Publications by authors named "Zhichao Dong"

66 Publications

Effects of Deep Cryogenic Treatment on the Microstructure and Properties of Rolled Cu Foil.

Materials (Basel) 2021 Sep 23;14(19). Epub 2021 Sep 23.

School of Materials Science and Engineering, Shandong University of Technology, Zibo 255049, China.

The development of fifth-generation (5G) communication and wearable electronics generates higher requirements for the mechanical properties of copper foil. Higher mechanical properties and lower resistance are required for flexible copper-clad laminate and high-frequency and high-speed Cu foil. Deep cryogenic treatment (DCT), as a post-treatment method, has many advantages, such as low cost and ease of operation. However, less attention has been paid to the impact of DCT on rolled Cu foil. In this study, the effects of DCT on the microstructure and mechanical properties of rolled Cu foil were investigated. The results show that as the treatment time increased, the tensile strength and hardness first increased and then decreased, reaching a peak value of 394.06 MPa and 1.47 GPa at 12 h. The mechanical property improvement of rolled Cu foil was due to the grain refinement and the increase of dislocation density. The dislocation density of rolled Cu foil after a DCT time of 12 h was determined to have a peak value of 4.3798 × 10 m. The dislocation density increased by 19% and the grain size decreased by 12% after 12 h DCT.
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http://dx.doi.org/10.3390/ma14195498DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8509810PMC
September 2021

Lightweight Through-Hole Copper Foil as a Current Collector for Lithium-Ion Batteries.

ACS Appl Mater Interfaces 2021 Sep 24;13(35):42266-42275. Epub 2021 Aug 24.

School of Materials Science and Engineering, Shandong University of Technology, Zibo 255049, P. R. China.

In the past few decades, much effort has been dedicated to improve electrochemical performance of lithium-ion batteries (LIBs) through material design. Less attention, however, has been paid to structure engineering of battery components, which is an effective way for improving the electrochemical performance of LIBs. In this work, a lightweight Cu current collector with a through-hole array and columnar crystal on the surface (CC/THCu) was designed and fabricated using a nanosecond ultraviolet laser and electrodeposition processing to enhance specific capacity and cycle stability of LIBs. The synergistic effect of the columnar crystal and through-hole structure for improving electrochemical performances of LIBs assembled with the CC/THCu current collector was investigated. The results show that the complex structure provides spaces for volume expansion and reduces volume variation. When the hole fraction reaches 20%, the weight loss of CC/THCu is 28.41%. The corresponding LIB with the 20% hole fraction CC/THCu shows a high residual capacity rate of 81.2% and enhanced specific capacity (55.9% compared to the LIB with a bare Cu current collector). At a high rate of 1 C, the remaining specific capacity of the LIB with the CC/THCu current collector is better than that with the bare Cu current collector after 200 cycles. The CC/THCu current collector effectively improves the specific capacity and cycle stability of LIBs in contrast to the bare Cu current collector.
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http://dx.doi.org/10.1021/acsami.1c13233DOI Listing
September 2021

3D Printing a Biomimetic Bridge-Arch Solar Evaporator for Eliminating Salt Accumulation with Desalination and Agricultural Applications.

Adv Mater 2021 Aug 19;33(34):e2102443. Epub 2021 Jul 19.

Key Laboratory of Green Printing, Beijing National Laboratory for Molecular Sciences (BNLMS), Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.

Solar-driven water evaporation has been considered a sustainable method to obtain clean water through desalination. However, its further application is limited by the complicated preparation strategy, poor salt rejection, and durability. Herein, inspired by superfast water transportation of the Nepenthes alata peristome surface and continuous bridge-arch design in architecture, a biomimetic 3D bridge-arch solar evaporator is proposed to induce Marangoni flow for long-term salt rejection. The formed double-layer 3D liquid film on the evaporator is composed of a confined water film for water supplementation and a free-flowing water film with ultrafast directional Marangoni convection for salt rejection, which functions cooperatively to endow the 3D evaporator with all-in-one function including superior solar-driven water evaporation (1.64 kg m h , 91% efficiency for pure water), efficient solar desalination, and long-term salt-rejecting property (continuous 200 h in 10 wt% saline water) without any post-cleaning treatment. The design principle of the 3D structures is provided for extending the application of Marangoni-driven salt rejection and the investigation of structure-design-induced liquid film control in the solar desalination field. Furthermore, excellent mechanical and chemical stability is proved, where a self-sustainable and solar-powered desalination-cultivation platform is developed, indicating promising application for agricultural cultivation.
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http://dx.doi.org/10.1002/adma.202102443DOI Listing
August 2021

Levels of serum ecto-nucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) predicts severity of abdominal aortic calcification in end-stage renal disease patients receiving regular dialysis.

Hemodial Int 2021 Jul 7. Epub 2021 Jul 7.

Department of Nephrology, Shaoxing People's Hospital, (Shaoxing Hospital, Zhejiang University School of Medicine), Shaoxing, China.

Objective: To investigate the correlation between serum ectonucleotide pyrophosphatase/phosphodiesterase-1 (ENPP1) level and severity of abdominal vascular calcification in end-stage renal disease (ESRD) patients receiving dialysis.

Methods: A total of 124 patients were consecutively enrolled into the study in our local institution. Based on the Kidney Disease Improving Global Outcomes (KDIGO) guidelines and recommendations, abdomen lateral X-ray was used to determine abdominal aortic calcification score (AACS) for each patient at enrollment. Patients were divided into three groups based on AACS: no or mild calcification group, moderate calcification group, and severe calcification group. The relationships between ENPP1 levels and AACS were assessed by Spearman analysis and the value of ENPP1 in predicting severity of abdominal aortic calcification was evaluated by receiver operating characteristic (ROC).

Results: The level of ENPP1 in dialysis patients was (7.68 ± 1.67) ng/ml. There was no significant difference in serum ENPP1 level between peritoneal dialysis patients and hemodialysis patients (p > 0.05). The AACS of dialysis patients was negatively correlated with ENPP1 value (r = -0.70). Compared to no/mild calcification patients, the levels of serum ENPP1 in patients with moderate/severe calcification were decreased significantly (p < 0.01). The severity of vascular calcification was correlated with serum ENPP1 value, the severer the vascular calcification, the lower the serum ENPP1 level, and the difference was statistically significant (all p < 0.05). The area under ROC curve of ENPP1 was 0.90, the corresponding sensitivity was 0.86, and the specificity was 0.87.

Conclusion: Levels of serum ENPP1 in non-diabetic ESRD patients are negatively related to the severity of abdominal aortic vascular calcification.
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http://dx.doi.org/10.1111/hdi.12969DOI Listing
July 2021

Superamphiphilic TiO Composite Surface for Protein Antifouling.

Adv Mater 2021 Jun 13;33(25):e2003559. Epub 2021 May 13.

CAS Key Laboratory of Bio-Inspired Materials and Interface Sciences, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China.

Unwanted protein adsorption deteriorates fouling processes and reduces analytical device performance. Wettability plays an important role in protein adsorption by affecting interactions between proteins and surfaces. However, the principles of protein adsorption are not completely understood, and surface coatings that exhibit resistance to protein adsorption and long-term stability still need to be developed. Here, a nanostructured superamphiphilic TiO composite (TiO /SiO ) coating that can effectively prevent nonspecific protein adsorption on water/solid interfaces is reported. The confined water on the superamphiphilic surface enables a low adhesion force and the formation of an energy barrier that plays a key role in preventing protein adsorption. This adaptive design protects the capillary wall from fouling in a harsh environment during the bioanalysis of capillary electrophoresis and is further extended to applications in multifunctional microfluidics for liquid transportation. This facile approach is not only perfectly applied in channels with complicated configurations but may also offer significant insights into the design of advanced superwetting materials to control biomolecule adhesion in biomedical devices, microfluidics, and biological assays.
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http://dx.doi.org/10.1002/adma.202003559DOI Listing
June 2021

Stronger inhibitory effects of Ticagrelor plus aspirin compared with Clopidogrel plus aspirin on arachidonic acid-induced platelet aggregation in patients with acute coronary syndrome with PCI.

J Pak Med Assoc 2021 02;71(2(A)):540-542

Department of Cardiology, First Affiliated Hospital, Dalian Medical University, Dalian, China.

Antagonists of the Adenosine Diphosphate (ADP) receptor, P2Y12, may inhibit platelet aggregation as a result of stimulation with arachidonic acid (AA). The potent P2Y12 blocker, Ticagrelor has greater anti-platelet effects than Clopidogrel. We explored the effects of Ticagrelor versus Clopidogrel on mean maximum aggregation ratios (MAR%) in response to AA stimulation in patients receiving aspirin in conventional doses. A total of 613 acute coronary syndrome (ACS) patients were followed from October 2017 to October 2018. At the one- and six-month follow-up visit, mean AA-MAR% was lower in the Ticagrelor group when compared with the Clopidogrel group (28.9% vs 31.7%, 28.4% vs 31.0%, p<0.001 and p=0.001, respectively). BARC1-2 bleeding occurred with greater frequency with Ticagrelor than in patients treated with Clopidogrel (29.3% vs 9.5%, p<0.001; 23.5% vs 9.3%, p<0.001). Excessive platelet inhibition and decreased AA-MAR% were considered the main reasons for the severe subcutaneous/dermal bleeding in Ticagrelor treated patients.
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http://dx.doi.org/10.47391/JPMA.029DOI Listing
February 2021

Anomalous mechanical materials squeezing three-dimensional volume compressibility into one dimension.

Nat Commun 2020 Nov 5;11(1):5593. Epub 2020 Nov 5.

Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.

Anomalous mechanical materials, with counterintuitive stress-strain responding behaviors, have emerged as novel type of functional materials with highly enhanced performances. Here we demonstrate that the materials with coexisting negative, zero and positive linear compressibilities can squeeze three-dimensional volume compressibility into one dimension, and provide a general and effective way to precisely stabilize the transmission processes under high pressure. We propose a "corrugated-graphite-like" structural model and discover lithium metaborate (LiBO) to be the first material with such a mechanical behavior. The capability to keep the flux density stability under pressure in LiBO is at least two orders higher than that in conventional materials. Our study opens a way to the design and search of ultrastable transmission materials under extreme conditions.
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http://dx.doi.org/10.1038/s41467-020-19219-5DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7644688PMC
November 2020

Finger directed surface charges for local droplet motion.

Soft Matter 2020 Oct;16(40):9176-9182

CAS Key Laboratory of Bio-inspired Materials and Interfacial Sciences, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P. R. China. and Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beijing Advanced Innovation Centre for Biomedical Engineering, Beihang University, Beijing, 100191, P. R. China.

Water droplets are expected to be employed as animated soft matter to mimic the behaviours of both nonliving objects and small living organisms. Local water droplet motion has attracted considerable interest and has expanded into various application areas because of its close relationship with processes associated with life. However, few approaches have been capable of independently manipulating local droplet motion without loss on a substrate due to the difficulty in shaping and focusing the motion route. Here, we demonstrate a non-contact electrostatic-powered local water motion strategy. The gradient of electrostatic charges in space guides the local drop motion without liquid loss in a controlled motion path. The local droplet motion on surfaces with varied wettabilities is discussed and compared. A unipolar electrostatic field is theoretically simulated. This work can introduce a finger-directed surface charge pattern and local droplet motion as a new variable in many droplet robot schemes and inspire next-generation liquid devices.
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http://dx.doi.org/10.1039/d0sm01073aDOI Listing
October 2020

Continuous 3D printing from one single droplet.

Nat Commun 2020 Sep 17;11(1):4685. Epub 2020 Sep 17.

Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun North First Street 2, 100190, Beijing, P.R. China.

3D printing has become one of the most promising methods to construct delicate 3D structures. However, precision and material utilization efficiency are limited. Here, we propose a one-droplet 3D printing strategy to fabricate controllable 3D structures from a single droplet ascribing to the receding property of the three-phase contact line (TCL) of the resin droplet. The well-controlled dewetting force of liquid resin on the cured structure results in the minimization of liquid residue and the high wet and net material utilization efficiency in forming a droplet into a 3D structure. Additionally, extra curing induced protruding or stepped sidewalls under high printing speed, which require high UV intensity, can be prevented. The critical is the free contact surface property of the droplet system with the introduction of the receding TCL, which increased the inner droplet liquid circulation and reduces the adhesion properties among the liquid resin, cured resin, and resin vat.
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http://dx.doi.org/10.1038/s41467-020-18518-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7499235PMC
September 2020

Directional liquid dynamics of interfaces with superwettability.

Sci Adv 2020 Sep 9;6(37). Epub 2020 Sep 9.

CAS Key Laboratory of Bio-inspired Materials and Interface Sciences, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China.

Natural creatures use their surface structures to control directional liquid dynamics for survival. Learning from nature, artificial superwetting materials have triggered technological revolutions in many disciplines. To improve controllability, researchers have attempted to use external fields, such as thermal, light, magnetic, and electric fields, to assist or achieve controllable liquid dynamics. Emerging directional liquid transport applications have prosperously advanced in recent years but still present some challenges. This review discusses and summarizes the field of directional liquid dynamics on natural creatures and artificial surfaces with superwettabilities and ventures to propose several potential strategies to construct directional liquid transport systems for fog collection, 3D printing, energy devices, separation, soft machine, and sensor devices, which are useful for driving liquid transport or motility.
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http://dx.doi.org/10.1126/sciadv.abb5528DOI Listing
September 2020

Liquid harvesting and transport on multiscaled curvatures.

Proc Natl Acad Sci U S A 2020 09 8;117(38):23436-23442. Epub 2020 Sep 8.

Chinese Academy of Sciences Key Laboratory of Bio-inspired Materials and Interface Sciences, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190 Beijing, China.

Various creatures, such as spider silk and cacti, have harnessed their surface structures to collect fog for survival. These surfaces typically stay dry and have a large contact hysteresis enabling them to move a condensed water droplet, resulting in an intermittent transport state and a relatively reduced speed. In contrast to these creatures, here we demonstrate that offers a remarkably integrated system on its peristome surface to harvest water continuously in a humid environment. Multicurvature structures are equipped on the peristome to collect and transport water continuously in three steps: nucleation of droplets on the ratchet teeth, self-pumping of water collection that steadily increases by the concavity, and transport of the acquired water to overflow the whole arch channel of the peristome. The water-wetted peristome surface can further enhance the water transport speed by ∼300 times. The biomimetic design expands the application fields in water and organic fogs gathering to the evaporation tower, laboratory, kitchen, and chemical industry.
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http://dx.doi.org/10.1073/pnas.2011935117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7519342PMC
September 2020

18-Year Follow-Up After Coronary Stenting for Left Main Coronary Artery Lesions.

Int Heart J 2020 Sep 2;61(5):1041-1043. Epub 2020 Sep 2.

Department of Cardiology, First Affiliated Hospital, Dalian Medical University.

The current treatment of radiation-induced coronary artery disease (RCAD) is comparable to that of generic coronary artery disease (CAD); however, the outcomes of these treatment measures have not been fully examined in RCAD. A 33-year-old woman, without conventional cardiovascular risk factors, presented with left main coronary artery (LMCA) lesions. At the age of 26, she received mediastinal radiation therapy (RT) to treat mixed cellularity Hodgkin lymphoma. One BiodivYsio 3.5 × 18 mm stent was implanted at the LMCA site. At the age of 38, the patient was treated by balloon dilatation because of approximately 50% in-stent stenosis. At the last follow-up in February 2018, when the patient was 51 years old, she no longer complained of chest pain. Coronary angiography showed no de novo or in-stenosis lesions, although optical coherence tomography showed mild neointimal proliferation, calcific plaque, small ruptured intima, and several uncovered struts. The experience of treating this case may shed some light on coronary stenting in coronary lesions caused by RCAD.
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http://dx.doi.org/10.1536/ihj.20-064DOI Listing
September 2020

Detection and closed-loop control of piston errors for a Fizeau imaging interferometer.

Appl Opt 2020 May;59(13):3892-3900

In the Fizeau imaging interferometer testbed we recently built, the optical path difference (OPD; i.e., piston error) among three sub-telescopes should be corrected for phased imaging to enhance the spatial resolution. This study presents the detection of the OPD via a dispersed fringe sensor (DFS) method and its closed-loop control. The retrieval of the OPD from a dispersed fringe map is a fast-Fourier-transform-based DFS method, which indicates in theory that the OPD has a linear relationship with the displacement of the secondary peaks in the Fourier spectrum of the dispersed fringe map. Then the design and alignment of the OPD detection module are presented, as well as the OPD compensation module with a two-level motion stage. A unique benefit of the fast-Fourier-transform-based DFS is high time efficiency for closed-loop control; for a window of $32 \times 128 \;{\rm pixels}$32×128pixels, a 932 Hz computation rate was achieved by dedicated electrical hardware, which is significant for the distributed satellite formation-flying platform. The experiments validated (1) that the detection range of the DFS is more than $\pm {160}\;\unicode{x00B5}{\rm m}$±160µm, (2) that the OPD has a fine-line relationship with the secondary peak displacement, (3) the feasibility of the DFS method used for closed-loop control, and (4) that an OPD control precision of 0.0593 µm RMS is achieved.
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http://dx.doi.org/10.1364/AO.387895DOI Listing
May 2020

Highly efficient three-dimensional solar evaporator for high salinity desalination by localized crystallization.

Nat Commun 2020 Jan 27;11(1):521. Epub 2020 Jan 27.

Key Laboratory of Green Printing, Institute of Chemistry, Chinese Academy of Sciences, Zhongguancun North First Street 2, Beijing, 100190, PR China.

Solar-driven water evaporation represents an environmentally benign method of water purification/desalination. However, the efficiency is limited by increased salt concentration and accumulation. Here, we propose an energy reutilizing strategy based on a bio-mimetic 3D structure. The spontaneously formed water film, with thickness inhomogeneity and temperature gradient, fully utilizes the input energy through Marangoni effect and results in localized salt crystallization. Solar-driven water evaporation rate of 2.63 kg m h, with energy efficiency of >96% under one sun illumination and under high salinity (25 wt% NaCl), and water collecting rate of 1.72 kg m h are achieved in purifying natural seawater in a closed system. The crystalized salt freely stands on the 3D evaporator and can be easily removed. Additionally, energy efficiency and water evaporation are not influenced by salt accumulation thanks to an expanded water film inside the salt, indicating the potential for sustainable and practical applications.
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http://dx.doi.org/10.1038/s41467-020-14366-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6985111PMC
January 2020

Bioinspired Smart Liquid Directional Transport Control.

Langmuir 2020 01 15;36(3):667-681. Epub 2020 Jan 15.

CAS Key Laboratory of Bio-inspired Materials and Interfacial Sciences, Technical Institute of Physics and Chemistry , Chinese Academy of Sciences , Beijing 100190 , China.

Developments in bioinspired superwetting materials have triggered technological revolutions in many disciplines. One representative area is liquid directional transport dominated by interface properties, which has experienced rapid progress recently. To improve the controllability, scientists try to use the external field, such as light, electricity, thermal, and so on, to assist or achieve controllable smart, responsive liquid directional transport. However, there are still some intractable problems and challenges behind prosperity. Here, we summarize the relevant basic theory of surface wettability and the processes of the development of bioinspired superwetting materials. We discuss the different essential mechanisms of liquid directional transport. Furthermore, smart external field-controlled fluid directional transport is the primary focus of this feature article. We briefly put forward our views on some outstanding problems, existing challenges, and trends in this field.
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http://dx.doi.org/10.1021/acs.langmuir.9b03385DOI Listing
January 2020

Apex structures enhance water drainage on leaves.

Proc Natl Acad Sci U S A 2020 01 14;117(4):1890-1894. Epub 2020 Jan 14.

Chinese Academy of Sciences Key Laboratory of Bio-inspired Materials and Interfacial Sciences, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190 Beijing, China;

The rapid removal of rain droplets at the leaf apex is critical for leaves to avoid damage under rainfall conditions, but the general water drainage principle remains unclear. We demonstrate that the apex structure enhances water drainage on the leaf by employing a curvature-controlled mechanism that is based on shaping a balance between reduced capillarity and enhanced gravity components. The leaf apex shape changes from round to triangle to acuminate, and the leaf surface changes from flat to bent, resulting in the increase of the water drainage rate, high-dripping frequencies, and the reduction of retention volumes. For wet tropical plants, such as , Gaussian curvature reconfiguration at the drip tip leads to the capillarity transition from resistance to actuation, further enhancing water drainage to the largest degree possible. The phenomenon is distinct from the widely researched liquid motion control mechanisms, and it offers a specific parametric approach that can be applied to achieve the desired fluidic behavior in a well-controlled way.
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http://dx.doi.org/10.1073/pnas.1909924117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6995007PMC
January 2020

Ricocheting Droplets Moving on Super-Repellent Surfaces.

Adv Sci (Weinh) 2019 Nov 12;6(21):1901846. Epub 2019 Sep 12.

ARC Centre of Excellence in Convergent Bio-Nano Science and Technology, and the Department of Chemical Engineering The University of Melbourne Parkville Victoria 3010 Australia.

Droplet bouncing on repellent solid surfaces (e.g., the lotus leaf effect) is a common phenomenon that has aroused interest in various fields. However, the scenario of a droplet bouncing off another droplet (either identical or distinct chemical composition) while moving on a solid material (i.e., ricocheting droplets, droplet billiards) is scarcely investigated, despite it having fundamental implications in applications including self-cleaning, fluid transport, and heat and mass transfer. Here, the dynamics of bouncing collisions between liquid droplets are investigated using a friction-free platform that ensures ultrahigh locomotion for a wide range of probing liquids. A general prediction on bouncing droplet-droplet contact time is elucidated and bouncing droplet-droplet collision is demonstrated to be an extreme case of droplet bouncing on surfaces. Moreover, the maximum deformation and contact time are highly dependent on the position where the collision occurs (i.e., head-on or off-center collisions), which can now be predicted using parameters (i.e., effective velocity, effective diameter) through the concept of an effective interaction region. The results have potential applications in fields ranging from microfluidics to repellent coatings.
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http://dx.doi.org/10.1002/advs.201901846DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6839626PMC
November 2019

Bioinspired Tip-Guidance Liquid Jetting and Droplet Emission at a Rotary Disk a Surface Energy Gradient.

ACS Nano 2019 11 8;13(11):13100-13108. Epub 2019 Nov 8.

CAS Key Laboratory of Bio-inspired Materials and Interfacial Sciences , Technical Institute of Physics and Chemistry, Chinese Academy of Sciences , Beijing 100190 , China.

Effective droplet emission is of fundamental importance for practical application, such as agricultural sprays to painting, atomization, emulsification, and catalytic action. Highly viscous liquids are commonly used, such as printing inks, which hinder the ejection at the nozzle. A big challenge faced by people is how to obtain stable and controllable liquid droplets in a wide range of viscosities. Inspired by the rotation shaking of droplets on fiber clusters and the rotary spraying disk technique, here, we demonstrate uniform microdroplet (1-2000 mPa·s) generation in a tip-guided way that replaces the commonly confined nozzle by a double-layer spinning "sandwich" multitip disk (SSMD). A surface energy gradient induced by the margin structure of the alternating gas wedge and solid tip guides liquid to move along the solid tip, which is ejected at the end of the tip, forming a ring of droplet clusters. SSMD improves the effective droplet-jet process to 7/10 of the whole drainage process and enhances the efficiency with a production drop volume of ∼3.19 × 10 μL/h and production droplet numbers of ∼3.3 × 10 per second. Droplets can be fine-tuned between 0.1 and 1.0 mm the tip structure, liquid property, and spinning angular velocity with a narrow size distribution. This facile tip-guided design could inspire the possibility of energy-efficient droplet production techniques in various fluid applications, such as spraying and printing. It may further improve other fluid systems that serve as a crucial component for high-speed droplet manipulation, liquid transport, and water vapor capturing.
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http://dx.doi.org/10.1021/acsnano.9b05860DOI Listing
November 2019

Developing on-machine 3D profile measurement for deterministic fabrication of aspheric mirrors: erratum.

Appl Opt 2019 10;58(28):7844

This erratum adds a reference to the published paper, Appl. Opt.53, 4997 (2014)APOPAI0003-693510.1364/AO.53.004997.
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http://dx.doi.org/10.1364/AO.58.007844DOI Listing
October 2019

Controllable High-Speed Electrostatic Manipulation of Water Droplets on a Superhydrophobic Surface.

Adv Mater 2019 Oct 13;31(43):e1905449. Epub 2019 Sep 13.

School of Future Technology, University of Chinese Academy of Sciences, Beijing, 100049, P. R. China.

Biological processes and technological applications cannot work without liquid control, where versatile water droplet manipulation is a significant issue. Droplet motion is conventionally manipulated by functionalizing the target surface or by utilizing additives in the droplet, still, with uncontrolled limitation on superhydrophobic surfaces since droplets are either unable to move fast or are difficult to stop while moving. A controllable high-speed "all-in-one" no-loss droplet manipulation, that is, in-plane moving and stopping/pinning in any direction on a superhydrophobic surface, with electrostatic charging is demonstrated. The experimental results reveal that the transport speed can vary from zero to several hundreds of millimeters per second. Controlled dynamic switching between the onset moving state and the offset pinning state of a water droplet can be achieved by out-of-plane electrostatic charging. This work opens the possibility of droplet control techniques in various applications, such as combinatory chemistry, biochemical, and medical detection.
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http://dx.doi.org/10.1002/adma.201905449DOI Listing
October 2019

Uniform Spread of High-Speed Drops on Superhydrophobic Surface by Live-Oligomeric Surfactant Jamming.

Adv Mater 2019 Oct 29;31(41):e1904475. Epub 2019 Aug 29.

School of Chemical Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China.

Inkjet printing of water-based inks on superhydrophobic surfaces is important in high-resolution bioarray detection, chemical analysis, and high-performance electronic circuits and devices. Obtaining uniform spreading of a drop on a superhydrophobic surface is still a challenge. Uniform round drop spreading and high-resolution inkjet printing patterns are demonstrated on superhydrophobic surfaces without splash or rebound after high-speed impacting by introducing live-oligomeric surfactant adhesion. During impact, the live-oligomeric surfactant molecules aggregate into dynamic, wormlike micelle networks, which jam at the solid-liquid interface by entangling with the surface micro/nanostructures to pin the contact line and jam at the spreading periphery to keep the uniform spreading lamellar shape. This efficient uniform spreading of high-speed impact drops opens a promising avenue to control drop impact dynamics and achieve high-resolution printing.
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http://dx.doi.org/10.1002/adma.201904475DOI Listing
October 2019

Enhancing Droplet Deposition on Wired and Curved Superhydrophobic Leaves.

ACS Nano 2019 Jul 3;13(7):7966-7974. Epub 2019 Jul 3.

CAS Key Laboratory of Bio-inspired Materials and Interfacial Science, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences Future Technology College , University of Chinese Academy of Sciences, Chinese Academy of Sciences , Beijing 100190 , P.R. China.

Droplet deposition on superhydrophobic surfaces has been a great challenge owing to the shortness of the impact contact time. Despite recent research progress regarding flat superhydrophobic surfaces, improving deposition on ubiquitous wired and curved superhydrophobic leaves remains challenging as their surface structures promote asymmetric impacts, thereby shortening the contact times and increasing the likelihood of droplet splitting. Here, we propose a strategy to solve the deposition problems based on an analysis of the impact dynamics and a rational selection of additives. Combining the prominent extension property of flexible polymers with surface tension reduction of the surfactant, the well-chosen binary additives cooperatively solve retention and coverage problems by limiting the fragment and enhancing local pinning and wetting processes at a very low usage. This work advances the understanding of droplet deposition by rationally selecting additives based on the impact dynamics, which is believed to be useful in a variety of spraying, coating, and printing applications.
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http://dx.doi.org/10.1021/acsnano.9b02457DOI Listing
July 2019

Bioinspired inner microstructured tube controlled capillary rise.

Proc Natl Acad Sci U S A 2019 06 10;116(26):12704-12709. Epub 2019 Jun 10.

Chinese Academy of Sciences Key Laboratory of Bio-inspired Materials and Interfacial Sciences, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, 100190 Beijing, China.

Effective, long-range, and self-propelled water elevation and transport are important in industrial, medical, and agricultural applications. Although research has grown rapidly, existing methods for water film elevation are still limited. Scaling up for practical applications in an energy-efficient way remains a challenge. Inspired by the continuous water cross-boundary transport on the peristome surface of , here we demonstrate the use of peristome-mimetic structures for controlled water elevation by bending biomimetic plates into tubes. The fabricated structures have unique advantages beyond those of natural pitcher plants: bulk water diode transport behavior is achieved with a high-speed passing state (several centimeters per second on a milliliter scale) and a gating state as a result of the synergistic effect between peristome-mimetic structures and tube curvature without external energy input. Significantly, on further bending the peristome-mimetic tube into a "candy cane"-shaped pipe, a self-siphon with liquid diode behavior is achieved. Such a transport mechanism should inspire the design of next generation water transport devices.
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http://dx.doi.org/10.1073/pnas.1821493116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6600971PMC
June 2019

Ground-testing method of a zero gravity wavefront for space telescopes.

Appl Opt 2019 Apr;58(12):3042-3052

A ground-testing method and an algorithm are presented to demonstrate how to predict the image quality for an orbiting space telescope under 0 g. By using a mathematical model of the ground-testing system, one has to change the gravity conditions to get a 0 g wavefront. For the Hinode space telescope, one can change the gravity acceleration from +1  g to -1  g by rotating the telescope upside down, which is difficult for larger optical space telescopes. In this paper we introduce a new algorithm to get 0 g results by measuring the wavefronts under different gravity acceleration sets. In this way we can predict the 0 g image quality under any gravity acceleration value. With the algorithm, we propose to use oscillation in the vertical direction to mimic the change of the telescope figure under acceleration caused by gravity. Criteria of tests and estimates of errors are discussed in this paper. A test experiment is designed and performed for a scaled model of the space solar telescope (SST). The optical test system includes a 1.4-mm-thick, 101.6-mm-diameter flat mirror, and has almost the same gravity sag as the SST's 1-m-diameter primary has; thus, it can be compared to the Hinode method. As a suspending spring mass oscillation system, it provides a gravity environment varying sinusoidally around 1 g. Gravity accelerations and response wavefronts are aligned in time. Test results and comparisons to Hinode's are achieved and listed. The differences between our method and Hinode's results is less than 1/20λ RMS, which is sufficient for testing a diffraction limited space optical system.
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http://dx.doi.org/10.1364/AO.58.003042DOI Listing
April 2019

Design and experimental demonstration of pointing correction module for a Fizeau imaging interferometer.

Appl Opt 2018 Dec;57(34):9936-9943

To increase the spatial resolution while circumventing the problems of increased mass and volume of monolithic telescopes, a Fizeau imaging interferometer testbed (FIIT) with three individual subtelescopes was designed and constructed for high resolution astronomical observation. FIIT is intended to be mounted on a distributed small-satellite constellation with a formation fly configuration; thus the extremely stable pointing of the subtelescopes is the prerequisite for phased imaging, which is because the satellite suffers from some extent of detrimental jitters and drifts needs to be corrected by FIIT itself. FIIT makes use of a shared tip/tilt detection module with a cross-correlation algorithm, three fast-steering mirrors, and closed-loop control technology for pointing correction of three subtelescopes, which can make sure the images are coaligned for a long period of time used to image some faint astronomical objects. This study gives a detailed description of the detection algorithm of image shifts, the hardware design, and data processing flow, followed by closed-loop experiments of a wide-band white light point source. The results of residual errors on the detection camera and the beam-combining camera demonstrate the performance of the pointing correction function, which is a significant milestone for FIIT.
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http://dx.doi.org/10.1364/AO.57.009936DOI Listing
December 2018

Effect of Hatch Spacing on Melt Pool and As-built Quality During Selective Laser Melting of Stainless Steel: Modeling and Experimental Approaches.

Materials (Basel) 2018 Dec 24;12(1). Epub 2018 Dec 24.

Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing 100081, China.

In this study, a combined simulation and experimental approach is utilized to investigate the influence of hatch spacing on the microstructure and as-built quality of 316L stainless steel (SS) samples fabricated by selective laser melting (SLM). A three-dimensional finite element model (FEM) is employed to investigate heat transfer and melt pool during the SLM of 316L SS. The phase transformation and variation of the thermo-physical properties of the materials are considered in this model. The effects of hatch spacing (H) on the temperature field, microstructure and melt pool size, overlap rate, surface quality, and relative density during the SLM of 316L SS are investigated. The simulated results indicate that, as the hatch spacing increases, the depth increases and the width of the melt pool decreases. Meanwhile, with the increase of hatch spacing, the simulated temperature of the subsequent tracks falls below the melting temperature of the first track. Moreover, the microstructures were found to coarsen with the increasing hatch spacing due to the reduced cooling rate. The optimized hatch spacing and overlap rate between adjacent tracks were obtained from numerical simulations. Simulation results illustrate that, when the optimized hatch spacing of 100 μm is adopted, fully dense parts with a smooth surface can be fabricated by SLM, thus experimentally validating the simulation results.
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http://dx.doi.org/10.3390/ma12010050DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6337478PMC
December 2018

Study of Size Effect on Microstructure and Mechanical Properties of AlSi10Mg Samples Made by Selective Laser Melting.

Materials (Basel) 2018 Dec 4;11(12). Epub 2018 Dec 4.

Institute of Advanced Structure Technology, Beijing Institute of Technology, Beijing 100081, China.

The macroscopic mechanical performance of additive manufactured structures is essential for the design and application of multiscale microlattice structure. Performance is affected by microstructure and geometrical imperfection, which are strongly influenced by the size of the struts in selective laser melting (SLM) lattice structures. In this paper, the effect of size on microstructure, geometrical imperfection, and mechanical properties was systemically studied by conducting experimental tests. A series of AlSi10Mg rod-shaped samples with various diameters were fabricated using SLM. The uniaxial tensile test results show that with the decrease in build diameter, strength and Young's modulus of strut decreased by 30% more than the stable state. The main reasons for this degradation were investigated through microscopic observation and micro X-ray computed tomography (μ-CT). In contrast with large-sized strut, the inherent porosity (1.87%) and section geometrical deviation (3%) of ponysize strut is greater because of the effect of thermal transform and hydrogen evolution, and the grain size is 0.5 μm. The discrepancy in microstructure, geometrical imperfection, and mechanical properties induced by size effect should be considered for the design and evaluation of SLM-fabricated complex structures.
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http://dx.doi.org/10.3390/ma11122463DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6316933PMC
December 2018

Space-qualified fast steering mirror for an image stabilization system of space astronomical telescopes.

Appl Opt 2018 Nov;57(31):9307-9315

A space-qualified fast steering mirror (SQ-FSM) was designed, built, and tested at the National Astronomical Observatories of the Chinese Academy of Sciences for an image stabilization system of space astronomical telescopes, which is used for the tip-tilt correction of small jitter of the satellite platform; this achieved image stability in a closed-loop manner. Its design primarily faces four challenges involving (1) sustaining the specified sine and random vibration without launch lock, as well as shock response spectrum experiments; (2) surface form error of a clear aperture of ϕ120  mm less than 1/50λ root mean square (RMS, λ=632.8  nm) with a relatively rigid mirror support; (3) resonance frequency of at least 800 Hz and as high as possible; (4) minimum reaction force and torque in order to decrease its unfavorable influence on the satellite platform. To achieve these goals, the global optimizations and compromises have to be made throughout the design process. The study reviews the detailed design of the SQ-FSM with respect to the four challenges, mainly by keeping the mirror and its support lightweight, mirror bonding and solidification, actuator and its stiffness, flexure support of the mirror and its holder, material optimization for weight, stiffness, and coefficient of thermal expansion, as well as finite element analysis on statics and dynamics. The performances are also measured and expatiated, including the surface form, resonant frequency, tip-tilt stroke, vibration and shock response spectrum experiments, etc., which validate the performances of the SQ-FSM.
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http://dx.doi.org/10.1364/AO.57.009307DOI Listing
November 2018

Drop Cargo Transfer via Unidirectional Lubricant Spreading on Peristome-Mimetic Surface.

ACS Nano 2018 Nov 18;12(11):11307-11315. Epub 2018 Oct 18.

Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beijing Advanced Innovation Center for Biomedical Engineering , Beihang University , Beijing 100191 , P. R. China.

To promote drop mobility, lubricating the gap between liquid drop and solid surface is a facile method which has been widely exploited by nature. Examples include lotus and rice leaves using entrapped air to "lubricate" water and Nepenthes pitcher plant using a slippery water layer to trap insects. Inspired by these, here, we report a strategy for transporting drop cargoes via the unidirectional spreading of immiscible lubricants on the peristome-mimetic surface. Oleophilic/hydrophobic peristome-mimetic surfaces were fabricated through replicating three-dimensional printed samples. The peristome-mimetic surface, via unidirectional immiscible hexadecane spreading, can transport a wide diversity of drop cargoes over a long distance with no loss with controllable drop volumes and velocities, hence mixing multiphase liquids and even reacting liquids. We anticipate this unidirectional drop cargo transport technique will find use in microfluidics, microreactors, water harvesting systems, etc.
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http://dx.doi.org/10.1021/acsnano.8b06023DOI Listing
November 2018

Dual-Programmable Shape-Morphing and Self-Healing Organohydrogels Through Orthogonal Supramolecular Heteronetworks.

Adv Mater 2018 Dec 17;30(51):e1804435. Epub 2018 Oct 17.

Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, Beijing, 100191, P. R. China.

Programmable materials that can change their inherent shapes or properties are highly desirable due to their promising applications. However, among various programmable shape-morphing materials, the single control route allows temporary states to recover the unchangeable former state, thus lacking the sophisticated programmability for their shape-encoding behaviors and mechanics. Herein, dual-programmable shape-morphing organohydrogels featuring supramolecular heteronetworks are developed. In the system, the metallo-supramolecular hydrogel framework and micro-organogels featuring semicrystalline comb-type networks independently respond to different stimuli, thereby providing orthogonal dual-switching mechanics and ultrahigh mechanical strength. The supramolecular heteronetworks also possess excellent self-healing properties. More notably, such orthogonal supramolecular heteronetworks demonstrate hierarchical shape morphing performance that far exceeds conventional shape-morphing materials. Utilizing this dual programming strategy of the orthogonal supramolecular heteronetworks, the material's permanent shape can be manipulated in a step-wise shape morphing process, thereby realizing sophisticated shape changes with a high degree of freedom. The organohydrogels can act as a biomimetic smart device for the on-demand control of unidirectional liquid transport. Based on these characteristics, it is anticipated that the supramolecular organohydrogels may serve as adaptive programmable materials for a variety of applications.
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http://dx.doi.org/10.1002/adma.201804435DOI Listing
December 2018
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