TCM theory in China, and merit in-depth investigations as a resource of lead compounds. METHODS: One hundred ninety-six of TCMs were collected, and extracted to establish a TCM extract library, and then further evaluated for their potency on inhibitions of oxidative stress and inflammatory response using NADP(H):quinone oxidoreductase (QR) assay and nitric oxide (NO) production assay, respectively. RESULTS: Our investigation observed that 38 of the tested TCM extracts induced QR activity in hepa 1c1c7 murine hepatoma cells, and 55 of them inhibited NO production in RAW 264.7 murine macrophages at the tested concentrations. Noteworthily, 20 of TCM extracts simultaneously inhibited oxidative stress and inflammatory responses. CONCLUSION: The observed bioactive TCMs, particularly these 20 TCMs with dual inhibitory effects, might be useful for the treatment of COPD. More importantly, the results of the present research afford us an opportunity to discover new lead molecules as COPD therapeutic agents from these active TCMs.

Effects of chitosan-gentianic acid derivatives on the quality and shelf life of seabass (Lateolabrax maculatus) during refrigerated storage.

Chitosan is a natural polymer material with antibacterial, biodegradable and biocompatibility. At present, the research is mainly to enhance the antibacterial and antioxidant activity of chitosan by grafting with phenolic acids to further expand its application in food. In this study, the effect of chitosan-g-gentisic acid graft copolymer (CS-g-GA) on the shelf life of refrigerated seabass (Lateolabrax maculatus) was investigated. The results of microbial analysis demonstrated that GA and CS-g-GA treatment could effectively inhibit the growth of microorganisms. In addition, physicochemical analysis showed that GA and CS-g-GA treatment could reduce the increase of pH value, thiobarbituric acid reactive substances (TBARS), total volatile base nitrogen (TVB-N) and K-value, delay water loss, maintain texture and color, and postpone the decrease of sensory score. Compared with the control sample, CS-g-GA could keep the quality of Lateolabrax japonicus and extend its shelf-life for another 9 days. In summary, CS-g-GA has good application and development prospects for the preservation of seabass.

The Impact of Psychological Contract, Physical and Mental Health on Burnout in Grassroots Civil Servants: Evidence from China.

Introduction: The report of the 20th Party Congress proposes to build a high-quality cadre capable of taking on the important task of national rejuvenation. Grassroots civil servants are facing great pressure and challenges, and alleviating burnout has become an important issue in the construction of grassroots civil servants. Empirically analysing the impact of psychological contract on burnout of grassroots civil servants in the Chinese context will help to build a high-quality grassroots civil service team. Methods: Using a sample of 1824 grassroots civil servants in China, this study empirically examined the effect of the psychological contract on burnout among grassroots civil servants using the OLS methodology, conducted a robustness test by way of substituting variables and research methods, and then discussed the mediating effect of physical and mental health in the psychological contract and burnout among grassroots civil servants. Results: The study showed that grassroots civil servants' psychological contract had a significant negative impact on burnout; transactional psychological contract was positively related to burnout, and relational and developmental psychological contracts were negatively related to burnout in grassroots civil servants. The results of the heterogeneity analysis showed that the effect of psychological contract on burnout differed by age, gender, exercise frequency, and sleep status. The results of the mediation analysis showed that higher psychological contract scores were related to better physical and mental health, thus inhibiting burnout among grassroots civil servants. This indicates a significant mediation effect of physical and mental health in the relationship between psychological contract and burnout of grassroots civil servants. Conclusion: The psychological contract of grassroots civil servants has a significant negative effect on burnout, and physical and mental health mediate between the two. These conclusions are of great theoretical and practical significance for alleviating the stress of grassroots civil servants and improving their work performance.

Soil quality evaluation of different land use patterns on the southern and northern Qinghai-Tibet Plateau based on minimal data set.

To evaluate soil quality status of forest, grassland, and cropland in the southern and northern Tibetan Plateau, and to clarify the key influencing factors of productivity levels under three land use types, we measured the basic physical and chemical properties of 101 soil samples collected in the northern and southern Qinghai-Tibet Plateau. Principal component analysis (PCA) was used to select three indicators as the minimum data set (MDS) to comprehensively evaluate soil quality of the southern and northern Qinghai-Tibet Plateau. The result showed that soil physical and chemical properties of the three land use types were significantly different in the north and south. The contents of soil organic matter (SOM), total nitrogen (TN), available phosphorus (AP) and available potassium (AK) in the north were higher than those in the south, while the contents of SOM and TN of forest were signi-ficantly higher than those of cropland and grassland in both the north and south. Soil ammonium (NH4+-N) content showed a pattern of cropland > forest > grassland, with significant difference in the south. Soil nitrate (NO3--N) content in the north and south was the highest in the forest. Soil bulk density (BD) and electrical conductivity (EC) of cropland were significantly higher than those of grassland and forest, and that of cropland and grassland in the northern part was higher than that of southern part. Soil pH of grassland in the south was significantly higher than that of forest and cropland, and that of forest was the highest in northern part. The selected indicators for eva-luating soil quality in the north were SOM, AP, and pH, and soil quality index of forest, grassland, and cropland was 0.56, 0.53 and 0.47. The selected indicators were SOM, total phosphorus (TP), and NH4+-N in the south, and soil quality index of grassland, forest and cropland was 0.52, 0.51 and 0.48, respectively. There was a significant correlation between soil quality index obtained by the total data set and the minimum data set, and the regression coefficient was 0.69. Soil quality in the north and south of the Qinghai-Tibet Plateau were grade Ⅲ, and soil organic matter was the main indicator limiting soil quality in this area. Our results provide a scientific basis for eva-luating soil quality and ecological restoration in the Qinghai-Tibet Plateau.

A flexible omnidirectional rotating magnetic array for MRI-safe transdermal wireless energy harvesting through flexible electronics.

Magnetic resonance imaging (MRI)-safe implantable wireless energy harvester offers substantial benefits to patients suffering from brain disorders, hearing impairment, and arrhythmias. However, rigid magnets in cutting-edge systems with limited numbers of rotation axis impose high risk of device dislodgement and magnet failure. Here, a flexible omnidirectional rotating magnetic array (FORMA) and a flexible MRI-safe implantable wireless energy-harvesting system have been developed. Miniaturized flexible magnetic balls 1 millimeter in diameter achieved by molding three-dimensional printed templates can rotate freely in elastomer cavities and supply a magnetic force of 2.14 Newtons at a distance of 1 millimeter between an implantable receiver and a wearable transceiver. The system can work stably under an acceleration of 9g and obtain a power output of 15.62 decibel milliwatts at a transmission frequency of 8 megahertz. The development of the FORMA may lead to life-long flexible and batteryless implantable systems and offers the potential to promote techniques for monitoring and treating acute and chronic diseases.

A flexible wearable device coupled with injectable Fe3O4 nanoparticles for capturing circulating tumor cells and triggering their deaths.

Elimination of circulating tumor cells (CTCs) in the blood can be an effective therapeutic approach to disrupt metastasis. Here, a strategy is proposed to implement flexible wearable electronics and injectable nanomaterials to disrupt the hematogenous transport of CTCs. A flexible device containing an origami magnetic membrane is used to attract Fe3O4@Au nanoparticles (NPs) that are surface modified with specific aptamers and intravenously injected into blood vessels, forming an invisible hand and fishing line/bait configuration to specifically capture CTCs through bonding with aptamers. Thereafter, thinned flexible AlGaAs LEDs in the device offer an average fluence of 15.75 mW mm-2 at a skin penetration depth of 1.5 mm, causing a rapid rise of temperature to 48 °C in the NPs and triggering CTC death in 10 min. The flexible device has been demonstrated for intravascular isolation and enrichment of CTCs with a capture efficiency of 72.31% after 10 cycles in a simulated blood circulation system based on a prosthetic upper limb. The fusion of nanomaterials and flexible electronics reveals an emerging field that utilizes wearable and flexible stimulators to activate biological effects offered by nanomaterials, leading to improved therapeutical effects and postoperative outcomes of diseases.

In Situ Formation of Conductive Epidermal Electrodes Using a Fully Integrated Flexible System and Injectable Photocurable Ink.

In situ fabrication of wearable devices through coating approaches is a promising solution for the fast deployment of wearable devices and more adaptable devices for different sensing demands. However, heat, solvent, and mechanical sensitivity of biological tissues, along with personal compliance, pose strict requirements for coating materials and methods. To address this, a biocompatible and biodegradable light-curable conductive ink and an all-in-one flexible system that conducts in situ injection and photonic curing of the ink as well as monitoring of biophysiological information have been developed. The ink can be solidified through spontaneous phase changes and photonic cured to achieve a high mechanical strength of 7.48 MPa and an excellent electrical conductivity of 3.57 × 105 S/m. The flexible system contains elastic injection chambers embedded with specially designed optical waveguides to uniformly dissipate visible LED light throughout the chambers and rapidly cure the ink in 5 min. The resulting conductive electrodes offer intimate skin contact even with the existence of hair and work stably even under an acceleration of 8 g, leading to a robust wearable system capable of working under intense motion, heavy sweating, and varied surface morphology. Similar concepts may lead to various rapidly deployable wearable systems that offer excellent adaptability to different monitoring demands for the health tracking of large populations.

Novel compound heterozygous mutation of MLYCD in a Chinese patient with malonic aciduria.

A 3-year-old Chinese boy presented with prominent clinical features of malonic aciduria, including developmental delay, short stature, brain abnormalities and massive excretion of malonic acid and methylmalonic acid. Molecular characterization by DNA sequencing analysis and multiplex ligation-dependent probe amplification of the MLYCD gene revealed a heterozygous mutation (c.920T>G, p.Leu307Arg) in the patient and his father and a heterozygous deletion comprising exon 1 in the patient and his mother. The missense mutation (c.920T>G) was not found in 100 healthy controls and has not been reported previously. Our findings expand the number of reported cases and add a novel entry to the repertoire of MLYCD mutations.

The Impact of Internet Use on the Happiness of Chinese Civil Servants: A Mediation Analysis Based on Self-Rated Health.

With the rapid socioeconomic development of China, studies related to Internet use and civil servants' happiness have become a research hotspot in Chinese academia. This study empirically analysed the impact of Internet use on the happiness of Chinese civil servants using a sample of 3793 civil servants in Hunan Province, China. It showed that Internet use significantly enhanced the subjective well-being of Chinese civil servants. Furthermore, heterogeneity analysis revealed significant heterogeneity in the effect of the Internet on civil servants' happiness, which varied across civil service groups with different education and gender. Moreover, the effect of Internet use on the happiness of the male and better educated civil servant groups was more pronounced than in the female and less educated civil servant groups. Additionally, mediation analysis revealed that Internet use and the happiness of civil servants were not linear, with health having a significant mediating effect. This indicates that Internet use helps civil servants maintain good health, and thereby enhances the happiness of civil servants. In addition, we also use a propensity score matching model (PSM) to address the endogeneity problem due to sample selectivity bias. The results show that the estimates are more robust after eliminating sample selectivity bias. The effect of Internet use on civil servants' subjective well-being would be underestimated if the sample selectivity bias is not removed.

[Study on the chemical constituents of Phellinus lonicerinus].

OBJECTIVE: To study the chemical constituents of Phellinus lonicerinus. METHODS: The constituents were seperated and purified by silica column chromatography, Sephadex LH-20 and other column chromatography, then their structures were identified by spectral methods. RESULTS: Six compounds were isolated and identified as ergosta-6,22-dien-3beta, 5beta, 8beta-triol (1), erogosterol (2), vanillin (3), 3,4-dihydroxy benzalacetone (4), beta-sitosterol (5), docosanoic acid (6). CONCLUSION: All compounds are isolated from Phellinus lonicerinus for the first time and compound 4 isa new natural product.

Interactions between soil properties and the rhizome-root distribution in a 12-year Moso bamboo reforested region: Combining ground-penetrating radar and soil coring in the field.

Moso bamboo (Phyllostachys pubescens) plays an important role in mitigating climate change and ameliorating soil degradation because of its high carbon sequestration capacity and erosion resistance. Its strong underground rhizome-root systems form the basic framework of the aboveground system of Moso bamboo forest and define the basic ecological characteristics. However, studies on the relationship between the spatial distribution of roots and soil resources have often been neglected due to methodological limitations. The objective of this study was to test the detectability of rhizomes in the field by ground-penetrating radar (GPR) and to understand the interactions between rhizome-root systems and soil characteristics. The rhizome-root system distribution was investigated using GPR; and the soil texture, soil organic carbon and soil nutrients were investigated using a soil coring method to prepare 50-cm soil profiles. A few key findings were emphasized. First, the rhizome-root system was mainly distributed over a soil depth of 0-30 cm; and the rhizomes were larger in diameter (often greater than 1.0 cm). Therefore, GPR can accurately detect rhizomes in the field, making the non-invasive and long-term estimation of rhizome biomass and monitoring of changes in rhizome dynamics possible under field conditions. Second, the spatial heterogeneity of the soil moisture content, alkaline hydrolysed nitrogen and available phosphorus had a greater effect on the rhizomes spatial distribution than did the spatial heterogeneity of other soil characteristics. The rhizomes clonal growth led to increases in soil organic carbon, which promoted the amelioration of degraded soil. Third, the results provide insights for bamboo forest management, such as the application of GPR to prevent bamboo invasion and to determine the appropriate fertilizer level for a rhizome system. More field tests are needed to validate the application of GPR to rhizome systems and enhance the detection and quantification of rhizome systems in bamboo forest ecosystems.

Miniaturized soft centrifugal pumps with magnetic levitation for fluid handling.

Centrifugal pumps are essential mechanical components for liquid delivery in many biomedical systems whose miniaturization can promote innovative disease treatment approaches. However, centrifugal pumps are predominately constructed by rigid and bulky components. Here, we combine the soft materials and flexible electronics to achieve soft magnetic levitation micropumps (SMLMs) that are only 1.9 to 12.8 grams in weight. The SMLMs that rotate at a rotation speed of 1000 revolutions per min to pump liquids with various viscosities ranging from 1 to 6 centipoise can be used in assisting dialysis, blood circulation, and skin temperature control because of excellent biocompatibility with no organ damage. The development of SMLMs not only demonstrates the possibility to replace rigid rotating structures with soft materials for handling large volumes of fluids but also indicates the potential for fully flexible artificial organs that may revolutionize health care and improve the well-being of patients.

[Tracheal intubation in patients with severe and critical COVID-19: analysis of 18 cases].

OBJECTIVE: To analyze the clinical characteristics of patients with severe or critical coronavirus disease 2019 (COVID-19) receiving tracheal intubation. METHODS: We analyzed clinical characteristics of 18 severely or critically ill patients with COVID-19 undergoing tracheal intubation. The general demographic and clinical data of the patients including their age, gender, pre- intubation state of consciousness and the ventilation mode were recorded. The anesthesiologists performing the tracheal intubation procedure evaluated and recorded the tracheal intubation conditions of the patients. The changes in the vital signs of the patients before anesthesia induction and after intubation were recorded. RESULTS: The average ages of these patients were 70.39±8.02 years. Fifteen patients (83.33%) received non- invasive ventilation before tracheal intubation, and 13 patients (72.22%) were conscious before tracheal intubation. After induction of anesthesia, the blood pressure and heart rate of the patients decreased significantly (P < 0.05). Most of the patients (94.44%) were in excellent or good conditions for tracheal intubation, and the first-attempt success rate of tracheal intubation was 100%. Five patients died within 3 weeks following the intubation. Tracheotomy was performed in one patient. Twelve patients were still on endotracheal mechanical ventilation in the intensive care unit, and one of them received ECMO treatment due to poor oxygenation. A total of 16 experienced anesthesiologists participated in tracheal intubation, all with third-level protection during the operation, and no medical staff infection has been detected so far. CONCLUSIONS: For patients with severe and critical COVID-19 and indications of tracheal intubation, we recommend early intubation with invasive respiratory support to improve the treatment efficacy and reduce the mortality. Anesthetic agents should be used carefully during tracheal intubation to ensure patients' safety. The medical staff should have a high-level protection during the intubation to maximally ensure their safety.

Droplets as Carriers for Flexible Electronic Devices.

Coupling soft bodies and dynamic motions with multifunctional flexible electronics is challenging, but is essential in satisfying the urgent and soaring demands of fully soft and comprehensive robotic systems that can perform tasks in spite of rigorous spatial constraints. Here, the mobility and adaptability of liquid droplets with the functionality of flexible electronics, and techniques to use droplets as carriers for flexible devices are combined. The resulting active droplets (ADs) with volumes ranging from 150 to 600 µL can conduct programmable functions, such as sensing, actuation, and energy harvesting defined by the carried flexible devices and move under the excitation of gravitational force or magnetic force. They work in both dry and wet environments, and adapt to the surrounding environment through reversible shape shifting. These ADs can achieve controllable motions at a maximum velocity of 226 cm min-1 on a dry surface and 32 cm min-1 in a liquid environment. The conceptual system may eventually lead to individually addressable ADs that offer sophisticated functions for high-throughput molecule analysis, drug assessment, chemical synthesis, and information collection.