We present the fabrication and testing of a silicon carbide （SiC） balanced mass doublended tuning fork that survives harsh environments without compromising the device strain sensitivity and resolution bandwidth. Th...We present the fabrication and testing of a silicon carbide （SiC） balanced mass doublended tuning fork that survives harsh environments without compromising the device strain sensitivity and resolution bandwidth. The device features a material stack that survives corrosive environments and enables high-temperature operation. To perform hightemperature testing, a specialized setup was constructed that allows the tuning fork to be characterized using traditional silicon electronics. The tuning fork has been operated at 600°C in the presence of dry steam for short durations. This tuning fork has also been tested to 64 000 G using a hard-launch, soft-catch shock implemented with a light gas gun. However, the device still has a strain sensitivity of 66 Hz/μe and strain resolution of 0. 045 μe in a 10 kHz bandwidth. As such, this balanced-mass double-ended tuning fork can be used to create a variety of different sensors including strain gauges, accelerometers, gyroscopes, and pressure transducers. Given the adaptable fabrication process flow, this device could be useful to micro-electro-mechanical systems （MEMS） designers creating sensors for a variety of different applications.展开更多
Three-dimensional(3D)additive manufacturing techniques have been utilized to make 3D electrical components,such as resistors,capacitors,and inductors,as well as circuits and passive wireless sensors.Using the fused de...Three-dimensional(3D)additive manufacturing techniques have been utilized to make 3D electrical components,such as resistors,capacitors,and inductors,as well as circuits and passive wireless sensors.Using the fused deposition modeling technology and a multiple-nozzle system with a printing resolution of 30μm,3D structures with both supporting and sacrificial structures are constructed.After removing the sacrificial materials,suspensions with silver particles are injected subsequently solidified to form metallic elements/interconnects.The prototype results show good characteristics of fabricated 3D microelectronics components,including an inductor–capacitor-resonant tank circuitry with a resonance frequency at 0.53 GHz.A 3D“smart cap”with an embedded inductor–capacitor tank as the wireless passive sensor was demonstrated to monitor the quality of liquid food(e.g.,milk and juice)wirelessly.The result shows a 4.3%resonance frequency shift from milk stored in the room temperature environment for 36 h.This work establishes an innovative approach to construct arbitrary 3D systems with embedded electrical structures as integrated circuitry for various applications,including the demonstrated passive wireless sensors.展开更多
The recent developments in material sciences and rational structural designs have advanced the field of compliant and deformable electronics systems.However,many of these systems are limited in either overall stretcha...The recent developments in material sciences and rational structural designs have advanced the field of compliant and deformable electronics systems.However,many of these systems are limited in either overall stretchability or areal coverage of functional components.Here,we design a construct inspired by Kirigami for highly deformable microsupercapacitor patches with high areal coverages of electrode and electrolyte materials.These patches can be fabricated in simple and efficient steps by laser-assisted graphitic conversion and cutting.Because the Kirigami cuts significantly increase structural compliance,segments in the patches can buckle,rotate,bend and twist to accommodate large overall deformations with only a small strain(<3%)in active electrode areas.Electrochemical testing results have proved that electrical and electrochemical performances are preserved under large deformation,with less than 2%change in capacitance when the patch is elongated to 382.5%of its initial length.The high design flexibility can enable various types of electrical connections among an array of supercapacitors residing in one patch,by using different Kirigami designs.展开更多
Materials and device architecture innovations are essential for further enhancing the performance of solar cells while potentially enabling their large-scale integration as a viable source of alternative energy.In thi...Materials and device architecture innovations are essential for further enhancing the performance of solar cells while potentially enabling their large-scale integration as a viable source of alternative energy.In this regard,tremendous research has been devoted in recent years with continuous progress in the field.In this article,we review the recent advancements in nanopillar-based photovoltaics while discussing the future challenges and prospects.Nanopillar arrays provide unique advantages over thin films in the areas of optical properties and carrier collection,arising from their three-dimensional geometry.The choice of the material system,however,is essential in order to gain the advantage of the large surface/interface area associated with nanopillars with the constraints different from those of the thin film devices.展开更多
Nucleic acid amplification and quantification via polymerase chain reaction(PCR)is one of the most sensitive and powerful tools for clinical laboratories,precision medicine,personalized medicine,agricultural science,f...Nucleic acid amplification and quantification via polymerase chain reaction(PCR)is one of the most sensitive and powerful tools for clinical laboratories,precision medicine,personalized medicine,agricultural science,forensic science and environmental science.Ultrafast multiplex PCR,characterized by low power consumption,compact size and simple operation,is ideal for timely diagnosis at the point-of-care(POC).Although several fast/ultrafast PCR methods have been proposed,the use of a simple and robust PCR thermal cycler remains challenging for POC testing.Here,we present an ultrafast photonic PCR method using plasmonic photothermal light-to-heat conversion via photon–electron–phonon coupling.We demonstrate an efficient photonic heat converter using a thin gold(Au)film due to its plasmon-assisted high optical absorption(approximately 65%at 450 nm,the peak wavelength of heat source light-emitting diodes(LEDs)).The plasmon-excited Au film is capable of rapidly heating the surrounding solution to over 150℃ within 3 min.Using this method,ultrafast thermal cycling(30 cycles;heating and cooling rate of 12.7960.93℃ s^(-1) and 6.660.29℃ s^(-1),respectively)from 55℃(temperature of annealing)to 95℃(temperature of denaturation)is accomplished within 5 min.Using photonic PCR thermal cycles,we demonstrate here successful nucleic acid(λ-DNA)amplification.Our simple,robust and low cost approach to ultrafast PCR using an efficient photonic-based heating procedure could be generally integrated into a variety of devices or procedures,including on-chip thermal lysis and heating for isothermal amplifications.展开更多
Electrohydrodynamic(EHD)3D printing of ca rbon-based materials in the form of orderly networks can have various applications.In this work,microscale carbon/nickel(C-Ni)composite electrodes with controlled porosity hav...Electrohydrodynamic(EHD)3D printing of ca rbon-based materials in the form of orderly networks can have various applications.In this work,microscale carbon/nickel(C-Ni)composite electrodes with controlled porosity have been utilized in electrochemical energy storage of supercapacitors.Polyacrylonitrile(PAN)was chosen as the basic material for its excellent carbonization performance and EHD printing property.Nickel nitrate(Ni(NO_(3))_(2))was incorporated to form Ni nanoparticles which can improve the conductivity and the capacitance performance of the electrode.Well-aligned PAN-Ni(NO_(3))_(2) composite structures have been fabricated and carbonized as C-Ni electrodes with the typical diameter of 9.2±2.1μm.The porosity of the as-prepared C-Ni electrode can be controlled during the EHD process.Electrochemical results show the C-Ni network electrode has achieved a 2.3 times higher areal specific capacitance and 1.7 times higher mass specific capacitance than those of a spin-coated electrode.As such,this process offers a facile and scalable strategy for the fabrication of orderly carbon-based conductive structures for various applications such as energy storage devices and printable electronics.展开更多
A rapid,precise method for identifying waterborne pathogens is critically needed for effective disinfection and better treatment.However,conventional methods,such as culture-based counting,generally suffer from slow d...A rapid,precise method for identifying waterborne pathogens is critically needed for effective disinfection and better treatment.However,conventional methods,such as culture-based counting,generally suffer from slow detection times and low sensitivities.Here,we developed a rapid detection method for tracing waterborne pathogens by an innovative optofluidic platform,a plasmonic bacteria on a nanoporous mirror,that allows effective hydrodynamic cell trapping,enrichment of pathogens,and optical signal amplifications.We designed and simulated the integrated optofluidic platform to maximize the enrichment of the bacteria and to align bacteria on the nanopores and plasmonic mirror via hydrodynamic cell trapping.Gold nanoparticles are self-assembled to form antenna arrays on the surface of bacteria,such as Escherichia coli and Pseudomonas aeruginosa,by replacing citrate with hydroxylamine hydrochloride in order to amplify the signal of the plasmonic optical array.Owing to the synergistic contributions of focused light via the nanopore geometry,self-assembled nanoplasmonic optical antennas on the surface of bacteria,and plasmonic mirror,we obtain a sensitivity of detecting E.coli as low as 102 cells/ml via surface-enhanced Raman spectroscopy.We believe that our label-free strategy via an integrated optofluidic platform will pave the way for the rapid,precise identification of various pathogens.展开更多
Microfluidic concentration gradient generators(µ-CGGs)have been utilized to identify optimal drug compositions through antimicrobial susceptibility testing(AST)for the treatment of antimicrobial-resistant(AMR)inf...Microfluidic concentration gradient generators(µ-CGGs)have been utilized to identify optimal drug compositions through antimicrobial susceptibility testing(AST)for the treatment of antimicrobial-resistant(AMR)infections.Conventionalµ-CGGs fabricated via photolithography-based micromachining processes,however,are fundamentally limited to two-dimensional fluidic routing,such that only two distinct antimicrobial drugs can be tested at once.This work addresses this limitation by employing Multijet-3D-printed microchannel networks capable of fluidic routing in three dimensions to generate symmetric multidrug concentration gradients.The three-fluid gradient generation characteristics of the fabricated 3Dµ-CGG prototype were quantified through both theoretical simulations and experimental validations.Furthermore,the antimicrobial effects of three highly clinically relevant antibiotic drugs,tetracycline,ciprofloxacin,and amikacin,were evaluated via experimental single-antibiotic minimum inhibitory concentration(MIC)and pairwise and three-way antibiotic combination drug screening(CDS)studies against model antibiotic-resistant Escherichia coli bacteria.As such,this 3Dµ-CGG platform has great potential to enable expedited combination AST screening for various biomedical and diagnostic applications.展开更多
The ability to capture the chemical signatures of biomolecules(i.e.,electron-transfer dynamics)in living cells will provide an entirely new perspective on biology and medicine.This can be accomplished using nanoscale ...The ability to capture the chemical signatures of biomolecules(i.e.,electron-transfer dynamics)in living cells will provide an entirely new perspective on biology and medicine.This can be accomplished using nanoscale optical antennas that can collect,resonate and focus light from outside the cell and emit molecular spectra.Here,we describe biologically inspired nanoscale optical antennas that utilize the unique topologies of plant viruses(and thus,are called gold plant viruses)for molecular fingerprint detection.Our electromagnetic calculations for these gold viruses indicate that capsid morphologies permit high amplification of optical scattering energy compared to a smooth nanosphere.From experimental measurements of various gold viruses based on four different plant viruses,we observe highly enhanced optical cross-sections and the modulation of the resonance wavelength depending on the viral morphology.Additionally,in label-free molecular imaging,we successfully obtain higher sensitivity(by a factor of up to 10^(6))than can be achieved using similar-sized nanospheres.By virtue of the inherent functionalities of capsids and the plasmonic characteristics of the gold layer,a gold virus-based antenna will enable cellular targeting,imaging and drug delivery.展开更多
文摘We present the fabrication and testing of a silicon carbide （SiC） balanced mass doublended tuning fork that survives harsh environments without compromising the device strain sensitivity and resolution bandwidth. The device features a material stack that survives corrosive environments and enables high-temperature operation. To perform hightemperature testing, a specialized setup was constructed that allows the tuning fork to be characterized using traditional silicon electronics. The tuning fork has been operated at 600°C in the presence of dry steam for short durations. This tuning fork has also been tested to 64 000 G using a hard-launch, soft-catch shock implemented with a light gas gun. However, the device still has a strain sensitivity of 66 Hz/μe and strain resolution of 0. 045 μe in a 10 kHz bandwidth. As such, this balanced-mass double-ended tuning fork can be used to create a variety of different sensors including strain gauges, accelerometers, gyroscopes, and pressure transducers. Given the adaptable fabrication process flow, this device could be useful to micro-electro-mechanical systems （MEMS） designers creating sensors for a variety of different applications.
基金Mr.Sung-Yueh Wu is supported by the“Ministry of Science and Technology of Taiwan”(Grant No.103-2917-I-009-192).
文摘Three-dimensional(3D)additive manufacturing techniques have been utilized to make 3D electrical components,such as resistors,capacitors,and inductors,as well as circuits and passive wireless sensors.Using the fused deposition modeling technology and a multiple-nozzle system with a printing resolution of 30μm,3D structures with both supporting and sacrificial structures are constructed.After removing the sacrificial materials,suspensions with silver particles are injected subsequently solidified to form metallic elements/interconnects.The prototype results show good characteristics of fabricated 3D microelectronics components,including an inductor–capacitor-resonant tank circuitry with a resonance frequency at 0.53 GHz.A 3D“smart cap”with an embedded inductor–capacitor tank as the wireless passive sensor was demonstrated to monitor the quality of liquid food(e.g.,milk and juice)wirelessly.The result shows a 4.3%resonance frequency shift from milk stored in the room temperature environment for 36 h.This work establishes an innovative approach to construct arbitrary 3D systems with embedded electrical structures as integrated circuitry for various applications,including the demonstrated passive wireless sensors.
基金This work is supported in part by Berkeley Sensor and Actuator Center.
文摘The recent developments in material sciences and rational structural designs have advanced the field of compliant and deformable electronics systems.However,many of these systems are limited in either overall stretchability or areal coverage of functional components.Here,we design a construct inspired by Kirigami for highly deformable microsupercapacitor patches with high areal coverages of electrode and electrolyte materials.These patches can be fabricated in simple and efficient steps by laser-assisted graphitic conversion and cutting.Because the Kirigami cuts significantly increase structural compliance,segments in the patches can buckle,rotate,bend and twist to accommodate large overall deformations with only a small strain(<3%)in active electrode areas.Electrochemical testing results have proved that electrical and electrochemical performances are preserved under large deformation,with less than 2%change in capacitance when the patch is elongated to 382.5%of its initial length.The high design flexibility can enable various types of electrical connections among an array of supercapacitors residing in one patch,by using different Kirigami designs.
文摘Materials and device architecture innovations are essential for further enhancing the performance of solar cells while potentially enabling their large-scale integration as a viable source of alternative energy.In this regard,tremendous research has been devoted in recent years with continuous progress in the field.In this article,we review the recent advancements in nanopillar-based photovoltaics while discussing the future challenges and prospects.Nanopillar arrays provide unique advantages over thin films in the areas of optical properties and carrier collection,arising from their three-dimensional geometry.The choice of the material system,however,is essential in order to gain the advantage of the large surface/interface area associated with nanopillars with the constraints different from those of the thin film devices.
基金This work was supported in part by a grant from the Bill&Melinda Gates Foundation(Global Health Grant:OPP1028785)in part by the Global Research Lab Program(2013-050616)through the National Research Foundation of Korea funded by the Ministry of Science,ICT(Information and Communication Technologies)and Future Planning.
文摘Nucleic acid amplification and quantification via polymerase chain reaction(PCR)is one of the most sensitive and powerful tools for clinical laboratories,precision medicine,personalized medicine,agricultural science,forensic science and environmental science.Ultrafast multiplex PCR,characterized by low power consumption,compact size and simple operation,is ideal for timely diagnosis at the point-of-care(POC).Although several fast/ultrafast PCR methods have been proposed,the use of a simple and robust PCR thermal cycler remains challenging for POC testing.Here,we present an ultrafast photonic PCR method using plasmonic photothermal light-to-heat conversion via photon–electron–phonon coupling.We demonstrate an efficient photonic heat converter using a thin gold(Au)film due to its plasmon-assisted high optical absorption(approximately 65%at 450 nm,the peak wavelength of heat source light-emitting diodes(LEDs)).The plasmon-excited Au film is capable of rapidly heating the surrounding solution to over 150℃ within 3 min.Using this method,ultrafast thermal cycling(30 cycles;heating and cooling rate of 12.7960.93℃ s^(-1) and 6.660.29℃ s^(-1),respectively)from 55℃(temperature of annealing)to 95℃(temperature of denaturation)is accomplished within 5 min.Using photonic PCR thermal cycles,we demonstrate here successful nucleic acid(λ-DNA)amplification.Our simple,robust and low cost approach to ultrafast PCR using an efficient photonic-based heating procedure could be generally integrated into a variety of devices or procedures,including on-chip thermal lysis and heating for isothermal amplifications.
基金supported in part by Berkeley Sensor and Actuator Center&Berkeley Biomolecular Nanotechnology Centerfinancially supported by the National Key Research and Design Program of China(No.2018YFA0703000)+3 种基金the National Natural Science Foundation of China(Nos.51675412,51422508)the Key Research Project of Shaanxi Province(No.2020GXLH-Y-021)The Youth Innovation Team of Shaanxi Universities and the Fundamental Research Funds for the Central Universitiesfinancial support from China Scholarship Council。
文摘Electrohydrodynamic(EHD)3D printing of ca rbon-based materials in the form of orderly networks can have various applications.In this work,microscale carbon/nickel(C-Ni)composite electrodes with controlled porosity have been utilized in electrochemical energy storage of supercapacitors.Polyacrylonitrile(PAN)was chosen as the basic material for its excellent carbonization performance and EHD printing property.Nickel nitrate(Ni(NO_(3))_(2))was incorporated to form Ni nanoparticles which can improve the conductivity and the capacitance performance of the electrode.Well-aligned PAN-Ni(NO_(3))_(2) composite structures have been fabricated and carbonized as C-Ni electrodes with the typical diameter of 9.2±2.1μm.The porosity of the as-prepared C-Ni electrode can be controlled during the EHD process.Electrochemical results show the C-Ni network electrode has achieved a 2.3 times higher areal specific capacitance and 1.7 times higher mass specific capacitance than those of a spin-coated electrode.As such,this process offers a facile and scalable strategy for the fabrication of orderly carbon-based conductive structures for various applications such as energy storage devices and printable electronics.
基金supported by the Air Force Office of Scientific Research Grants AFOSR FA2386-13-1-4120by the International Research and Development Program of the National Research Foundation of Korea(NRF)+5 种基金by the Ministry of Science,ICT,and Future Planning(MSIP)(no.2016K1A3A1A32913356)by the Mid-Career Researcher Support Program of NRF by the MSIP(no.2016R1A2B3014157)by the Basic Science Research Program through the NRF funded by the Ministry of Education(no.2016R1A6A1A03012845)by the C1 Gas Refinery Program of NRF by the MSIP(no.2016M3D3A1A01913546)by the Leading Foreign Research Institute Recruitment Program through NRF by the MSIP(no.2013K1A4A3055268)by the National Institutes of Health(NIH)(R01 AI117064-01).
文摘A rapid,precise method for identifying waterborne pathogens is critically needed for effective disinfection and better treatment.However,conventional methods,such as culture-based counting,generally suffer from slow detection times and low sensitivities.Here,we developed a rapid detection method for tracing waterborne pathogens by an innovative optofluidic platform,a plasmonic bacteria on a nanoporous mirror,that allows effective hydrodynamic cell trapping,enrichment of pathogens,and optical signal amplifications.We designed and simulated the integrated optofluidic platform to maximize the enrichment of the bacteria and to align bacteria on the nanopores and plasmonic mirror via hydrodynamic cell trapping.Gold nanoparticles are self-assembled to form antenna arrays on the surface of bacteria,such as Escherichia coli and Pseudomonas aeruginosa,by replacing citrate with hydroxylamine hydrochloride in order to amplify the signal of the plasmonic optical array.Owing to the synergistic contributions of focused light via the nanopore geometry,self-assembled nanoplasmonic optical antennas on the surface of bacteria,and plasmonic mirror,we obtain a sensitivity of detecting E.coli as low as 102 cells/ml via surface-enhanced Raman spectroscopy.We believe that our label-free strategy via an integrated optofluidic platform will pave the way for the rapid,precise identification of various pathogens.
基金This project was funded through the Berkeley Sensors and Actuators Center(BSAC)at UC Berkeley.
文摘Microfluidic concentration gradient generators(µ-CGGs)have been utilized to identify optimal drug compositions through antimicrobial susceptibility testing(AST)for the treatment of antimicrobial-resistant(AMR)infections.Conventionalµ-CGGs fabricated via photolithography-based micromachining processes,however,are fundamentally limited to two-dimensional fluidic routing,such that only two distinct antimicrobial drugs can be tested at once.This work addresses this limitation by employing Multijet-3D-printed microchannel networks capable of fluidic routing in three dimensions to generate symmetric multidrug concentration gradients.The three-fluid gradient generation characteristics of the fabricated 3Dµ-CGG prototype were quantified through both theoretical simulations and experimental validations.Furthermore,the antimicrobial effects of three highly clinically relevant antibiotic drugs,tetracycline,ciprofloxacin,and amikacin,were evaluated via experimental single-antibiotic minimum inhibitory concentration(MIC)and pairwise and three-way antibiotic combination drug screening(CDS)studies against model antibiotic-resistant Escherichia coli bacteria.As such,this 3Dµ-CGG platform has great potential to enable expedited combination AST screening for various biomedical and diagnostic applications.
基金This work was supported by the Air Force Office of Scientific Research Grants AFOSR FA2386-13-1-4120.
文摘The ability to capture the chemical signatures of biomolecules(i.e.,electron-transfer dynamics)in living cells will provide an entirely new perspective on biology and medicine.This can be accomplished using nanoscale optical antennas that can collect,resonate and focus light from outside the cell and emit molecular spectra.Here,we describe biologically inspired nanoscale optical antennas that utilize the unique topologies of plant viruses(and thus,are called gold plant viruses)for molecular fingerprint detection.Our electromagnetic calculations for these gold viruses indicate that capsid morphologies permit high amplification of optical scattering energy compared to a smooth nanosphere.From experimental measurements of various gold viruses based on four different plant viruses,we observe highly enhanced optical cross-sections and the modulation of the resonance wavelength depending on the viral morphology.Additionally,in label-free molecular imaging,we successfully obtain higher sensitivity(by a factor of up to 10^(6))than can be achieved using similar-sized nanospheres.By virtue of the inherent functionalities of capsids and the plasmonic characteristics of the gold layer,a gold virus-based antenna will enable cellular targeting,imaging and drug delivery.
