An air parametric array can generate a highly directional beam of audible sound in air,which has a wide range of applications in targeted audio delivery.Capacitive micromachined ultrasonic transducer(CMUTs)have great ...An air parametric array can generate a highly directional beam of audible sound in air,which has a wide range of applications in targeted audio delivery.Capacitive micromachined ultrasonic transducer(CMUTs)have great potential for air-coupled applications,mainly because of their low acoustic impedance.In this study,an air-coupled CMUT array is designed as an air parametric array.A hexagonal array is proposed to improve the directivity of the sound generated.A finite element model of the CMUT is established in COMSOL software to facilitate the choice of appropriate structural parameters of the CMUT cell.The CMUT array is then fabricated by a wafer bonding process with high consistency.The performances of the CMUT are tested to verify the accuracy of the finite element analysis.By optimizing the component parameters of the bias-T circuit used for driving the CMUT,DC and AC voltages can be effectively applied to the top and bottom electrodes of the CMUT to provide efficient ultrasound transmission.Finally,the prepared hexagonal array is successfully used to conduct preliminary experiments on its application as an air parametric array.展开更多
Gravimetric resonant-inspired biosensors have attracted increasing attention in industrial and point-ofcare applications,enabling label-free detection of biomarkers such as DNA and antibodies.Capacitive micromachined ...Gravimetric resonant-inspired biosensors have attracted increasing attention in industrial and point-ofcare applications,enabling label-free detection of biomarkers such as DNA and antibodies.Capacitive micromachined ultrasonic transducers(CMUTs)are promising tools for developing miniaturized highperformance biosensing complementary metal–oxide–silicon(CMOS)platforms.However,their operability is limited by inefficient functionalization,aggregation,crosstalk in the buffer,and the requirement for an external high-voltage(HV)power supply.In this study,we aimed to propose a CMUTs-based resonant biosensor integrated with a CMOS front–end interface coupled with ethylene–glycol alkanethiols to detect single-stranded DNA oligonucleotides with large specificity.The topography of the functionalized surface was characterized by energy-dispersive X-ray microanalysis.Improved selectivity for onchip hybridization was demonstrated by comparing complementary and non-complementary singlestranded DNA oligonucleotides using fluorescence imaging technology.The sensor array was further characterized using a five-element lumped equivalent model.The 4 mm^(2) application-specific integrated circuit chip was designed and developed through 0.18 lm HV bipolar-CMOS-double diffused metal–oxide–silicon(DMOS)technology(BCD)to generate on-chip 20 V HV boosting and to track feedback frequency under a standard 1.8 V supply,with a total power consumption of 3.8 mW in a continuous mode.The measured results indicated a detection sensitivity of 7.943×10^(-3) lmol·L^(-1)·Hz^(-1) over a concentration range of 1 to 100 lmol·L^(-1).In conclusion,the label-free biosensing of DNA under dry conditions was successfully demonstrated using a microfabricated CMUT array with a 2 MHz frequency on CMOS electronics with an internal HV supplier.Moreover,ethylene–glycol alkanethiols successfully deposited self-assembled monolayers on aluminum electrodes,which has never been attempted thus far on CMUTs,to enhance the selectivity of bio-functionalization.The findings of this study indicate the possibility of full-on-chip DNA biosensing with CMUTs.展开更多
Ultrasonic power and data transfer is a promising technology for implantable medical devices because of its non-invasiveness,deep penetration depth,and potential for a high-power transmission rate with a low specific ...Ultrasonic power and data transfer is a promising technology for implantable medical devices because of its non-invasiveness,deep penetration depth,and potential for a high-power transmission rate with a low specific absorption rate.However,ultrasound-powered implantable devices still suffer from low power transfer efficiency due to beam misalignment and are limited to short-term use due to the bulkiness of the transmitting transducers.Here,we report the first proof of concept for adaptive positioning and targeting of ultrasound-based implantable devices through ultrasound image guidance.A lightweight patch-type ultrasonic transducer array is fabricated to enable ultrasound imaging and beam-forming during long-term operation.The uniform performance of the array is established through the silicon micromachining process.We demonstrate the complete scheme of imaging,positioning,and targeted power transfer in an ex vivo environment,achieving precise targeting of moving implanted devices through real-time ultrasound imaging.Enhanced power transfer efficiency through the use of patch-type ultrasonic transducers can enhance patient comfort and minimize invasive procedures,opening new applications for ultrasonic-powered implantable devices.展开更多
The use of bulk piezoelectric transducer arrays in medical imaging is a well-established technology that operates based on thickness mode piezoelectric vibration.Meanwhile,advancements in fabrication techniques have l...The use of bulk piezoelectric transducer arrays in medical imaging is a well-established technology that operates based on thickness mode piezoelectric vibration.Meanwhile,advancements in fabrication techniques have led to the emergence of micromachined alternatives,namely,piezoelectric micromachined ultrasound transducer(PMUT)and capacitive micromachined ultrasound transducer(CMUT).These devices operate in flexural mode using piezoelectric thin films and electrostatic forces,respectively.In addition,the development of flexible ultrasound transducers based on these principles has opened up new possibilities for biomedical applications,including biomedical imaging,sensing,and stimulation.This review provides a detailed discussion of the need for flexible micromachined ultrasound transducers(MUTs)and potential applications,their specifications,materials,fabrication,and electronics integration.Specifically,the review covers fabrication approaches and compares the performance specifications of flexible PMUTs and CMUTs,including resonance frequency,sensitivity,flexibility,and other relevant factors.Finally,the review concludes with an outlook on the challenges and opportunities associated with the realization of efficient MUTs with high performance and flexibility.展开更多
In this paper the cross correlation technique for measuring velocity of bulk material flow in pipe line was investigated and a new capacitance transducer with converter has been introduced. The system was controlled b...In this paper the cross correlation technique for measuring velocity of bulk material flow in pipe line was investigated and a new capacitance transducer with converter has been introduced. The system was controlled by single chip computer with a real-time cross correlation cumputing software. Computing time reaches 1 sec and velocity measuring error is less than 1%.展开更多
This paper describes the design and development of the timer based on liquid level measurement system in which timer 555 is used in astable mode. The capacitor charging time i. e. the ON time pulse width of the ti...This paper describes the design and development of the timer based on liquid level measurement system in which timer 555 is used in astable mode. The capacitor charging time i. e. the ON time pulse width of the timer output waveform which is measured using a digital storage oscillator （DSO）,is linearly proportional to the capacitance of a co-axial cylindrical capacitive transducer, and this capacitance once again linearly varies with the change in liquid level. Hence, we obtain a linear relationship between the liquid level and the capacitor charging time. The main advantages of this developed system are linear input-output relationship, small in size, easily portable, cost effective, and independent on the ambient temperature effect. The system can also be exploited to measure dielectric constant of liquid or solid in various process industries.展开更多
Capacitive micromechanical ultrasonic transducers(CMUTs)have been widely studied because they can be used as substitutes for piezoelectric ultrasonic transducers in imaging applications.However,it is unclear whether a...Capacitive micromechanical ultrasonic transducers(CMUTs)have been widely studied because they can be used as substitutes for piezoelectric ultrasonic transducers in imaging applications.However,it is unclear whether and how CMUTs can be developed for sensors incorporating other functions.For instance,researchers have proposed the use of CMUTs for pressure sensing,but fundamental and practical application issues remain unsolved.This study explored ways in which a pressure sensor can be properly developed based on a CMUT prototype using a simulation approach.A three-dimensional finite element model of CMUTs was designed using the COMSOL Multiphysics software by combining the working principle of CMUTs with pressure sensing characteristics in which the resonance frequency of the CMUT cell shifts accordingly when it is subjected to an external pressure.Simultaneously,when subjected to pressure,the CMUT membrane deforms,thus the pressure can be reflected by the change in the capacitance.展开更多
The method rising measuring resolution through reducing pitch of the transducer has brought forward from the basic structure, principle and the corresponding relationship among pitches of capacitive electrodes, period...The method rising measuring resolution through reducing pitch of the transducer has brought forward from the basic structure, principle and the corresponding relationship among pitches of capacitive electrodes, period T and phase shift of vv(x,t). But if the traditional technique of PCB made of the transducer is still used, it will meet with difficulties in lead wire. And so the technology transplant from the transducer to grating is presented, the basic principle of the phase modulation grating similar...展开更多
基金the National Key R&D Program of China(Nos.2017YFA0205103 and 2018YFE020505)the National Natural Science Foundation of China(Nos.81571766 and 61771337)+1 种基金the Natural Science Foundation of Tianjin,China(No.17JCYBJC24400)the“111”Project of China(No.B07014).
文摘An air parametric array can generate a highly directional beam of audible sound in air,which has a wide range of applications in targeted audio delivery.Capacitive micromachined ultrasonic transducer(CMUTs)have great potential for air-coupled applications,mainly because of their low acoustic impedance.In this study,an air-coupled CMUT array is designed as an air parametric array.A hexagonal array is proposed to improve the directivity of the sound generated.A finite element model of the CMUT is established in COMSOL software to facilitate the choice of appropriate structural parameters of the CMUT cell.The CMUT array is then fabricated by a wafer bonding process with high consistency.The performances of the CMUT are tested to verify the accuracy of the finite element analysis.By optimizing the component parameters of the bias-T circuit used for driving the CMUT,DC and AC voltages can be effectively applied to the top and bottom electrodes of the CMUT to provide efficient ultrasound transmission.Finally,the prepared hexagonal array is successfully used to conduct preliminary experiments on its application as an air parametric array.
基金supported by the National Key Research and Development Program of China(2022YFB3205400)the National Natural Science Foundation of China(52275570)+1 种基金the Postdoctoral Innovation Talents Support Program(BX20230288)the Postdoctoral Science Foundation of Shaanxi Province(2018BSHEDZZ08).
文摘Gravimetric resonant-inspired biosensors have attracted increasing attention in industrial and point-ofcare applications,enabling label-free detection of biomarkers such as DNA and antibodies.Capacitive micromachined ultrasonic transducers(CMUTs)are promising tools for developing miniaturized highperformance biosensing complementary metal–oxide–silicon(CMOS)platforms.However,their operability is limited by inefficient functionalization,aggregation,crosstalk in the buffer,and the requirement for an external high-voltage(HV)power supply.In this study,we aimed to propose a CMUTs-based resonant biosensor integrated with a CMOS front–end interface coupled with ethylene–glycol alkanethiols to detect single-stranded DNA oligonucleotides with large specificity.The topography of the functionalized surface was characterized by energy-dispersive X-ray microanalysis.Improved selectivity for onchip hybridization was demonstrated by comparing complementary and non-complementary singlestranded DNA oligonucleotides using fluorescence imaging technology.The sensor array was further characterized using a five-element lumped equivalent model.The 4 mm^(2) application-specific integrated circuit chip was designed and developed through 0.18 lm HV bipolar-CMOS-double diffused metal–oxide–silicon(DMOS)technology(BCD)to generate on-chip 20 V HV boosting and to track feedback frequency under a standard 1.8 V supply,with a total power consumption of 3.8 mW in a continuous mode.The measured results indicated a detection sensitivity of 7.943×10^(-3) lmol·L^(-1)·Hz^(-1) over a concentration range of 1 to 100 lmol·L^(-1).In conclusion,the label-free biosensing of DNA under dry conditions was successfully demonstrated using a microfabricated CMUT array with a 2 MHz frequency on CMOS electronics with an internal HV supplier.Moreover,ethylene–glycol alkanethiols successfully deposited self-assembled monolayers on aluminum electrodes,which has never been attempted thus far on CMUTs,to enhance the selectivity of bio-functionalization.The findings of this study indicate the possibility of full-on-chip DNA biosensing with CMUTs.
基金supported by the Korea Medical Device Development Fund grant funded by the Korea government(the Ministry of Science and ICT,the Ministry of Trade,Industry and Energy,the Ministry of Health&Welfare,Republic of Korea,the Ministry of Food and Drug Safety)(202011B01,RS-2020-KD000007)by the K-Brain Project of the National Research Foundation(NRF)funded by the Korean government(MSIT)(RS-2023-00262568)+3 种基金by a grant of the Korea Dementia Research Project through the Korea Dementia Research Center(KDRC)funded by the Ministry of Health&Welfare and Ministry of Science and ICT,Republic of Korea(RS-2024-00355871)by Nanomedical Devices Development Project of NNFC(1711197701)by Samsung Electronics.
文摘Ultrasonic power and data transfer is a promising technology for implantable medical devices because of its non-invasiveness,deep penetration depth,and potential for a high-power transmission rate with a low specific absorption rate.However,ultrasound-powered implantable devices still suffer from low power transfer efficiency due to beam misalignment and are limited to short-term use due to the bulkiness of the transmitting transducers.Here,we report the first proof of concept for adaptive positioning and targeting of ultrasound-based implantable devices through ultrasound image guidance.A lightweight patch-type ultrasonic transducer array is fabricated to enable ultrasound imaging and beam-forming during long-term operation.The uniform performance of the array is established through the silicon micromachining process.We demonstrate the complete scheme of imaging,positioning,and targeted power transfer in an ex vivo environment,achieving precise targeting of moving implanted devices through real-time ultrasound imaging.Enhanced power transfer efficiency through the use of patch-type ultrasonic transducers can enhance patient comfort and minimize invasive procedures,opening new applications for ultrasonic-powered implantable devices.
基金supported by EU EIC Transition under grant agreement ID 101057902,as well as KU Leuven Interdisciplinary Networks(ID-N)under grant No.ZKD-6578。
文摘The use of bulk piezoelectric transducer arrays in medical imaging is a well-established technology that operates based on thickness mode piezoelectric vibration.Meanwhile,advancements in fabrication techniques have led to the emergence of micromachined alternatives,namely,piezoelectric micromachined ultrasound transducer(PMUT)and capacitive micromachined ultrasound transducer(CMUT).These devices operate in flexural mode using piezoelectric thin films and electrostatic forces,respectively.In addition,the development of flexible ultrasound transducers based on these principles has opened up new possibilities for biomedical applications,including biomedical imaging,sensing,and stimulation.This review provides a detailed discussion of the need for flexible micromachined ultrasound transducers(MUTs)and potential applications,their specifications,materials,fabrication,and electronics integration.Specifically,the review covers fabrication approaches and compares the performance specifications of flexible PMUTs and CMUTs,including resonance frequency,sensitivity,flexibility,and other relevant factors.Finally,the review concludes with an outlook on the challenges and opportunities associated with the realization of efficient MUTs with high performance and flexibility.
基金This project is supported by the doctorate fund of State Education Commission
文摘In this paper the cross correlation technique for measuring velocity of bulk material flow in pipe line was investigated and a new capacitance transducer with converter has been introduced. The system was controlled by single chip computer with a real-time cross correlation cumputing software. Computing time reaches 1 sec and velocity measuring error is less than 1%.
文摘This paper describes the design and development of the timer based on liquid level measurement system in which timer 555 is used in astable mode. The capacitor charging time i. e. the ON time pulse width of the timer output waveform which is measured using a digital storage oscillator （DSO）,is linearly proportional to the capacitance of a co-axial cylindrical capacitive transducer, and this capacitance once again linearly varies with the change in liquid level. Hence, we obtain a linear relationship between the liquid level and the capacitor charging time. The main advantages of this developed system are linear input-output relationship, small in size, easily portable, cost effective, and independent on the ambient temperature effect. The system can also be exploited to measure dielectric constant of liquid or solid in various process industries.
文摘Capacitive micromechanical ultrasonic transducers(CMUTs)have been widely studied because they can be used as substitutes for piezoelectric ultrasonic transducers in imaging applications.However,it is unclear whether and how CMUTs can be developed for sensors incorporating other functions.For instance,researchers have proposed the use of CMUTs for pressure sensing,but fundamental and practical application issues remain unsolved.This study explored ways in which a pressure sensor can be properly developed based on a CMUT prototype using a simulation approach.A three-dimensional finite element model of CMUTs was designed using the COMSOL Multiphysics software by combining the working principle of CMUTs with pressure sensing characteristics in which the resonance frequency of the CMUT cell shifts accordingly when it is subjected to an external pressure.Simultaneously,when subjected to pressure,the CMUT membrane deforms,thus the pressure can be reflected by the change in the capacitance.
文摘The method rising measuring resolution through reducing pitch of the transducer has brought forward from the basic structure, principle and the corresponding relationship among pitches of capacitive electrodes, period T and phase shift of vv(x,t). But if the traditional technique of PCB made of the transducer is still used, it will meet with difficulties in lead wire. And so the technology transplant from the transducer to grating is presented, the basic principle of the phase modulation grating similar...
