In this study,the design and development of a sensor made of low-cost parts to monitor inclination and acceleration are presented.Αmicro electro-mechanical systems,micro electro mechanical systems,sensor was housed i...In this study,the design and development of a sensor made of low-cost parts to monitor inclination and acceleration are presented.Αmicro electro-mechanical systems,micro electro mechanical systems,sensor was housed in a robust enclosure and interfaced with a Raspberry Pi microcomputer with Internet connectivity into a proposed tilt and acceleration monitoring node.Online capabilities accessible by mobile phone such as real-time graph,early warning notification,and database logging were implemented using Python programming.The sensor response was calibrated for inherent bias and errors,and then tested thoroughly in the laboratory under static and dynamic loading conditions beside high-quality transducers.Satisfactory accuracy was achieved in real time using the Complementary Filter method,and it was further improved in LabVIEW using Kalman Filters with parameter tuning.A sensor interface with LabVIEW and a 600 MHz CPU microcontroller allowed real-time implementation of highspeed embedded filters,further optimizing sensor results.Kalman and embedded filtering results show agreement for the sensor,followed closely by the lowcomplexity complementary filter applied in real time.The sensor's dynamic response was also verified by shaking table tests,simulating past recorded seismic excitations or artificial vibrations,indicating negligible effect of external acceleration on measured tilt;sensor measurements were benchmarked using highquality tilt and acceleration measuring transducers.A preliminary field evaluation shows robustness of the sensor to harsh weather conditions.展开更多
The integration method of exploding foil initiator system(EFIs) used to be researched to broaden its application range in military and aerospace in the last few decades.In order to lower the firing voltage below 1 kV,...The integration method of exploding foil initiator system(EFIs) used to be researched to broaden its application range in military and aerospace in the last few decades.In order to lower the firing voltage below 1 kV,an integrated EFIs with enhanced energy efficiency was designed.Corresponding exploding foil initiator chips were fabricated in batch via micro electromechanical systems technology by integrating a unified foil,a flyer layer and a barrel on a glass substrate successively,meanwhile its package of the whole system was proposed at a volume of 2.194 cm^(3).The structural parameters were determined by predicted performance including flyer velocity,impact behavior and conduction property via the proposed theoretical models and the static electric field simulation.As expect,this integrated EFIs exhibited excellent functions,which could accelerate the flyer to a terminal velocity over 4 km/s and preeminently initiate HNS-IV pellet at a circuit of 0.24 μF/0.9 kV.Furthermore,the theoretical design,fabrication and performance test have been all included to validate the feasibility of this integrated EFIs that was beneficial for its commercial development in the future.展开更多
The mode coupling is a major factor to affect the precision of the micro electromechanical systems(MEMS)gyroscope.Currently,many MEMS gyroscopes with separate oscillation modes for drive and detection have been develo...The mode coupling is a major factor to affect the precision of the micro electromechanical systems(MEMS)gyroscope.Currently,many MEMS gyroscopes with separate oscillation modes for drive and detection have been developed to decrease the mode coupling,but the gyroscope accuracy can not satisfy the high-precision demand well.Therefore,high performance decoupled MEMS gyroscopes is still a hot topic at present.An innovative design scheme for a MEMS gyroscope is designed,and in this design,the inertial mass is divided into three parts including the inner mass,the outer mass and the main frame mass.The masses are supported and separated by a set of mutually orthogonal beams to decouple their movements.Moreover,the design is modelled by multi-port-element network(MuPEN)method and the simulation results show that the mode coupling of the gyroscope between driving and sensing mode was eliminated effectively.Furthermore,we proposed a new silicon-on-insulator(SOI)process to fabricate the gyroscope.The scale factor of the fabricated gyroscope is 8.9 mV/((~)os)and the quality factor(Q-factor)is as high as 600 at atmosphere pressure,and then,the resonant frequency,scale factor and bias drift has been test.Process and test results show that the proposed MEMS gyroscope are effective for decrease mode coupling,furthermore,it can achieve a high performance at atmosphere pressure.Furthermore,the MEMS gyroscope can achieve a high performance at atmosphere pressure.The research can be taken as good advice for the design and fabrication of MEMS gyroscope,meanwhile,it also provides technical support for speeding up of MEMS gyroscope industrialization.展开更多
A new scheme is proposed to model 3D angular motion of a revolving regular object with miniature, low-cost micro electro mechanical systems(MEMS) accelerometers(instead of gyroscope),which is employed in 3D mouse syst...A new scheme is proposed to model 3D angular motion of a revolving regular object with miniature, low-cost micro electro mechanical systems(MEMS) accelerometers(instead of gyroscope),which is employed in 3D mouse system.To sense 3D angular motion,the static property of MEMS accelerometer,sensitive to gravity acceleration,is exploited.With the three outputs of configured accelerometers,the proposed model is implemented to get the rotary motion of the rigid object.In order to validate the effectiveness of the proposed model,an input device is developed with the configuration of the scheme.Experimental results show that a simulated 3D cube can accurately track the rotation of the input device.The result indicates the feasibility and effectiveness of the proposed model in the 3D mouse system.展开更多
Currently, the monitoring of bridges in China heavily relies on manual operation, which has several major problems. It generally takes a very long time to complete an inspection process on bridges. The manual data is ...Currently, the monitoring of bridges in China heavily relies on manual operation, which has several major problems. It generally takes a very long time to complete an inspection process on bridges. The manual data is sometimes unreliable or even wrong in the case of careless operation. The inspection activity itself is dangerous for inspectors, e.g., bridges are located in the sea or river. Some semi-automatic monitoring methods are recently employed, but they are either very expensive or do not work properly. Therefore, the traditional bridge monitoring process becomes an increasing challenge for bridge operators. In this paper, a real-time and automatic bridge monitoring system is presented to meet the bridge monitoring needs, and MEMS （Micro Electro Mechanical Systems） are the key building block in this system. By using the MEMS-based sensors, it is much more efficient and accurate in monitoring bridges with the measurement of inclination, acceleration, displacement, moisture, temperature, stress and other data.展开更多
The development of personalized healthcare is rapidly growing thanks to the support of low-power electronics,advanced fabrication processes and secured data transmission protocols.Long-acting drug delivery systems abl...The development of personalized healthcare is rapidly growing thanks to the support of low-power electronics,advanced fabrication processes and secured data transmission protocols.Long-acting drug delivery systems able to sustain the release of therapeutics in a controllable manner can provide several advantages in the treatment of chronic diseases.Various systems under development control drug release from an implantable reservoir via concentration driven diffusion through nanofluidic membranes.Given the high drug concentration in the reservoir,an inward osmotic fluid transport occurs across the membrane,which counters the outward diffusion of drugs.The resulting osmotic pressure buildup may be sufficient to cause the failure of implants with associated risks to patients.Confidently assessing the osmotic pressure buildup requires testing in vivo.Here,using metal and polymer AM(additive manufacturing)processes,we designed and developed implantable drug reservoirs with embedded strain sensors to directly measure the osmotic pressure in drug delivery implants in vitro and in vivo.展开更多
The last half-century was transformed by the electronic revolution that essentially reproduced the human brain and its computing capacity on a chip. But over time, scientists have realized that something was missing t...The last half-century was transformed by the electronic revolution that essentially reproduced the human brain and its computing capacity on a chip. But over time, scientists have realized that something was missing to give life, so to speak, to the small chip with a brain： One needed to awaken its senses and develop its muscles! This challenge was solved through MEMS （micro electro mechanical systems）. Indeed, MEMS today are equipped with the sense of sight, smell, hearing, taste and touch through microsensors. They are also capable of physical exertion through small muscles called microactuators. These new capabilities open wide fields of imagination and important specific applications.展开更多
The particles suspending in liquid suffer acoustical radiation force from ultrasonic field. The force may cause particles movement and has special advantage to separate particles from liquid in Micro Electro Mechanica...The particles suspending in liquid suffer acoustical radiation force from ultrasonic field. The force may cause particles movement and has special advantage to separate particles from liquid in Micro Electro Mechanical Systems （MEMS）. It is important to improve the energy stored in liquid layer so as to increase separation ability for decreasing drive demand in MEMS. Resonance may hugely increase the magnitude and generally be employed in micro separator. The summits of admittance spectrum show the resonance frequencies. It may come from resonance in one layer or multi layers in micro separator. This paper studies the difference of energy stored in layers at each rein frequency. It provides the way to select the most effect separation frequency other than admittance spectrum.展开更多
Wireless communication systems which require flexibility and reconfigurability in antenna systems faces main problems like antenna performance, size, weight and cost. A wide band Frequency Reconfigurable Rectangular S...Wireless communication systems which require flexibility and reconfigurability in antenna systems faces main problems like antenna performance, size, weight and cost. A wide band Frequency Reconfigurable Rectangular Slotted Self Similar Antenna has been proposed in this paper. The rectangular slotted patch is repeated for two iterations at different scales and is separated by means of Radio Frequency Micro Electro Mechanical Systems (RF MEMS) switches in order to provide reconfigurability. The antenna can operate in three frequency bandsi.e. K-band, Ku-band and Ka-band by altering the states of RF MEMS switches. To avoid fringing effects and to improve antenna performance, quarter wavelength (λ/4) spacing is required between the antenna and the ground plane. However, a Reconfigurable Antenna requires different λ/4 spacing which is difficult to achieve using a common ground plane. So the Frequency Reconfigurable antenna is integrated with high impedance surface (HIS) like Electronic Band Gap (EBG) structures to suppress standing waves and surface waves with a unified profile thickness of 1.75 mm. The overall dimension of the proposed antenna along with RF MEMS Switch, feed element and HIS is about 8 mm × 8 mm × 1.75 mm. The simulated results of the proposed antenna reveal enhancement in antennas performance like Voltage Standing Wave Ratio (VSWR), Front to Back Ratio (FBR) and bandwidth when it is placed over HIS EBG. Also the radiation patterns of the proposed antenna when placed over EBG shows the suppression of side lobe and backward radiation.展开更多
The concept of micro-total analysis systems(µTAS)introduced in the early 1990s revolutionized the development of lab-on-a-chip(LoC)technologies by miniaturizing and automating complex laboratory processes.Despite...The concept of micro-total analysis systems(µTAS)introduced in the early 1990s revolutionized the development of lab-on-a-chip(LoC)technologies by miniaturizing and automating complex laboratory processes.Despite their potential in diagnostics,drug development,and environmental monitoring,the widespread adoption of LoC systems has been hindered by challenges in scalability,integration,and cost-effective mass production.Traditional substrates like silicon,glass,and polymers struggle to meet the multifunctional requirements of practical applications.Lab-on-Printed Circuit Board(Lab-on-PCB)technology has emerged as a transformative solution,leveraging the cost-efficiency,scalability,and precision of PCB fabrication techniques.This platform facilitates the seamless integration of microfluidics,sensors,and actuators within a single device,enabling complex,multifunctional systems suitable for real-world deployment.Recent advancements have demonstrated Lab-on-PCB’s versatility across biomedical applications,such as point-of-care diagnostics,electrochemical biosensing,and molecular detection,as well as drug development and environmental monitoring.This review examines the evolution of Lab-on-PCB technology over the past eight years,focusing on its applications and impact within the research community.By analyzing recent progress in PCB-based microfluidics and biosensing,this work highlights how Lab-on-PCB systems address key technical barriers,paving the way for scalable and practical lab-on-chip solutions.The growing academic and industrial interest in Lab-on-PCB is underscored by a notable increase in publications and patents,signaling its potential for commercialization and broader adoption.展开更多
Transparent conductive films that are based on nanowire networks are essential to construct flexible,wearable,and even stretchable electronics.However,large-scale precise micropatterning,especially with regard to the ...Transparent conductive films that are based on nanowire networks are essential to construct flexible,wearable,and even stretchable electronics.However,large-scale precise micropatterning,especially with regard to the controllability of the organizing orientation of nanowires,is a critical challenge.Herein,we proposed a liquid film rupture self-assembly approach for manufacturing transparent conductive films with microstructure arrays based on a highly ordered nanowire network.The large-scale microstructure conductive films were fabricated through air-liquid interface self-assembly and liquid film rupture self-assembly.Six typical micropattern morphologies,including square,hexagon,circle,serpentine,etc.,were prepared to reveal the universal applicability of the proposed approach.The homogeneity and controllability of this approach were verified for multiple assemblies.With the assembly cycles increasing,the optical transmittance decreases slightly.In addition,theoretical model analysis is carried out,and the analytical formula of the speed of the film moving with the surface tension and the density of the liquid film is presented.Finally,the feasibility of this approach for piezoresistive strain sensors is verified.This fabrication approach demonstrated a cost-effective and efficient method for precisely arranging nanowires,which is useful in transparent and wearable applications.展开更多
A new process and technology of rapid prototyping for a μ-micro motor is presented as a nontraditional machining and an advanced manufacturing technology (AMT) to be realized by using masks, including the operation p...A new process and technology of rapid prototyping for a μ-micro motor is presented as a nontraditional machining and an advanced manufacturing technology (AMT) to be realized by using masks, including the operation principle of the motor, structure design, technique, driven circuit, and quality examination with Raman spectrum. The μ-micro motor is fabricated by the micro electro-mechanical systems (MEMS) process, the structure design must be considered to fabricate or assembly the parts during machining the motor in the meantime. The research proved that integration of IC (integrated circuit) process and MEMS using masks is effective in obtaining the rapid prototyping manufacturing of the μ-micro motor. With the mature technique to fabricate the motor, there are advantages to produce the motor in short time and with lower cost than before. The motor is a common power source of micro machines in military and civilian applications, for example, applied to micro robot, micro bio medicine, and micro machine. The size of the motor is 190 μm in maximum diameter by 125 μm in height that is bulk machined in array with the number of hundreds of micro motors on a substrate.展开更多
A novel amperometric immunosensor based on the micro electromechanical systems （MEMS） technology, using protein A and self-assembled monolayers （SAMs） for the orientation-controlled immobilization of antibodies, h...A novel amperometric immunosensor based on the micro electromechanical systems （MEMS） technology, using protein A and self-assembled monolayers （SAMs） for the orientation-controlled immobilization of antibodies, has been developed. Using MEMS technology, an ＂Au, Pt, Pt＂ three-microelectrode system enclosed in a SU-8 micro pool was fabricated. Employing SAMs, a monolayer of protein A was immobilized on the cysteamine modified Au electrode to achieve the orientation-controlled immobilization of the human immunoglobulin （HIgG） antibody. The immunosensor aimed at low unit cost, small dimension, high level of integration and the prospect of a biosensor system-on-a-chip. Cyclic voltammetry and chronoamperometry were conducted to characterize the immunosensor. Compared with the traditional immunosensor using bulky gold electrode or screen-printed electrode and the procedure directly binding protein A to electrode for immobilization of antibodies, it had attractive advantages, such as miniaturization, compatibility with CMOS technology, fast response （30 s）, broad linear range （50-400 pg/L） and low detection limit （10 pg/L） for HIgG. In addition, this immunosensor was easy to be designed into micro array and to realize the simultaneously multi-parameter detection.展开更多
Small RNAs play an important role in plant immune responses. However, their regulatory function in induced systemic resistance（ISR） is nascent. Bacillus cereus AR156 is a plant growth-promoting rhizobacterium that i...Small RNAs play an important role in plant immune responses. However, their regulatory function in induced systemic resistance（ISR） is nascent. Bacillus cereus AR156 is a plant growth-promoting rhizobacterium that induces ISR in Arabidopsis against bacterial infection. Here,by comparing small RNA profiles of Pseudomonas syringae pv. tomato（Pst） DC3000-infected Arabidopsis with and without AR156 pretreatment, we identified a group of Arabidopsis micro RNAs（mi RNAs） that are differentially regulated by AR156 pretreatment. mi R825 and mi R825 are two mi RNA generated from a single mi RNA gene.Northern blot analysis indicated that they were significantly downregulated in Pst DC3000-infected plants pretreated with AR156, in contrast to the plants without AR156 pretreatment. mi R825 targets two ubiquitin-protein ligases,while mi R825 targets toll-interleukin-like receptor（TIR）-nucleotide binding site（NBS） and leucine-rich repeat（LRR）type resistance（R） genes. The expression of these target genes negatively correlated with the expression of mi R825 and mi R825. Moreover, transgenic plants showing reduced expression of mi R825 and mi R825 displayed enhanced resistance to Pst DC3000 infection, whereas transgenic plants overexpressing mi R825 and mi R825 were more susceptible. Taken together, our data indicates that Bacillus cereus AR156 pretreatment primes ISR to Pst infection by suppressing mi R825 and mi R825 and activating the defense related genes they targeted.展开更多
Three-dimensional graphene foams(GFs)benefit from a large surface area and unique physical properties.We present here the first-ever miniaturized GF-based resonators.We developed a simple yet reliable fabrication proc...Three-dimensional graphene foams(GFs)benefit from a large surface area and unique physical properties.We present here the first-ever miniaturized GF-based resonators.We developed a simple yet reliable fabrication process,in which GFs are synthesized and assembled on a cavity to form suspended GF devices.We electrostatically excited these devices and analyzed their resonance and ring-down responses.We observed significant energy dissipation,as the quality factor of the devices was in the order of several tens.Additionally,we investigated the influence of temperature on the operation of the devices and found that high temperatures mechanically soften the resonators but also considerably enhance energy dissipation.Finally,our devices demonstrated a mode-coupling of a resonance mode and a mode having twice its frequency.Thus,this work paves the way toward the development of novel GF resonators that could be integrated into future devices,such as GF-based nano-electromechanical sensors,electrical circuits,and oscillators.展开更多
基金Research Committee,National Technical University of Athens。
文摘In this study,the design and development of a sensor made of low-cost parts to monitor inclination and acceleration are presented.Αmicro electro-mechanical systems,micro electro mechanical systems,sensor was housed in a robust enclosure and interfaced with a Raspberry Pi microcomputer with Internet connectivity into a proposed tilt and acceleration monitoring node.Online capabilities accessible by mobile phone such as real-time graph,early warning notification,and database logging were implemented using Python programming.The sensor response was calibrated for inherent bias and errors,and then tested thoroughly in the laboratory under static and dynamic loading conditions beside high-quality transducers.Satisfactory accuracy was achieved in real time using the Complementary Filter method,and it was further improved in LabVIEW using Kalman Filters with parameter tuning.A sensor interface with LabVIEW and a 600 MHz CPU microcontroller allowed real-time implementation of highspeed embedded filters,further optimizing sensor results.Kalman and embedded filtering results show agreement for the sensor,followed closely by the lowcomplexity complementary filter applied in real time.The sensor's dynamic response was also verified by shaking table tests,simulating past recorded seismic excitations or artificial vibrations,indicating negligible effect of external acceleration on measured tilt;sensor measurements were benchmarked using highquality tilt and acceleration measuring transducers.A preliminary field evaluation shows robustness of the sensor to harsh weather conditions.
基金National Natural Science Foundation of China (Grant No.11872013) to provide fund for conducting experiments。
文摘The integration method of exploding foil initiator system(EFIs) used to be researched to broaden its application range in military and aerospace in the last few decades.In order to lower the firing voltage below 1 kV,an integrated EFIs with enhanced energy efficiency was designed.Corresponding exploding foil initiator chips were fabricated in batch via micro electromechanical systems technology by integrating a unified foil,a flyer layer and a barrel on a glass substrate successively,meanwhile its package of the whole system was proposed at a volume of 2.194 cm^(3).The structural parameters were determined by predicted performance including flyer velocity,impact behavior and conduction property via the proposed theoretical models and the static electric field simulation.As expect,this integrated EFIs exhibited excellent functions,which could accelerate the flyer to a terminal velocity over 4 km/s and preeminently initiate HNS-IV pellet at a circuit of 0.24 μF/0.9 kV.Furthermore,the theoretical design,fabrication and performance test have been all included to validate the feasibility of this integrated EFIs that was beneficial for its commercial development in the future.
基金supported by National Hi-tech Research and Development Program of China(863 Program,Grant No.2009AA04Z320)Xi’an Municipal Applied Materials Innovation Fund of China(Grant No.XA-AM-200801)
文摘The mode coupling is a major factor to affect the precision of the micro electromechanical systems(MEMS)gyroscope.Currently,many MEMS gyroscopes with separate oscillation modes for drive and detection have been developed to decrease the mode coupling,but the gyroscope accuracy can not satisfy the high-precision demand well.Therefore,high performance decoupled MEMS gyroscopes is still a hot topic at present.An innovative design scheme for a MEMS gyroscope is designed,and in this design,the inertial mass is divided into three parts including the inner mass,the outer mass and the main frame mass.The masses are supported and separated by a set of mutually orthogonal beams to decouple their movements.Moreover,the design is modelled by multi-port-element network(MuPEN)method and the simulation results show that the mode coupling of the gyroscope between driving and sensing mode was eliminated effectively.Furthermore,we proposed a new silicon-on-insulator(SOI)process to fabricate the gyroscope.The scale factor of the fabricated gyroscope is 8.9 mV/((~)os)and the quality factor(Q-factor)is as high as 600 at atmosphere pressure,and then,the resonant frequency,scale factor and bias drift has been test.Process and test results show that the proposed MEMS gyroscope are effective for decrease mode coupling,furthermore,it can achieve a high performance at atmosphere pressure.Furthermore,the MEMS gyroscope can achieve a high performance at atmosphere pressure.The research can be taken as good advice for the design and fabrication of MEMS gyroscope,meanwhile,it also provides technical support for speeding up of MEMS gyroscope industrialization.
文摘A new scheme is proposed to model 3D angular motion of a revolving regular object with miniature, low-cost micro electro mechanical systems(MEMS) accelerometers(instead of gyroscope),which is employed in 3D mouse system.To sense 3D angular motion,the static property of MEMS accelerometer,sensitive to gravity acceleration,is exploited.With the three outputs of configured accelerometers,the proposed model is implemented to get the rotary motion of the rigid object.In order to validate the effectiveness of the proposed model,an input device is developed with the configuration of the scheme.Experimental results show that a simulated 3D cube can accurately track the rotation of the input device.The result indicates the feasibility and effectiveness of the proposed model in the 3D mouse system.
文摘Currently, the monitoring of bridges in China heavily relies on manual operation, which has several major problems. It generally takes a very long time to complete an inspection process on bridges. The manual data is sometimes unreliable or even wrong in the case of careless operation. The inspection activity itself is dangerous for inspectors, e.g., bridges are located in the sea or river. Some semi-automatic monitoring methods are recently employed, but they are either very expensive or do not work properly. Therefore, the traditional bridge monitoring process becomes an increasing challenge for bridge operators. In this paper, a real-time and automatic bridge monitoring system is presented to meet the bridge monitoring needs, and MEMS （Micro Electro Mechanical Systems） are the key building block in this system. By using the MEMS-based sensors, it is much more efficient and accurate in monitoring bridges with the measurement of inclination, acceleration, displacement, moisture, temperature, stress and other data.
文摘The development of personalized healthcare is rapidly growing thanks to the support of low-power electronics,advanced fabrication processes and secured data transmission protocols.Long-acting drug delivery systems able to sustain the release of therapeutics in a controllable manner can provide several advantages in the treatment of chronic diseases.Various systems under development control drug release from an implantable reservoir via concentration driven diffusion through nanofluidic membranes.Given the high drug concentration in the reservoir,an inward osmotic fluid transport occurs across the membrane,which counters the outward diffusion of drugs.The resulting osmotic pressure buildup may be sufficient to cause the failure of implants with associated risks to patients.Confidently assessing the osmotic pressure buildup requires testing in vivo.Here,using metal and polymer AM(additive manufacturing)processes,we designed and developed implantable drug reservoirs with embedded strain sensors to directly measure the osmotic pressure in drug delivery implants in vitro and in vivo.
文摘The last half-century was transformed by the electronic revolution that essentially reproduced the human brain and its computing capacity on a chip. But over time, scientists have realized that something was missing to give life, so to speak, to the small chip with a brain： One needed to awaken its senses and develop its muscles! This challenge was solved through MEMS （micro electro mechanical systems）. Indeed, MEMS today are equipped with the sense of sight, smell, hearing, taste and touch through microsensors. They are also capable of physical exertion through small muscles called microactuators. These new capabilities open wide fields of imagination and important specific applications.
文摘The particles suspending in liquid suffer acoustical radiation force from ultrasonic field. The force may cause particles movement and has special advantage to separate particles from liquid in Micro Electro Mechanical Systems （MEMS）. It is important to improve the energy stored in liquid layer so as to increase separation ability for decreasing drive demand in MEMS. Resonance may hugely increase the magnitude and generally be employed in micro separator. The summits of admittance spectrum show the resonance frequencies. It may come from resonance in one layer or multi layers in micro separator. This paper studies the difference of energy stored in layers at each rein frequency. It provides the way to select the most effect separation frequency other than admittance spectrum.
文摘Wireless communication systems which require flexibility and reconfigurability in antenna systems faces main problems like antenna performance, size, weight and cost. A wide band Frequency Reconfigurable Rectangular Slotted Self Similar Antenna has been proposed in this paper. The rectangular slotted patch is repeated for two iterations at different scales and is separated by means of Radio Frequency Micro Electro Mechanical Systems (RF MEMS) switches in order to provide reconfigurability. The antenna can operate in three frequency bandsi.e. K-band, Ku-band and Ka-band by altering the states of RF MEMS switches. To avoid fringing effects and to improve antenna performance, quarter wavelength (λ/4) spacing is required between the antenna and the ground plane. However, a Reconfigurable Antenna requires different λ/4 spacing which is difficult to achieve using a common ground plane. So the Frequency Reconfigurable antenna is integrated with high impedance surface (HIS) like Electronic Band Gap (EBG) structures to suppress standing waves and surface waves with a unified profile thickness of 1.75 mm. The overall dimension of the proposed antenna along with RF MEMS Switch, feed element and HIS is about 8 mm × 8 mm × 1.75 mm. The simulated results of the proposed antenna reveal enhancement in antennas performance like Voltage Standing Wave Ratio (VSWR), Front to Back Ratio (FBR) and bandwidth when it is placed over HIS EBG. Also the radiation patterns of the proposed antenna when placed over EBG shows the suppression of side lobe and backward radiation.
文摘The concept of micro-total analysis systems(µTAS)introduced in the early 1990s revolutionized the development of lab-on-a-chip(LoC)technologies by miniaturizing and automating complex laboratory processes.Despite their potential in diagnostics,drug development,and environmental monitoring,the widespread adoption of LoC systems has been hindered by challenges in scalability,integration,and cost-effective mass production.Traditional substrates like silicon,glass,and polymers struggle to meet the multifunctional requirements of practical applications.Lab-on-Printed Circuit Board(Lab-on-PCB)technology has emerged as a transformative solution,leveraging the cost-efficiency,scalability,and precision of PCB fabrication techniques.This platform facilitates the seamless integration of microfluidics,sensors,and actuators within a single device,enabling complex,multifunctional systems suitable for real-world deployment.Recent advancements have demonstrated Lab-on-PCB’s versatility across biomedical applications,such as point-of-care diagnostics,electrochemical biosensing,and molecular detection,as well as drug development and environmental monitoring.This review examines the evolution of Lab-on-PCB technology over the past eight years,focusing on its applications and impact within the research community.By analyzing recent progress in PCB-based microfluidics and biosensing,this work highlights how Lab-on-PCB systems address key technical barriers,paving the way for scalable and practical lab-on-chip solutions.The growing academic and industrial interest in Lab-on-PCB is underscored by a notable increase in publications and patents,signaling its potential for commercialization and broader adoption.
基金supported by the National Natural Science Foundation of China(Nos.62074029,61905035,61971108,62004029,51905554)the National Key Research and Development Program of China(No.2022YFB3206100)+3 种基金the Key R&D Program of Sichuan Province(Nos.2022JDTD0020,2020ZHCG0038)the Sichuan Science and Technology Program(Nos.2020JDJQ0036,2019YJ0198,2020YJ0015)the Natural Science Foundation of Sichuan(No.2022NSFSC1941)the Fundamental Research Funds for the Central Universities(No.ZYGX2019Z002).
文摘Transparent conductive films that are based on nanowire networks are essential to construct flexible,wearable,and even stretchable electronics.However,large-scale precise micropatterning,especially with regard to the controllability of the organizing orientation of nanowires,is a critical challenge.Herein,we proposed a liquid film rupture self-assembly approach for manufacturing transparent conductive films with microstructure arrays based on a highly ordered nanowire network.The large-scale microstructure conductive films were fabricated through air-liquid interface self-assembly and liquid film rupture self-assembly.Six typical micropattern morphologies,including square,hexagon,circle,serpentine,etc.,were prepared to reveal the universal applicability of the proposed approach.The homogeneity and controllability of this approach were verified for multiple assemblies.With the assembly cycles increasing,the optical transmittance decreases slightly.In addition,theoretical model analysis is carried out,and the analytical formula of the speed of the film moving with the surface tension and the density of the liquid film is presented.Finally,the feasibility of this approach for piezoresistive strain sensors is verified.This fabrication approach demonstrated a cost-effective and efficient method for precisely arranging nanowires,which is useful in transparent and wearable applications.
基金Supported by Foundation of Department of Mechanical and Electrical Engineering of Xiamen University (No. Y03001)
文摘A new process and technology of rapid prototyping for a μ-micro motor is presented as a nontraditional machining and an advanced manufacturing technology (AMT) to be realized by using masks, including the operation principle of the motor, structure design, technique, driven circuit, and quality examination with Raman spectrum. The μ-micro motor is fabricated by the micro electro-mechanical systems (MEMS) process, the structure design must be considered to fabricate or assembly the parts during machining the motor in the meantime. The research proved that integration of IC (integrated circuit) process and MEMS using masks is effective in obtaining the rapid prototyping manufacturing of the μ-micro motor. With the mature technique to fabricate the motor, there are advantages to produce the motor in short time and with lower cost than before. The motor is a common power source of micro machines in military and civilian applications, for example, applied to micro robot, micro bio medicine, and micro machine. The size of the motor is 190 μm in maximum diameter by 125 μm in height that is bulk machined in array with the number of hundreds of micro motors on a substrate.
基金supported by the National Natural Science Foundation of China(Grant No.90307014).
文摘A novel amperometric immunosensor based on the micro electromechanical systems （MEMS） technology, using protein A and self-assembled monolayers （SAMs） for the orientation-controlled immobilization of antibodies, has been developed. Using MEMS technology, an ＂Au, Pt, Pt＂ three-microelectrode system enclosed in a SU-8 micro pool was fabricated. Employing SAMs, a monolayer of protein A was immobilized on the cysteamine modified Au electrode to achieve the orientation-controlled immobilization of the human immunoglobulin （HIgG） antibody. The immunosensor aimed at low unit cost, small dimension, high level of integration and the prospect of a biosensor system-on-a-chip. Cyclic voltammetry and chronoamperometry were conducted to characterize the immunosensor. Compared with the traditional immunosensor using bulky gold electrode or screen-printed electrode and the procedure directly binding protein A to electrode for immobilization of antibodies, it had attractive advantages, such as miniaturization, compatibility with CMOS technology, fast response （30 s）, broad linear range （50-400 pg/L） and low detection limit （10 pg/L） for HIgG. In addition, this immunosensor was easy to be designed into micro array and to realize the simultaneously multi-parameter detection.
基金supported by a Joint Research Fund for Overseas,Hong Kong and Macao Scholars(31228018)to HJ and JGNIH grant(R01GM093008)to HJ+5 种基金NIH grant-(R01GM100364)a grant from Natural Science Foundation of Jiangsu Province of China(BK20141360)a PhD Programs Foundation of Ministry of Education of China(B0201300664)to HZan National Science Foundation grant(DBI-0743797)to WZa Talent Development Program of Wuhan,the municipal government of Wuhan,Hubei,China(2014070504020241)an internal research grant of Jianghan University,Wuhan,China to WZ
文摘Small RNAs play an important role in plant immune responses. However, their regulatory function in induced systemic resistance（ISR） is nascent. Bacillus cereus AR156 is a plant growth-promoting rhizobacterium that induces ISR in Arabidopsis against bacterial infection. Here,by comparing small RNA profiles of Pseudomonas syringae pv. tomato（Pst） DC3000-infected Arabidopsis with and without AR156 pretreatment, we identified a group of Arabidopsis micro RNAs（mi RNAs） that are differentially regulated by AR156 pretreatment. mi R825 and mi R825 are two mi RNA generated from a single mi RNA gene.Northern blot analysis indicated that they were significantly downregulated in Pst DC3000-infected plants pretreated with AR156, in contrast to the plants without AR156 pretreatment. mi R825 targets two ubiquitin-protein ligases,while mi R825 targets toll-interleukin-like receptor（TIR）-nucleotide binding site（NBS） and leucine-rich repeat（LRR）type resistance（R） genes. The expression of these target genes negatively correlated with the expression of mi R825 and mi R825. Moreover, transgenic plants showing reduced expression of mi R825 and mi R825 displayed enhanced resistance to Pst DC3000 infection, whereas transgenic plants overexpressing mi R825 and mi R825 were more susceptible. Taken together, our data indicates that Bacillus cereus AR156 pretreatment primes ISR to Pst infection by suppressing mi R825 and mi R825 and activating the defense related genes they targeted.
文摘Three-dimensional graphene foams(GFs)benefit from a large surface area and unique physical properties.We present here the first-ever miniaturized GF-based resonators.We developed a simple yet reliable fabrication process,in which GFs are synthesized and assembled on a cavity to form suspended GF devices.We electrostatically excited these devices and analyzed their resonance and ring-down responses.We observed significant energy dissipation,as the quality factor of the devices was in the order of several tens.Additionally,we investigated the influence of temperature on the operation of the devices and found that high temperatures mechanically soften the resonators but also considerably enhance energy dissipation.Finally,our devices demonstrated a mode-coupling of a resonance mode and a mode having twice its frequency.Thus,this work paves the way toward the development of novel GF resonators that could be integrated into future devices,such as GF-based nano-electromechanical sensors,electrical circuits,and oscillators.
