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Junhui Hu received his Ph.D. Degree from Tokyo Institute of Technology, Tokyo, Japan, in 1997, and B. E. and M. E. degrees in electrical engineering from Zhejiang University, Hangzhou, China, in 1986 and 1989, respectively. Currently he is a Chang-Jiang Distinguished Professor, China, and the deputy director of State Key Laboratory of Mechanics and Control of Mechanical Structures (NUAA), China. Dr. Hu was an assistant and associate professor at Nanyang Technological University, Singapore, from 2001 to 2010. His research interest is in ultrasonic sensors and actuators, ultrasonic nano fabrication, ultrasonic micro/nano/molecular manipulations, etc. He is the author and co-author of more than 300 papers and disclosed patents, including more than 100 full research papers published in SCI journals and 1 editorial review in an international journal. He is also the sole author of monograph book “Ultrasonic Micro/Nano Manipulations: Principles and Examples” (2014, World Scientific, London New Jersey Singapore). Dr. Hu won the Paper Prize from the Institute of Electronics, Information and Communication Engineers (Japan) as the first author in 1998, and his research work has been highlighted by 7 international scientific media. He is an editorial board member of four international journals, and has given 20 keynote/invited lectures at international conferences.
In this paper, a method to increase the output power of a button zinc–air battery by applying acoustofluidics induced by ultrasonic excitation to the battery is proposed and demonstrated. In the structural design of the device, a flat piezoelectric ring was bonded onto the top of the outer surface of the cathode shell to excite an ultrasonic field in the battery. The maximum output power of the zinc–air battery increased by 46.8% when the vibration velocity and working frequency were 52.8 mm/s (the corresponding vibration amplitude was 277 nm) and 161.2 kHz and the rating capacity increased by about 20% with the assistance of the acoustofluidic field induced by ultrasonic excitation. Further analyses indicated that the discharge performance improvement can be attributed to the acoustic microstreaming vortices and the decrease of the viscosity coefficient in the electrolyte solution, which were both caused by ultrasonic excitation of the piezoelectric ring.
Zhao Luo; Qiang Tang; Junhui Hu. Effect of Ultrasonic Excitation on Discharge Performance of a Button Zinc–Air Battery. Micromachines 2021, 12, 792 .
AMA StyleZhao Luo, Qiang Tang, Junhui Hu. Effect of Ultrasonic Excitation on Discharge Performance of a Button Zinc–Air Battery. Micromachines. 2021; 12 (7):792.
Chicago/Turabian StyleZhao Luo; Qiang Tang; Junhui Hu. 2021. "Effect of Ultrasonic Excitation on Discharge Performance of a Button Zinc–Air Battery." Micromachines 12, no. 7: 792.
In this work, a cooling strategy, which employs focused ultrasound in air to cool small solid heat sources, is proposed and its characteristics are investigated. Analyses of the FEM computational and experimental results indicate that the cooling effect results from a forced convective heat transfer generated by the acoustic streaming at the focal region. By this cooling method, the heat flux is increased by 150 % and Nusselt number is doubled approximately for an ellipsoidal heat source made of Pt wire with a surface area of 6.44 mm2 and temperature of 100 °C, compared to natural convection. It is experimentally demonstrated that employing the flexural vibration mode of the acoustic lens is critical in the cooling device design, and increasing the vibration velocity and working frequency properly can further enhance the cooling effect. The method is also effective to a disc heat source with a surface diameter of 9 mm. Compared with the axial-fan cooling, the method proposed in this work does not use a rotary part (thus no dust accumulation, silent operation and ease of miniaturization) and has a faster cooling response.
Yang Hu; Zhao Luo; Yuchen Zhou; Junhui Hu. A Focused Ultrasound Based Cooling Strategy for Small Solid Heat Sources. Sensors and Actuators A: Physical 2021, 331, 112932 .
AMA StyleYang Hu, Zhao Luo, Yuchen Zhou, Junhui Hu. A Focused Ultrasound Based Cooling Strategy for Small Solid Heat Sources. Sensors and Actuators A: Physical. 2021; 331 ():112932.
Chicago/Turabian StyleYang Hu; Zhao Luo; Yuchen Zhou; Junhui Hu. 2021. "A Focused Ultrasound Based Cooling Strategy for Small Solid Heat Sources." Sensors and Actuators A: Physical 331, no. : 112932.
Flexible strain sensors with large stretchability, high sensitivity and good stability are highly desirable because of their potential applications in electronic skins and health monitoring systems. In this work, a liquid power-ultrasound based fabrication process for flexible strain sensors is reported. This method uses the acoustic cavitation and acoustic streaming in multi-walled carbon nanotube (MWCNT) water solution sonicated by power ultrasound of 19.9 kHz, to deposit MWCNT nanomaterials onto a 200 μm-thick polydimethylsiloxane (PDMS) substrate. The prepared strain sensor has a wide sensing range (≥420 % strain), high sensitivity (gauge factor, GF=8.4~68.3) and excellent stability (>10000 cycles at 50 % strain). The fabrication process is implemented at room temperature (25℃) and normal pressure (1 atm), and does not cause the atomization of nano solution. Also, it uses a minimum quantity of organic solvent (N,N-Dimethylformamide, DMF) as the disperser, and the remained MWCNTs in the fabrication process can be recycled. Apart from these green features, the fabrication process is not selective to the nano materials in the solution. Therefore, the proposed technique can be used in the fabrication of flexible strain sensors, electronic skin, and other flexible nano devices in an environment friendly way.
Hao Xue; Junhui Hu. A liquid power-ultrasound based green fabrication process for flexible strain sensors at room temperature and normal pressure. Sensors and Actuators A: Physical 2021, 329, 112822 .
AMA StyleHao Xue, Junhui Hu. A liquid power-ultrasound based green fabrication process for flexible strain sensors at room temperature and normal pressure. Sensors and Actuators A: Physical. 2021; 329 ():112822.
Chicago/Turabian StyleHao Xue; Junhui Hu. 2021. "A liquid power-ultrasound based green fabrication process for flexible strain sensors at room temperature and normal pressure." Sensors and Actuators A: Physical 329, no. : 112822.
The micromanipulation probe-type (MMP-type) ultrasonic nanomotor (UNM) has proven to be a type of robust and versatile tool for controllable rotary driving, dynamic trapping and high-precision orientation of a single one-dimensional (1D) nano object. The manipulation functions of the MMP-type UNM are implemented in the probe-liquid-substrate (PLS) system, in which a MMP is inserted into a liquid film of nano suspension on a stationary substrate. When the MMP elliptically vibrates parallel to the substrate surface, the acoustic streaming can be engendered to rotate a single silver nanowire (AgNW) at the liquid-substrate interface. Although the experimental results have demonstrated the effectiveness and high performance of the developed UNM, there have been no simulation results and quantitative analysis method to show the details of acoustic streaming field and to perform principle analysis for the MMP-type UNM, which has hindered a deeper understanding of the underlying physical mechanisms as well as optimization for the MMP-type UNM. In this work, to deeply analyze the principle for our developed UNM, we carry out numerical investigations on the thermo-viscous acoustic field and acoustic streaming field in the PLS system of the MMP-type UNM based on the finite element method (FEM). The simulation result shows that the elliptical vibration of the MMP parallel to the substrate surface can induce the reversed acoustic streaming vortex (compared to the MMP’s vibration trajectory direction) at the liquid-substrate interface, which enables controllable rotary driving of a single AgNW. With the simulation results of acoustic streaming fields, we theoretically predict the driving angular velocities of the AgNW at the liquid-substrate interface, and verify that the quantitative simulation results agree well with the reported experimental results. Moreover, the effects of device’s parameters and working conditions such as the distance between the MMP’s tip and substrate surface, the MMP’s length and radius and the liquid film’s thickness on the acoustic streaming field and the angular velocity of the AgNW are analyzed and clarified through both simulation results and experimental verifications, and the effect of the MMP’s material is also predicted via simulations.
Pengzhan Liu; Qiang Tang; Songfei Su; Junhui Hu. Principle analysis for the micromanipulation probe-type ultrasonic nanomotor. Sensors and Actuators A: Physical 2020, 318, 112524 .
AMA StylePengzhan Liu, Qiang Tang, Songfei Su, Junhui Hu. Principle analysis for the micromanipulation probe-type ultrasonic nanomotor. Sensors and Actuators A: Physical. 2020; 318 ():112524.
Chicago/Turabian StylePengzhan Liu; Qiang Tang; Songfei Su; Junhui Hu. 2020. "Principle analysis for the micromanipulation probe-type ultrasonic nanomotor." Sensors and Actuators A: Physical 318, no. : 112524.
Controllable manipulation of micro/nano-particles and biological organisms are essential for the engineering development of miniaturized lab-on-a-chip systems in the application of physical, chemical, and biological researches. In this paper, a series of phononic crystal structure based acoustofluidic devices, which are actuated by incident plane wave at different frequencies, have been proposed and numerically investigated for micro-particle manipulation. The interaction between different phononic crystal structures and ultrasonic waves, providing reflection, scattering and diffraction, can generate diverse spatial variations of sound field distribution along the wave propagation path. The combination of phononic crystal structures and lab-on-a-chip devices is beneficial to overcome the monotonousness of the acoustofluidic field distribution for various physical and biochemical applications. The movement trajectories of micro-particles under the influence of acoustic radiation forces and acoustic streaming induced drag forces are also simulated to demonstrate the particle manipulation capability of the designed acoustofluidic device. Our simulation results suggest the possibility of considering phononic crystal structures as an effective ingredient to customize acoustofluidic field for constituting diverse lab-on-a-chip devices in the investigation of rapid microfluidic mixing and non-invasive manipulation of bio-organisms.
Qiang Tang; Pengzhan Liu; Xin Guo; Song Zhou; Yuwei Dong. 2D acoustofluidic patterns in an ultrasonic chamber modulated by phononic crystal structures. Microfluidics and Nanofluidics 2020, 24, 1 -22.
AMA StyleQiang Tang, Pengzhan Liu, Xin Guo, Song Zhou, Yuwei Dong. 2D acoustofluidic patterns in an ultrasonic chamber modulated by phononic crystal structures. Microfluidics and Nanofluidics. 2020; 24 (12):1-22.
Chicago/Turabian StyleQiang Tang; Pengzhan Liu; Xin Guo; Song Zhou; Yuwei Dong. 2020. "2D acoustofluidic patterns in an ultrasonic chamber modulated by phononic crystal structures." Microfluidics and Nanofluidics 24, no. 12: 1-22.
Controllable enrichment of micro/nanoscale objects plays a significant role in many biomedical and biochemical applications, such as increasing the detection sensitivity of assays, or improving the structures of bio-engineered tissues.
Pengzhan Liu; Zhenhua Tian; Nanjing Hao; Hunter Bachman; Peiran Zhang; Junhui Hu; Tony Jun Huang. Acoustofluidic multi-well plates for enrichment of micro/nano particles and cells. Lab on a Chip 2020, 20, 1 .
AMA StylePengzhan Liu, Zhenhua Tian, Nanjing Hao, Hunter Bachman, Peiran Zhang, Junhui Hu, Tony Jun Huang. Acoustofluidic multi-well plates for enrichment of micro/nano particles and cells. Lab on a Chip. 2020; 20 (18):1.
Chicago/Turabian StylePengzhan Liu; Zhenhua Tian; Nanjing Hao; Hunter Bachman; Peiran Zhang; Junhui Hu; Tony Jun Huang. 2020. "Acoustofluidic multi-well plates for enrichment of micro/nano particles and cells." Lab on a Chip 20, no. 18: 1.
The development of ultrasonic tweezers with multiple manipulation functions is challenging. In this work, multiple advanced manipulation functions are implemented for a single probe-type ultrasonic tweezer with the double-parabolic-reflector wave-guided high-power ultrasonic transducer (DPLUS). Due to strong high-frequency (1.49 MHz) linear vibration at the manipulation probe’s tip, which is excited by the DPLUS, the ultrasonic tweezer can capture micro-objects in a non-contact mode and transport them freely above the substrate. Captured micro-objects that adhere to the probe’s tip in the low-frequency (154.4 kHz) working mode can be released by tuning the working frequency. Results of the finite element method analyses indicate that the manipulations are caused by the acoustic radiation force.
Qingyang Liu; Kang Chen; Junhui Hu; Takeshi Morita. An Ultrasonic Tweezer With Multiple Manipulation Functions Based on the Double-Parabolic-Reflector Wave-Guided High-Power Ultrasonic Transducer. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 2020, 67, 2471 -2474.
AMA StyleQingyang Liu, Kang Chen, Junhui Hu, Takeshi Morita. An Ultrasonic Tweezer With Multiple Manipulation Functions Based on the Double-Parabolic-Reflector Wave-Guided High-Power Ultrasonic Transducer. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control. 2020; 67 (11):2471-2474.
Chicago/Turabian StyleQingyang Liu; Kang Chen; Junhui Hu; Takeshi Morita. 2020. "An Ultrasonic Tweezer With Multiple Manipulation Functions Based on the Double-Parabolic-Reflector Wave-Guided High-Power Ultrasonic Transducer." IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 67, no. 11: 2471-2474.
Gas identification by a single sensing element is a challenging and promising technology. In this work, a novel strategy to identify gases by a single catalytic combustible sensor working in its linear range is proposed and investigated. In the strategy, a half-wavelength standing wave ultrasonic field is used to catalyze the combustion reaction on the sensing surface, and quantified ultrasonic enhancement effect on the sensing response, which is independent of the gas concentration and varies with the species of analyte gases, is employed to identify the gases. The experimental results show that the success rate of gas identification can reach 100 % when the ultrasonic vibration is strong enough, and the gas identification method has anti-interference capability when there is impurity gas in the target gas. The cause of the anti-interference capability is analyzed. The strategy proposed in this work provides a new design way which can make the structure, data processing and calibration of gas identification systems simpler.
Tianyu Zhang; Yuchen Zhou; Pengzhan Liu; Junhui Hu. A novel strategy to identify gases by a single catalytic combustible sensor working in its linear range. Sensors and Actuators B: Chemical 2020, 321, 128514 .
AMA StyleTianyu Zhang, Yuchen Zhou, Pengzhan Liu, Junhui Hu. A novel strategy to identify gases by a single catalytic combustible sensor working in its linear range. Sensors and Actuators B: Chemical. 2020; 321 ():128514.
Chicago/Turabian StyleTianyu Zhang; Yuchen Zhou; Pengzhan Liu; Junhui Hu. 2020. "A novel strategy to identify gases by a single catalytic combustible sensor working in its linear range." Sensors and Actuators B: Chemical 321, no. : 128514.
Controlled capture of single biological micro particles, with effective capture function, little heat damage to and good stability of captured samples simultaneously, has been a technological challenge in the area of micro manipulation. This paper presents an ultrasonic tweezers based new strategy to meet the challenge. In the strategy, being different from the other ultrasonic methods, the MMP (micro manipulating probe), which vibrates elliptically, is in contact with the substrate. Single yeast cells with a diameter of 3–7 μm and Chlorella vulgaris powders with a diameter of 2–10 μm near the MMP can be sucked onto the MMP’s tip. The captured particle can be transferred to a desired location at the interface between the water film and substrate by moving the ultrasonic tweezers. The temperature rise in the capture region is less than 0.1 °C, and the sucking distance can be up to 20 μm. The captured particle is in contact with the MMP’s tip, which results in a good stability of the captured particle. The experiments also show that it is possible to use multiple MMPs to individually capture single cells. The finite element analyses indicate that acoustic radiation force generated by the ultrasonic field around the MMP is responsible for the capture. Moreover, the effects of the orthogonal vibration components, tilt angle and length of the MMP on the capture capability are clarified.
Qingyang Liu; Qiang Tang; Junhui Hu. A new strategy to capture single biological micro particles at the interface between a water film and substrate by ultrasonic tweezers. Ultrasonics 2020, 103, 106067 .
AMA StyleQingyang Liu, Qiang Tang, Junhui Hu. A new strategy to capture single biological micro particles at the interface between a water film and substrate by ultrasonic tweezers. Ultrasonics. 2020; 103 ():106067.
Chicago/Turabian StyleQingyang Liu; Qiang Tang; Junhui Hu. 2020. "A new strategy to capture single biological micro particles at the interface between a water film and substrate by ultrasonic tweezers." Ultrasonics 103, no. : 106067.
The probe-type and substrate-type ultrasonic micro/nano manipulation systems have proven to be two kinds of powerful tools for manipulating micro/nanoscale materials. Numerical simulations of acoustofluidic fields in these two kinds of systems can not only be used to explain and analyze the physical mechanisms of experimental phenomena, but also provide guidelines for optimization of device parameters and working conditions. However, in-depth quantitative study and analysis of acoustofluidic fields in the two ultrasonic micro/nano manipulation systems have scarcely been reported. In this paper, based on the finite element method (FEM), we numerically investigated the two-dimensional (2D) axisymmetric acoustofluidic fields in the probe-type and substrate-type ultrasonic micro/nano manipulation systems by the perturbation method (PM) and Reynolds stress method (RSM), respectively. Through comparing the simulation results computed by the two methods and the experimental verifications, the feasibility and reasonability of the two methods in simulating the acoustofluidic fields in these two ultrasonic micro/nano manipulation systems have been validated. Moreover, the effects of device parameters and working conditions on the acoustofluidic fields are clarified by the simulation results and qualitatively verified by the experiments.
Pengzhan Liu; Qiang Tang; Songfei Su; Jie Hu; Yang Yu. Modeling and Analysis of the Two-Dimensional Axisymmetric Acoustofluidic Fields in the Probe-Type and Substrate-Type Ultrasonic Micro/Nano Manipulation Systems. Micromachines 2019, 11, 22 .
AMA StylePengzhan Liu, Qiang Tang, Songfei Su, Jie Hu, Yang Yu. Modeling and Analysis of the Two-Dimensional Axisymmetric Acoustofluidic Fields in the Probe-Type and Substrate-Type Ultrasonic Micro/Nano Manipulation Systems. Micromachines. 2019; 11 (1):22.
Chicago/Turabian StylePengzhan Liu; Qiang Tang; Songfei Su; Jie Hu; Yang Yu. 2019. "Modeling and Analysis of the Two-Dimensional Axisymmetric Acoustofluidic Fields in the Probe-Type and Substrate-Type Ultrasonic Micro/Nano Manipulation Systems." Micromachines 11, no. 1: 22.
It is known that the ultrasound assisted metal oxide semiconductor (MOS) gas sensor system can improve the sensitivity and lower detection limit (LDL) of a MOS gas sensor. The existing ultrasound assisted MOS gas sensor system employs the standing-wave ultrasonic field. As the size of the sensing element is much smaller than that of the ultrasonic field, energy utilization rate of the ultrasonic subsystem has been very poor. In this work, we propose a method to raise the energy utilization rate and the limit sensing properties of the ultrasound assisted MOS gas sensor system, which utilizes the focused ultrasound generated by a low-frequency ultrasonic transducer with a concave radiation face. By placing the sensing element at the focal region, the electric power input of the ultrasonic transducer can be decreased by about 50% for the same sensing response. Moreover, the maximum sensitivity can be increased by 45%, and the LDL can be decreased by 50% by the new method.
Songfei Su; Xiaomin Qi; Pengzhan Liu; Junhui Hu. Focused Ultrasound Assistance to the MOS Gas Sensor System. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 2019, 67, 1009 -1016.
AMA StyleSongfei Su, Xiaomin Qi, Pengzhan Liu, Junhui Hu. Focused Ultrasound Assistance to the MOS Gas Sensor System. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control. 2019; 67 (5):1009-1016.
Chicago/Turabian StyleSongfei Su; Xiaomin Qi; Pengzhan Liu; Junhui Hu. 2019. "Focused Ultrasound Assistance to the MOS Gas Sensor System." IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 67, no. 5: 1009-1016.
Two-dimensional acoustofluidic fields in an ultrasonic chamber actuated by segmented ring-shaped vibration sources with different excitation phases are simulated by COMSOL Multiphysics. Diverse acoustic streaming patterns, including aggregation and rotational modes, can be feasibly generated by the excitation of several sessile ultrasonic sources which only vibrate along radial direction. Numerical simulation of particle trajectory driven by acoustic radiation force and streaming-induced drag force also demonstrates that micro-scale particles suspended in the acoustofluidic chamber can be trapped in the velocity potential well of fluid flow or can rotate around the cavity center with the circumferential acoustic streaming field. Preliminary investigation of simple Russian doll- or Matryoshka-type configurations (double-layer vibration sources) provide a novel method of multifarious structure design in future researches on the combination of phononic crystals and acoustic streaming fields. The implementation of multiple segmented ring-shaped vibration sources offers flexibility for the control of acoustic streaming fields in microfluidic devices for various applications. We believe that this kind of acoustofluidic design is expected to be a promising tool for the investigation of rapid microfluidic mixing on a chip and contactless rotational manipulation of biosamples, such as cells or nematodes.
Qiang Tang; Song Zhou; Liang Huang; Zhong Chen. Diversity of 2D Acoustofluidic Fields in an Ultrasonic Cavity Generated by Multiple Vibration Sources. Micromachines 2019, 10, 803 .
AMA StyleQiang Tang, Song Zhou, Liang Huang, Zhong Chen. Diversity of 2D Acoustofluidic Fields in an Ultrasonic Cavity Generated by Multiple Vibration Sources. Micromachines. 2019; 10 (12):803.
Chicago/Turabian StyleQiang Tang; Song Zhou; Liang Huang; Zhong Chen. 2019. "Diversity of 2D Acoustofluidic Fields in an Ultrasonic Cavity Generated by Multiple Vibration Sources." Micromachines 10, no. 12: 803.
The manipulation of motile and still single cells with the simultaneous features of selective trapping, 3-D path free transport, position-controllable release and little heat damage has been a significant challenge. We developed an ultrasonic method for capturing motile and still single cells with the aforementioned features in a droplet. During manipulation, a micromanipulation probe (MMP), which vibrated linearly with a trajectory parallel to a silicon substrate, was immersed in the droplet and was not in contact with the substrate. Motile and still single cells, such as Chattonella marina with a length of 30-50 μm and yeast cells with a diameter of 3-10 μm, at the interface between the droplet and substrate were selectively sucked onto the vibrating MMP and transported via a 3-D route inside the droplet by moving the MMP (or the device). The MMP and captured single cells were in contact, making the release position controllable. The measured temperature rise of the MMP was <0.1°C; thus, it is competitive for the manipulation of biological samples. Finite-element analyses revealed that the contact-type capture was due to acoustic radiation force generated by the ultrasonic field around the vibrating MMP. The dependence of the capture capability and working frequency bandwidth on the working conditions was investigated experimentally.
Qingyang Liu; Junhui Hu; Igor Minin; Oleg V. Minin. High-Performance Ultrasonic Tweezers for Manipulation of Motile and Still Single Cells in a Droplet. Ultrasound in Medicine & Biology 2019, 45, 3018 -3027.
AMA StyleQingyang Liu, Junhui Hu, Igor Minin, Oleg V. Minin. High-Performance Ultrasonic Tweezers for Manipulation of Motile and Still Single Cells in a Droplet. Ultrasound in Medicine & Biology. 2019; 45 (11):3018-3027.
Chicago/Turabian StyleQingyang Liu; Junhui Hu; Igor Minin; Oleg V. Minin. 2019. "High-Performance Ultrasonic Tweezers for Manipulation of Motile and Still Single Cells in a Droplet." Ultrasound in Medicine & Biology 45, no. 11: 3018-3027.
Xiaomin Qi; Pengzhan Liu; Junhui Hu. Erratum: A low temperature-rise and facile manipulation method for single micro objects at the air-substrate interface (2019 J. Micromech. Microeng. 29 105007). Journal of Micromechanics and Microengineering 2019, 29, 119601 .
AMA StyleXiaomin Qi, Pengzhan Liu, Junhui Hu. Erratum: A low temperature-rise and facile manipulation method for single micro objects at the air-substrate interface (2019 J. Micromech. Microeng. 29 105007). Journal of Micromechanics and Microengineering. 2019; 29 (11):119601.
Chicago/Turabian StyleXiaomin Qi; Pengzhan Liu; Junhui Hu. 2019. "Erratum: A low temperature-rise and facile manipulation method for single micro objects at the air-substrate interface (2019 J. Micromech. Microeng. 29 105007)." Journal of Micromechanics and Microengineering 29, no. 11: 119601.
Zhao Luo; Qiang Tang; Songfei Su; Junhui Hu. A high-performance structure for the bulk acoustic wave metal oxide semiconductor gas sensor. Smart Materials and Structures 2019, 28, 105015 .
AMA StyleZhao Luo, Qiang Tang, Songfei Su, Junhui Hu. A high-performance structure for the bulk acoustic wave metal oxide semiconductor gas sensor. Smart Materials and Structures. 2019; 28 (10):105015.
Chicago/Turabian StyleZhao Luo; Qiang Tang; Songfei Su; Junhui Hu. 2019. "A high-performance structure for the bulk acoustic wave metal oxide semiconductor gas sensor." Smart Materials and Structures 28, no. 10: 105015.
The gas identification technology has huge potential applications in medical diagnoses, food industries, early warning of poisonous gas leakage, fire prevention, antiterrorism, military, etc. Although electronic noses may be used to identify different gases, it has been a big challenge to identify gases by a single sensor. In this work, we demonstrate a novel gas identification strategy based on a single metal-oxide-semiconductor (MOS) sensor assisted by an ultrasound. The identification is based on different ultrasonic effects on the steady sensing responses of an ultrasonically radiated MOS gas sensor to different target gases. It does not need a complicated feature extraction computation. Our experiments show that the success rate of identification can be up to 100% if strong enough ultrasound is employed. The identification process can also give the concentration of the gas to be identified. The identification result is immune to the interference of impurity gases to some extent. The anti-interference capability may be strengthened by increasing the vibration velocity and choosing proper sensing materials.
Songfei Su; Junhui Hu. Gas Identification by a Single Metal-Oxide-Semiconductor Sensor Assisted by Ultrasound. ACS Sensors 2019, 4, 2491 -2496.
AMA StyleSongfei Su, Junhui Hu. Gas Identification by a Single Metal-Oxide-Semiconductor Sensor Assisted by Ultrasound. ACS Sensors. 2019; 4 (9):2491-2496.
Chicago/Turabian StyleSongfei Su; Junhui Hu. 2019. "Gas Identification by a Single Metal-Oxide-Semiconductor Sensor Assisted by Ultrasound." ACS Sensors 4, no. 9: 2491-2496.
Convenient and high-efficiency manipulation of nanoscale materials has huge potential applications in nano assembly and biomedical technology. We have reported an ultrasonic needle-droplet-substrate system to aggregate and then transport the nanoscale materials freely at the interface between the substrate and water droplet. In the manipulation method, the ultrasonic needle is inserted into the water droplet of nanoscale material to generate a controlled ultrasonic field for the manipulations. In this paper, we report the detailed method and results of FE (finite element) analyses for the investigation of working principle of the manipulation system. The FE analyses show that the ultrasonic needle can generate an acoustic streaming field around the ultrasonic needle to implement the nano aggregation and transportation. The computational results can well explain the experimental phenomena of multiple-function manipulation.
Xiaomin Qi; Qiang Tang; Pengzhan Liu; Junhui Hu. Finite Element Analyses of Working Principle of the Ultrasonic Needle-Droplet-Substrate System for Multiple-Function Manipulation. Algorithms and Data Structures 2019, 227 -233.
AMA StyleXiaomin Qi, Qiang Tang, Pengzhan Liu, Junhui Hu. Finite Element Analyses of Working Principle of the Ultrasonic Needle-Droplet-Substrate System for Multiple-Function Manipulation. Algorithms and Data Structures. 2019; ():227-233.
Chicago/Turabian StyleXiaomin Qi; Qiang Tang; Pengzhan Liu; Junhui Hu. 2019. "Finite Element Analyses of Working Principle of the Ultrasonic Needle-Droplet-Substrate System for Multiple-Function Manipulation." Algorithms and Data Structures , no. : 227-233.
Xiaomin Qi; Pengzhan Liu; Junhui Hu. A low temperature-rise and facile manipulation method for single micro objects at the air-substrate interface. Journal of Micromechanics and Microengineering 2019, 29, 105007 .
AMA StyleXiaomin Qi, Pengzhan Liu, Junhui Hu. A low temperature-rise and facile manipulation method for single micro objects at the air-substrate interface. Journal of Micromechanics and Microengineering. 2019; 29 (10):105007.
Chicago/Turabian StyleXiaomin Qi; Pengzhan Liu; Junhui Hu. 2019. "A low temperature-rise and facile manipulation method for single micro objects at the air-substrate interface." Journal of Micromechanics and Microengineering 29, no. 10: 105007.
Controlled concentration of nanoscale materials on the surface of a smooth substrate without vibration excitation mechanism and micro channels (termed as plain substrate), and transportation of the concentrated nano material on the surface, have large potential applications in the fabrication of nano sensors and electrodes, decoration and assembly of nano materials, etc. However, implementation of these two nano manipulation functions by one single device has been a big challenge. Here we report a strategy to concentrate nanoparticles at an arbitrary location at the interface between a plain substrate and water droplet, and to transportation the concentrated nano material freely at the interface. It employs the acoustic streaming, which is generated by a micro manipulating probe (MMP) vibrating linearly above the substrate. 500 nm-diameter silicon nanoparticles (SiNPs) can be concentrated under the MMP at a desired location, forming a round spot of nano materials with a diameter up to 230 μm. The concentrated nano material can be transported through an arbitrary path at the interface by shifting the device, and has little change in size and shape during the transportation. The dependency of acoustic streaming field around the MMP on device parameters are clarified by numerical computation and verified by experiments.
Xiaomin Qi; Qiang Tang; Pengzhan Liu; Igor Minin; Oleg V. Minin; Junhui Hu. Controlled concentration and transportation of nanoparticles at the interface between a plain substrate and droplet. Sensors and Actuators B: Chemical 2018, 274, 381 -392.
AMA StyleXiaomin Qi, Qiang Tang, Pengzhan Liu, Igor Minin, Oleg V. Minin, Junhui Hu. Controlled concentration and transportation of nanoparticles at the interface between a plain substrate and droplet. Sensors and Actuators B: Chemical. 2018; 274 ():381-392.
Chicago/Turabian StyleXiaomin Qi; Qiang Tang; Pengzhan Liu; Igor Minin; Oleg V. Minin; Junhui Hu. 2018. "Controlled concentration and transportation of nanoparticles at the interface between a plain substrate and droplet." Sensors and Actuators B: Chemical 274, no. : 381-392.
Silver nano sheets (AgNSs) have very good potential applications in fabrication of photonic devices and nano sensors, and chemical methods have been the major means to fabricate it. Here, we report a mechanical method to on-site fabricate AgNSs on a solid substrate by a nano rolling process. In the method, a flexible ultrasonic micro tool is proposed and utilized to roll commercialized AgNWs and micro Ag particles into AgNSs. The thickness of fabricated AgNSs can be as thin as several tens of nanometers, and it may be further decreased by using thinner AgNWs as the raw material and optimizing the structure and working conditions of the micro tool. The rolling effect is not sensitive to the preload when the micro tool vibration is sufficiently large, and the vibrating micro tool does not damage the substrate due to the circular shape of the micro tool.
Xu Wang; Junhui Hu. A flexible ultrasonic micro tool-based AgNS fabrication process. Applied Nanoscience 2018, 8, 1579 -1586.
AMA StyleXu Wang, Junhui Hu. A flexible ultrasonic micro tool-based AgNS fabrication process. Applied Nanoscience. 2018; 8 (6):1579-1586.
Chicago/Turabian StyleXu Wang; Junhui Hu. 2018. "A flexible ultrasonic micro tool-based AgNS fabrication process." Applied Nanoscience 8, no. 6: 1579-1586.