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An Automatic Implementation of Oropharyngeal Swab Sampling for Diagnosing Respiratory Infectious Diseases via Soft Robotic End-Effectors

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Chinese Journal of Mechanical Engineering 2024年第2期37卷 55-67页

作者： Yafeng Cui Wenjie Yu Jingjing Li Qi Shao Ding Weng Guoping Yin Xiaohao Zhang Xinjun Liu Jingying Ye jiadao wang Huichan Zhao Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Beijing Huakang Tongbang Technology Company Beijing 102609China Department of Otorhinolaryngology Beijing Tsinghua Changgung HospitalSchool of Clinical MedicineTsinghua UniversityBeijing 102218China Tianjin Research Institute for Advanced Equipment Tsinghua UniversityTianjin 300300China

The most widely adopted method for diagnosing respiratory infectious diseases is to conduct polymerase chain reaction(PCR)assays on patients’respiratory specimens,which are collected through either nasal or oropharyngeal *** manual swab sampling process poses a high risk to the examiner and may cause false-negative results owing to improper *** this paper,we propose a pneumatically actuated soft end-effector specifically designed to achieve all of the tasks involved in swab *** soft end-effector utilizes circumferential instability to ensure grasping stability,and exhibits several key properties,including high load-to-weight ratio,error tolerance,and variable swab-tip stiffness,leading to successful automatic robotic oropharyngeal swab sampling,from loosening and tightening the transport medium tube cap,holding the swab,and conducting sampling,to snapping off the swab tail and sterilizing *** an industrial collaborative robotic arm,we integrated the soft end-effector,force sensor,camera,lights,and remote-control stick,and developed a robotic oropharyngeal swab sampling *** this swab sampling system,we conducted oropharyngeal swab-sampling tests on 20 *** Digital PCR assay results(RNase P RNA gene absolute copy numbers for the samples)revealed that our system successfully collected sufficient numbers of cells from the pharyngeal wall for respiratory disease *** summary,we have developed a pharyngeal swab-sampling system based on an“enveloping”soft actuator,studied the sampling process,and imple-mented whole-process robotic oropharyngeal swab-sampling.

关键词： Diagnosis Medical robot Soft end-effector Swab-sampling Digital PCR

Bionic Research on Fish Scales for Drag Reduction

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Journal of Bionic Engineering 2012年第4期9卷 457-464页

作者： Zhaoliang Dou jiadao wang Darong Chen State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084P.R.China

To reduce friction drag with bionic method in a more feasible way, the surface microstructure of fish scales was analyzed attempting to reveal the biologic features responding to skin friction drag reduction. Then comparable bionic surface mimicking fish scales was fabricated through coating technology for drag reduction. The paint mixture was coated on a substrate through a self-developed spray-painting apparatus. The bionic surface with micron-scale caves formed spontaneously due to the interra- cial convection and deformation driven by interfacial tension gradient in the presence of solvent evaporation. Comparative experiments between bionic surface and smooth surface were performed in a water tunnel to evaluate the effect of bionic surface on drag reduction, and visible drag reduction efficiency was obtained. Numerical simulation results show that gas phase de- velops in solid-liquid interface of bionic surface with the effect of surface topography and partially replaces the solid-liquid shear force with gas-liquid shear force, hence reducing the skin friction drag effectively. Therefore, with remarkable drag re- duction performance and simple fabrication technology, the proposed drag reduction technique shows the promise for practical applications.

关键词： drag reduction micro-structured bionic surface fish scales polymer coating interfacial convection and deformation

A prediction of drag reduction by entrapped gases in hydrophobic transverse grooves

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Science China(Technological Sciences) 2013年第12期56卷 2973-2978页

作者： wang Bao wang jiadao CHEN DaRong State Key Laboratory of Tribology Tsinghua University

The drag reduction effect of super-hydrophobic surface induced by the entrapped gas is unstable due to the gradual disappearance of the trapped *** this paper,a hydrophobic transverse grooved surface was designed to sustain gas in valleys.A detail numerical simulation was presented to investigate the flow field near the proposed *** water flowed over this surface,the entrapped gas was blocked by the ridges and the solid-liquid interface was replaced by the liquid-gas interface due to the entrapped gas,furthermore the micro-vortex formed in the *** there was an effective slippage between water and solid induced by the entrapped gas,the velocity gradient of boundary layer decreased,which contributed to a remarkable drag reduction ***,considering the extra undesired pressure drag reduction which negatively impacted the drag reduction effect of this method,the total drag coefficient including the viscous drag coefficient and the pressure coefficient was *** effective drag reduction rate of about 15%was achieved and the effect of this method was confirmed by experiments conducted in a high-speed water tunnel when grooves were optimized.

关键词： hydrophobic transverse groove gas skin-friction drag reduction computational fluid dynamics(CFD)

Synthesis of Biomimetic Superhydrophobic Surface through Electrochemical Deposition on Porous Alumina

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Journal of Bionic Engineering 2011年第2期8卷 122-128页

作者： jiadao wang Ang Li Haosheng Chen Darong Chen State Key Laboratory of Tribology Tsinghua University Beijing 100084 P. R. China

The superhydrophobicity of plant leaves is a benefit of the hierarchical structures of their surfaces. These structures have been imitated in the creation of synthetic surfaces. In this paper, a novel process for fabrication of biomimetic hierarchical structures by electrochemical deposition of a metal on porous alumina is described. An aluminum specimen was anodically oxidized to obtain a porous alumina template, which was used as an electrode to fabricate a surface with micro structures through electrochemical deposition of a metal such as nickel and copper after the enlargement of pores. Astonishingly, a hier- archical structure with nanometer pillars and micrometer clusters was synthesized in the pores of the template. The nanometer pillars were determined by the nanometer pores. The lbrmation of micrometer clusters was related to the thin walls of the pores and the crystallization of the metal on a flat surface. From the as-prepared biomimetic surfaces, lotus-leaf-like superhydrophobic surfaces with nickel and copper deposition were achieved.

关键词： porous alumina electrochemical deposition anodization superhydrophobic surface bioinspired hierarchical structure

Underwater drag reduction by gas

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Friction 2014年第4期2卷 295-309页

作者： jiadao wang Bao wang Darong CHEN State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China

Publications on underwater drag reduction by gas have been gathered in the present *** methods,results and conclusions from the publications have been discussed and *** stable existence of gas is a requirement for underwater drag reduction induced by slippage at the water-solid interface.A superhydrophobic surface can entrap gas in surface structures at the water-solid ***,many experimental results have exhibited that the entrapped gas can disappear,and the drag gradually increases until the loss of drag reduction with immersion time and underwater *** some other surface structures were also experimented to hold the entrapped gas,from the analysis of thermodynamics and mechanics,it is difficult to prohibit the removal of entrapped gas in underwater surface ***,it is essential to replenish a new gas supply for continued presence of gas at the interface for continued underwater drag *** gas supplement is an effective method for underwater drag reduction,however,that needs some specific equipment and additional energy to generate gas,which limits its practical *** or supercavitation is a method for passive gas generation,but it is only adaptive to certain vehicles with high ***,even at low speed,the evaporation induced by liquid-gas-solid interface of a transverse microgrooved surface for continued gas supply has been discovered,which should be a promising method for practical application of underwater drag reduction by gas.

关键词： drag reduction entrapped gas skin friction underwater

Hydrothermal and sulfur aging of CeTi/CeWTi catalysts for selective catalytic reduction of NOx with NH3

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Journal of Rare Earths 2019年第8期37卷 829-836,I0002页

作者： Lei Chen Ding wang jiadao wang Duan Weng Li Cao State Key Laboratory of Tribology School of Mechanical EngineeringTsinghua UniversityBeijing 100084China Key Laboratory of Advanced Materials of Ministry of Education School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

The CeO2-TiO2(CeTi)and CeO2/WO3-TiO2(CeWTi)catalysts were prepared by sol-gel *** asprepared catalysts were hydrothermally treated at 760℃for 48 h in air containing 10 vol%H2O to obtain the hydrothermal aged *** sulfur aged catalysts were treated at 400℃with 100 ppm SO2,10%water vapor,air balance for 48 h and *** powder X-ray diffraction(XRD)and Raman results indicate that the crystallization of hydrothermal aged catalysts is more serious than sulfur aged *** addition,tungsten species can stabilize the CeTi catalyst from grain *** to the results of in situ diffuse reflectance infrared Fourier transform spectra(DRIFTS),temperatureprogrammed desorption of ammonia(NH3-TPD),H2 temperature-programmed reduction(H2-TPR)and ammonia oxidation,the aging process leads to loss of surface area,redox properties,surface acidities and surface ceria concentration,especially for the hyd rothermal *** NH3-NO/NO2 SCR perfo rmances of sulfur aged catalysts are better than that of hydrothermal aged *** with CeTi catalyst,the addition of tungsten inhibits the crystallization of *** that more acid sites and active sites are *** is also the reason why tungsten addition improves the NH3-NO/NO2 SCR performance of CeTi catalyst.

关键词： CeWTi catalyst Crystallization Surface acidity Redox property SCR activity Rare earths

Chemical composition and Mott-Schottky analysis of passive film formed on G3 alloy in bicarbonate/carbonate buffer solution

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Acta Metallurgica Sinica(English Letters) 2010年第6期23卷 461-472页

作者： Dangguo LI Darong CHEN jiadao wang Haosheng CHEN State Key Laboratory of Tribology Tsinghua University Beijing 100084 China

The chemical composition and semi-conductive properties of passive film on nickel- based alloy （G3 alloy） in bicarbonate/carbonate buffer solution were investigated by Auger electron spectroscopy （AES）, X-ray photoelectron spectroscopy （XPS）, elec- trochemical impedance spectra （EIS） and Mott-Schottky plot. AES and XPS results showed that the passive film appeared double-layer structure, in which the inner film was composed of nickel oxide, the mixed nickel-chromium-molybdenum-manganese oxides were the major component of the outer film. The electrochemical results revealed that the factors including frequency, potential, time, temperature and pH value can affect the semi-conductive property, the doping densities decreased with increasing potential and pH value, prolonging time and decreasing temperature. According to the above results, it can be concluded that the film protection on the substrate was enhanced with increasing potential and pH value, prolonging time and decreasing temperature.

关键词： Nickel-based alloy Auger electron analysis (AES) X-ray photo- electron spectroscopy (XPS) Electrochemical impedance spectra (EIS) Mott-Schottky plot

Experimental study on the special shear thinning process of a kind of non-Newtonian fluid

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Science China(Technological Sciences) 2007年第2期50卷 138-143页

作者： CHEN HaoSheng CHEN DaRong wang jiadao LI YongJian State Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China

To study the effect of long chain molecule and surface active agent on non-Newtonian fluid properties, rheological experiments on two different fluids have been done. The first group of the fluid is the hydroxyethyl cellulose water solution, and the second is the water solution containing the mixture of dodecyl- triethyl ammonium bromide and lauryl sodium sulfate. With the increasing shear rate, shear thinning phenomenon appears in the first group of solution, and a spe- cial shear thickening-shear thinning phenomenon appears in the second group. It is considered that the special rheological phenomenon is caused by the difference between the aggregating and the departing speed of the colloidal particles formed in the fluid. The difference between the two speeds relates with the shear rate. The experiment results indicate that the rheological properties can be designed by choosing proper additives at a certain shear rate, and such a fluid with special vis- cosity variation should be included in the classification of the non-Newtonian fluid.

关键词： non-Newtonian fluid rheology shear thinning

Investigation on Electronic Property of Passive Film on Nickel in Bicarbonate/Carbonate Buffer Solution

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Chinese Journal of Chemistry 2011年第2期29卷 243-253页

作者： Li Dangguo wang jiadao Chen Haosheng Chen Darong State Key Laboratory of Tribology Tsinghua University Beijing 100084 China

The electronic properties of passive film formed on nickel in bicarbonate/carbonate buffer solution were studied by electrochemical impedance spectra （EIS） and Mott-Schottky plot. The film composition was analyzed by X-ray photoelectron spectroscopy （XPS）. The results showed that passive film exhibited p-type semi-conductive character, and the acceptor density （NA） decreased with increasing potential, prolonging time, decreasing temperature, increasing pH value and decreasing chloride/sulfur ions concentration. The transfer resistance and film resistance increased with the above factors changing. XPS results showed that passive film was composed of NiO and a little amount of Ni2O3.

关键词： nickel electrochemical impedance spectra (EIS) X-ray photoelectron spectroscopy (XPS) passive films