检索结果-南通市图书馆

High Precision Temperature Measurement for microfluidic Chip Applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Shanghai Jiaotong university(science) 2022年第5期27卷 699-705页

作者：熊越夫吴校生曾照丰黄山陈天培 National Key Laboratory of Science and Technology on Micro/Nano Fabrication Department of Micro/Nano ElectronicsShanghai Jiao Tong UniversityShanghai200240China

Biochemical reaction in microfluidic chip is sensitive to temperature.Temperature precise control in a small size device requires the temperature measurement with high measurement precision.Traditional temperature measurement method usually measures the voltage drop of the thermistor,which is excited by a constant current source.This method requires the constant current source with high precision and stability.The output of the constant current source is influenced by environmental factors,resulting in a larger measurement error.To solve this problem,a proportion method,a two-layer filtering algorithm,and a power management technique were applied to improve the temperature measurement precision.The proportion method can reduce the low frequency fluctuation error.The two-layer filtering algorithm can reduce the high frequency fluctuation error furtherly.The power management technique used can improve the system stability.Through testing the temperature measurement system built,the experimental results show that the fluctuation error can be significantly decreased from 0.5◦C to 0.2◦C.

关键词： microfluidic chip temperature measurement proportion method two-layer filtering algorithm fluctuation error

SiC nanowire-based SU-8 with enhanced mechanical properties for MEMS structural layer design

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

nanotechnology and Precision Engineering 2019年第4期2卷 169-176页

作者： Yu Yang Liyan Lai Guifu Ding Ting Chen National Key Laboratory of Science and Technology on Micro/Nano Fabrication Shanghai Jiao Tong University

In addition to being used for pattern transfer,the negative photoresist SU-8 iswidely used as a structural material in microelectromechanical systems(MEMS).Due to its good photopatternability,SU-8 has lower manufacturing costs than many other materials,but its mechanical properties are relatively weak to some extent,which limits its performance.The mechanical properties of epoxy-like SU-8 can be enhanced by addingmicro-or nano-fillers such as carbon nanotube,clay,and SiC nanowire,which have superior elastic modulus.In this study,SiC nanowires were used to improve the mechanical properties of SU-8 while the SU-8 retains its photopatternability.The SiC nanowires were uniformly dispersed in SU-8 by stirring and ultrasonication.SU-8 materials with different SiC nanowire contents were fabricated into dog bone samples by lithography.The elastic modulus,storage modulus,and damping factor of the samples were measured by the Dynamic mechanical analysis(DMA)Q800.The experiment result shows that the rigidity and toughness increased,and the damping reduced.The 2 wt%SiC nanowires-reinforced SU-8 had a 73.88%increase in elastic modulus and a 103.4%increase in elongation at break.Furthermore,a spring component made by SiC-doped SU-8 could withstand greater acceleration.The SiC nanowires-reinforced SU-8 has the potential tomeet higher requirements in the design andmanufacture of MEMS and greatly reduce the manufacturing costs of MEMS devices.

关键词： SU-8 SiC nanowires Elastic modulus Dynamic mechanical analysis(DMA)

Manipulating fluid with vibrating 3D-printed paddles for applications in micropump

在线全文

学校读者我要写书评

暂无评论

nanotechnology and Precision Engineering 2019年第3期2卷 95-104页

作者： Zhiyong Tang Xiufeng Shao Jianze Huang Jinyuan Yao Guifu Ding National Key Laboratory of Science and Technology on Micro/Nano Fabrication Shanghai Jiao Tong University

This paper presents a novel working mechanism of a micropump using micropaddles(MPs)to actively manipulate fluid based on 3 D printing technology.The novel working principle is systematically discussed using analysis,computation and experiment methods.A theoretical model is established to research the working mechanism and crucial parameters for driving ability,such as MPs shape,size,vibration amplitude and frequency.Two different 3 D printing techniques that simplify the multi-step process into only one step are introduced to manufacture the prototype pump for investigating the principle experimentally.A testing system is designed to evaluate the flow rate of pumps with eight different vibrating paddles.A maximum flux of 127.9 mL/min is obtained at an applied voltage of 9 V.These experiments show that the active-type mechanical pump could not only freely control flow direction but also change flux by adopting different shapes or distribution ways.The advantage of the novel micropump is the application of the MP structure into the micropump system to actively manipulate fluid with flexibility and high driving ability at fairly low power.

关键词： micropump Manipulate fluid Vibrating micropaddles 3D printing Fluid-structure interaction

Inkjet printing-based fabrication of microscale 3D ice structures

在线全文

学校读者我要写书评

暂无评论

microsystems & nanoengineering 2020年第1期6卷 305-314页

作者： Fengyi Zheng Zhongyan Wang Jiasheng Huang Zhihong Li National Key Laboratory of Science and Technology on Micro/Nano Fabrication Institute of MicroelectronicsPeking UniversityBeijing 100871China

This study proposed a method for fabricating 3D microstructures of ice without a supporting material.The inkjet printing process was performed in a low humidity environment to precisely control the growth direction of the ice crystals.In the printing process,water droplets(volume=hundreds of picoliters)were deposited onto the previously formed ice structure,after which they immediately froze.Different 3D structures(maximum height=2000µm)could be formed by controlling the substrate temperature,ejection frequency and droplet size.The growth direction was dependent on the landing point of the droplet on the previously formed ice structure;thus,3D structures could be created with high degrees of freedom.

关键词： printing structures hundreds

A low-noise high-linearity interface ASIC for MEMS gyroscopes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Semiconductors 2013年第12期34卷 109-114页

作者：方然鲁文高王冠男陶婷婷张雅聪陈中建于敦山 National Key Laboratory of Science and Technology on Micro/Nano Fabrication Peking University

This paper presents a continuous-time analog interface ASIC for use in MEMS gyroscopes. A charge sensitive amplifier with a chopper stabilization method is adopted to suppress the low-frequency noise. In order to cancel the effect caused by the gyroscope capacitive mismatch, a mismatch auto-compensation circuit is imple- mented. The gain and phase shift of the drive closed loop is controlled separately by an auto gain controller and an adjustable phase shifter. The chip is fabricated in a 0.35 μm CMOS process. The test of the chip is performed with a vibratory gyroscope, and the measurement shows that the noise floor is 0.003°/s√Hz, and the measured drift stability is 43°/h. Within -300 to 300°/s of rotation rate input range, the non-linearity is less than 0.1%.

关键词： capacitive interface circuit MEMS gyroscope low noise ASIC

Resistive switching characteristic of electrolyte-oxide-semiconductor structures

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2017年第8期38卷 32-37页

作者： Xiaoyu Chen Hao Wang Gongchen Sun Xiaoyu Ma Jianguang Gao Wengang Wu National Key Laboratory of Science and Technology on Micro/Nano Fabrication Institute of MicroelectronicsPeking University

The resistive switching characteristic of SiO2 thin film in electrolyte-oxide-semiconductor （EOS） struc- tures under certain bias voltage is reported. To analyze the mechanism of the resistive switching characteristic, a batch olEOS structures were fabricated under various conditions and their electrical properties were measured with a set of three-electrode systems. A theoretical model based on the formation and rupture of conductive filaments in the oxide layer is proposed to reveal the mechanism of the resistive switching characteristic, followed by an experimental investigation of Auger electron spectroscopy （AES） and secondary ion mass spectroscopy （SIMS） to verify the proposed theoretical model. It is found that different threshold voltage, reverse leakage current and slope value features of the switching I-V characteristic can be observed in different EOS structures with different elec- trolyte solutions as well as different SiO2 layers made by different fabrication processes or in different thicknesses. With a simple fabrication process and significant resistive switching characteristic, the EOS structures show great potential for chemical/biochemical applications.

关键词： electrolyte-oxide-semiconductor structure resistive switching characteristic conductive filament threshold voltage reverse leakage current

A monolithically integrated microcantilever biosensor based on partially depleted SOI CMOS technology

在线全文

学校读者我要写书评

暂无评论

微系统与纳米工程(英文) 2023年第3期9卷 273-283页

作者： Yi Liu Yuan Tian Cong Lin Jiahao Miao Xiaomei Yu School of Integrated Circuits Peking UniversityNational Key Laboratory of Science and Technology on Micro/Nano FabricationBeijing 100871China

This paper presents a monolithically integrated aptasensor composed of a piezoresistive microcantilever array and an on-chip signal processing circuit.Twelve microcantilevers,each of them embedded with a piezoresistor,form three sensors in a Wheatstone bridge configuration.The on-chip signal processing circuit consists of a multiplexer,a chopper instrumentation amplifier,a low-pass filter,a sigma-delta analog-to-digital converter,and a serial peripheral interface.Both the microcantilever array and the on-chip signal processing circuit were fabricated on the single-crystalline silicon device layer of a silicon-on-insulator(SOI)wafer with partially depleted(PD)CMOS technology followed by three micromachining processes.The integrated microcantilever sensor makes full use of the high gauge factor of single-crystalline silicon to achieve low parasitic,latch-up,and leakage current in the PD-SOI CMOS.A measured deflection sensitivity of 0.98×10^(−6) nm^(−1) and an output voltage fluctuation of less than 1μV were obtained for the integrated microcantilever.A maximum gain of 134.97 and an input offset current of only 0.623 nA were acquired for the on-chip signal processing circuit.By functionalizing the measurement microcantilevers with a biotin-avidin system method,human IgG,abrin,and staphylococcus enterotoxin B(SEB)were detected at a limit of detection(LOD)of 48 pg/mL.Moreover,multichannel detection of the three integrated microcantilever aptasensors was also verified by detecting SEB.All these experimental results indicate that the design and process of monolithically integrated microcantilevers can meet the requirements of high-sensitivity detection of biomolecules.

关键词： SOI amplifier cantilever

Insights of VG-dependent threshold voltage fluctuations from dual-point random telegraph noise characterization in nanoscale transistors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

science China(Information sciences) 2022年第8期65卷 297-298页

作者： Xuepeng ZHAN Jiezhi CHEN Zhigang JI School of Information science and Engineering Shandong University State key laboratory of High-end Server and Storage technology National Key Laboratory of Science and Technology on Micro/Nano Fabrication Shanghai Jiaotong University

Dear editor,Random telegraph noise(RTN) has attracted rising attention with the diminishing device size. In each device, the number of dopant atoms and defects reduces to quantifiable levels, resulting in higher time-zero and-dependent variability. RTN is observed as the sudden and random discrete drain current fluctuation under constant voltage,

关键词：

A CMOS compatible process for monolithic integration of high-aspect-ratio bulk silicon microstructures

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

science China(Information sciences) 2014年第8期57卷 180-186页

作者： QIAN Liang YANG ZhenChuan YAN GuiZhen National Key Laboratory of Science and Technology on Micro/Nano Fabrication Institute of MicroelectronicsPeking University

We report a CMOS compatible bulk micromachining method for the integration of high-aspectratio single crystal silicon MEMS(micro electromechanical systems)devices and signal conditioning circuit on a standard silicon wafer.The trench refilling and residual silicon removing techniques are used to acquire a proper electrical insulation between the different actuation and sensing elements situated on either fixed or movable parts of an MEMS device.To demonstrate the compatibility of the process,an integrated MEMS accelerometer was implemented.Test results show that the resistance between different elements of the device is larger than1012?.The electrical properties of the transistors that experienced MEMS fabrication agree well with those without MEMS process,indicting the CMOS compatibility of the process.

关键词： monolithic integration trench isolation CMOS compatibility high-aspect-ratio bulk micromachining