The micro-scale Ta2O5 thin film is a material with increasing attention in the semiconductor field due to its excellent performance. However, the properties of such material prepared by complex processes and expensive equipment are still difficult to guarantee. This paper proposed a novel process method for preparing the microscale Ta2O5 film, which can realize the preparation of Ta2O5 on a single chip. The foundation of this method is temperature control of the thermal bubble resistor. In the absence of external devices, the frequency and heating time can be flexibly controlled by the written digital signals. On this basis, we used COMSOL to build a physical model of the thermal bubble nozzle. The simulation results showed that the nozzle produced a temperature of about 500 750 degrees C, which proved the feasibility of this method. Finally, we designed and fabricated a thermal bubble printing chip integrated with 1104 nozzles, and realized the preparation of Ta2O5 films on it. The properties of Ta2O5 were analyzed using XPS, SEM, and 3D surface profilometer. The results demonstrated that the surface of the Ta2O5 film prepared by this method was compact and uniform. The thickness was approximately 400 600 nm, and no crack were present. The surface roughness was up to 0.432 mu m, indicating that the film had a high surface area. It is expected to be used in the design and development of miniaturized sensors in the future.

Single-cell printing technology has arisen as a potent instrument for investigating cell biology and disease pathophysiology. Nonetheless, current single-cell printing methodologies are hindered by restricted throughput, a limited field of view, and diminished efficiency. We present an innovative single-cell printing chip that utilizes thermal inkjet technology for single-cell printing, therefore addressing these constraints. We have accomplished high-throughput, wide-field, and efficient single-cell printing by merging a high-density thermal foam-based inkjet nozzle array on a chip with high-speed cameras and computer vision technologies for optical image capture and single-cell identification training. We have shown the efficacy and adaptability of the printing chip by printing various concentrations of Chinese hamster ovary cells and human embryonic kidney 293 cells. The printing of a single 96-well plate is accomplished in 2-3 min, facilitating one-time loading and uninterrupted multi-plate paving. Our thermal bubble single-cell printing chip serves as a viable platform for high-throughput single-cell analysis applications.

Electrochemical impedance spectroscopy (EIS) flow cytometry offers the advantages of speed, affordability, and porta-bility in cell analysis and cytometry applications. However, the integration challenges of microfluidic and EIS read-out circuits hin-der the downsizing of cytometry devices. To address this, we developed a thermal-bubble-driven impedance flow cytometric application-specific integrated circuit (ASIC). The thermal-bubble micropump avoids external piping and equipment, enabling high-throughput designs. With a total of 36 cell counting channels, each measuring 884 × 220 μm2, the chip significantly enhances the throughput of flow cytometers. Each cell counting channel incorporates a differential trans-impedance amplifier (TIA) to amplify weak biosensing signals. By eliminating the parasitic parameters created at the complementary metal-oxide-semiconductor transistor (CMOS)-micro-electromechanical systems (MEMS) interface, the counting accuracy can be increased. The on-chip TIA can adjust feedback resistance from 5 to 60 kΩ to accommodate solutions with different impedances. The chip effectively classifies particles of varying sizes, demonstrated by the average peak voltages of 0.0529 and 0.4510 mV for 7 and 14 μm polystyrene beads, respectively. Moreover, the counting accuracies of the chip for polystyrene beads and MSTO-211H cells are both greater than 97.6％. The chip exhibits potential for impedance flow cytometer at low cost, high-throughput, and miniaturization for the application of point-of-care diagnostics.

The isolation of single cells is essential for the development of single cell analysis methods, such as single-cell sequencing, monoclonal antibodies, and drug development. Traditional single-cell isolation techniques include flow cytometry (FACS), laser capture microdissection (LCM), micromanipulation, etc., but their operations are complex and have low throughput. Here, we present a microfluidic chip that can isolate individual cells from cell suspension and release them onto a well plate. It uses thermal bubble micropump technology to drive the fluid flow, and single-cell isolation is achieved by matching the flow resistance of the flow channel. Therefore, injection pumps and peristaltic pumps are not required for cell loading. Because of its small size, we can integrate hundreds of single-cell functional modules, which makes high-throughput single-cell isolation possible. For polystyrene beads, the capture rate of the single bead is close to 100%. Finally, the method has been applied to cells, and the capture rate of the single cell is also about 75%. This is a promising method for single-cell isolation.

The rational integration of many microfluidic chips and micropumps remains challenging. Due to the integration of the control system and sensors in active micropumps, they have unique advantages over passive micropumps when integrated into microfluidic chips. An active phase-change micropump based on complementary metal–oxide–semiconductor–microelectromechanical system (CMOS-MEMS) technology was fabricated and studied theoretically and experimentally. The micropump structure is simple and consists of a microchannel, a series of heater elements along the microchannel, an on-chip control system, and sensors. A simplified model was established to analyze the pumping effect of the traveling phase transition in the microchannel. The relationship between pumping conditions and flow rate was examined. Based on the experimental results, the maximum flow rate of the active phase-change micropump at room temperature is 22 µL/min, and long-term stable operation can be achieved by optimizing heating conditions.

Cell identification and enumeration are important methods within clinical and research laboratories for rapid diagnosis of relevant diseases. However, there are still many shortcomings in the current cell counting methods. In order to improve the performance of cell counting, a novel impedance-based cell counting chip based on thermal bubble drive was designed in this study. The chip is fabricated by whole-wafer processing and provides the driving force for cells through a combination of thermal bubble nozzles and microfluidic channels, integrating 100 individual detection units on a 38 mm2 size chip. Experimental and theoretical analyses have demonstrated that the chip can achieve high throughput detection of 45 000 beads/s under extreme conditions. A fourfold difference in detection voltage was obtained for both 14 and 7 µm diameter polystyrene beads. The linear fit coefficient of determination between the cell number measured by the chip and the cell number observed in reality was above 0.999 for both polystyrene beads and 211H cells, and the counting accuracy exceeded previous studies. It turns out that the chip achieves portable, low-cost, high-throughput, and high-accuracy cell counting, which is conducive to the development of impedance cell counting.

传统单细胞分离技术包含流式细胞术、激光捕获法和显微操作法等.然而,流式细胞术需要大量样本,且仪器体积庞大,价格昂贵;激光捕获法和显微操作法则耗时长,并且单细胞获取效率和通量较低.将热发泡喷墨技术应用于单细胞打印.利用热发泡喷嘴驱动细胞悬液,因此无需外接注射泵,并在芯片上集成大量喷嘴,实现高通量单细胞打印.首先通过OpenCV算法分割喷嘴图像,然后通过卷积神经网络(CNN)对带有单细胞的喷嘴图像进行训练和识别,最后控制喷嘴实现单细胞打印.实现了对浓度1× 106 cells/mL的CHO-K1+CDCHO和CHO-K1+DMEM/F12+FBS两种细胞悬液的16块96孔板单细胞打印,单个96孔板分选在5 min内完成.两种细胞悬液即时细胞活性损耗分别为9.1％和8.3％,单细胞打印率分别达到86.7％和87.3％,单细胞克隆率分别达到44.5％和36.9％.

Currently, many microchips must rely on an external force (such as syringe pump, electro-hydrodynamic pump, and peristaltic pump, etc.) to control the solution in the microchannels, which probably adds manual operating errors, affects the accuracy of fluid manipulation, and enlarges the noise of signal. In addition, the reasonable integration of micropump and microchip remain the stumbling block for the commercialization of microfluidic technique. To solve those two problems, we designed and fabricated a thermal bubble micropump based on MEMS (micro-electro-mechanical systems) technique. Many parameters (voltage, pulse time, cycle delay time, etc.) affecting the performance of this micropump were explored in this work. The experimental results showed the flow rate of solution with the assistance of a micropump reached more than 15 μL/min in the optimal condition. Finally, a method about measuring total aflatoxin in Chinese herbs was successfully developed based on the integrated platform contained competitive immunoassay and our micropump-based microfluidics. Additionally, the limit of detection in quantifying total aflatoxin (AF) was 0.0615 pg/mL in this platform. The data indicate this combined technique of biochemical assays and micropump based microchip have huge potential in automatically, rapidly, and sensitively measuring other low concentration of biochemical samples with small volume.

设计了一款集成于微电子机械系统(MEMS)器件专用集成电路(ASIC)的数字输出CMOS温度传感器.该温度传感器主要由温度敏感电路、一阶∑-△调制器以及配套的偏置电路和时钟产生电路组成.通过分析和建模仿真,确定信号的比例系数和其他设计参数,优化调制器的动态范围,提高了精度.利用斩波技术减少运算放大器低频噪声.通过对运算放大器和比较器电路的合理设计来降低功耗.该单片集成温度传感器电路采用0.18 μm CMOS工艺制造.测试结果表明,-45～85℃下电源电压为1.8V、采样时钟频率为200 kHz、设置带宽为98 Hz时过采样率为1 024,此温度传感器分辨率达到0.03℃,功耗为0.18 mW.

This paper considers points of secure and anti-collision of the Radio-frequency identification (RFID) technology. Source symbols are represented by a special coding, termed Minimum Energy (ME) coding, which exploits redundant bits for saving power when transmitted via RF links with On-Off Keying (OOK). This ME coding is applied to Direct Sequence Spread Spectrum (DSSS) RFID tag in order to enhance security as well as to reduce collision. This synchronized DSSS RFID system is designed and simulation is conducted to verify the advantage of DSSS RFID and present the power efficiency enhance 4 dB, quantities are taken at Bit Error Rate (BER) of 10e-4. When the channel uses the ME coding combined with a DSSS code and OOK without FM0 encoding as is disclosed in the EPC-C1G2/ISO 18000-6 Type C standard. Finally, the maximum number of users in this Direct-Sequence Code Division Multiple Access (DS-CDMA) RFID system is calculated under the condition of successfully acquired.

This paper describes an ultralow power wireless intraocular pressure (IOP) monitoring system that is dedicated to sensing and transferring intraocular pressure of glaucoma patients. Our system is comprised of a capacitive pressure sensor, an application-specific integrated circuit, which is designed on the SMIC 180 nm process, and a dipole antenna. The system is wirelessly powered and demonstrates a power consumption of 7.56 μW at 1.24 V during continuous monitoring, a significant reduction in active power dissipation compared to existing work. The input RF sensitivity is −13 dBm. A significant reduction in input RF sensitivity results from the reduction of mismatch time of the ASK modulation caused by FM0 encoding. The system exhibits an average error of ± 1.5 mmHg in measured pressure. Finally, a complete IOP system is demonstrated in the real biological environment, showing a successful reading of the pressure of an eye.

The implantable intraocular pressure detection microsystem is a system which can be implanted in eyes to detect intraocular pressure continuously and transmit the signal to outside.The system is summarized according to the research progress of the system in recent years.The principle and development of LC oscillation and SoC structure always used in the system are introduced,and the main technical indexes,fabrication process and existing problems are analyzed.Based on bioelectromagnetics,MEMS technology and IC technology,the development status,existing problems and breakthrough directions of the key technologies such as antenna,circuit system and pressure sensor are analyzed.Then the application level problems such as biological compatibility materials and implant position are summarized and prospected.At last,the deve-lopment direction of the system is prospected according to the existing problems of the system.

The problem of the collision when multiple tags access to a reader at the same must be solved in RFID system.This paper introduces the anti—collision algorithm in the EPC Gen2 protocol,and optimize the standard Q value adjustment algorithm and multi—tag reading mechanisms under the conditions that do not change the original order form and not to increase the command,through the analysis of a variety of programs to propose an optimized multi—label response mechanism.

A heavy metal sensor fabricated by microelectronic mechanical system (MEMS) technology was described in this study. The sensor is three-electronic system which consisted of Bi microelectronic array working electrode, Pt counter electrode and Ag/AgCl reference electrode. Bi is low-toxic heavy metal, so the using of Bi as reaction substances can make detection process more safely. Microarray electrode takes many advantages, such as high-throughput, miniaturization and anti-interference. The experiment result shows that the sensor has a good performance in simultaneously detecting Pb2+, Cd2+. The detection limits of these two metals are 0.067 mg/L (Pb) and 0.064 mg/L (Cd) respectively with good repeatability. The sensor has been applied to detect Pb2+ (0.1 mg/L) and Cd2+ (0.025 mg/L) in Orange juice with satisfactory results.

The front-end design of the impedance-based biosensor for rapid detection of bacterial has been completed based on the impedance microbiology.Proper experimental scheme is designed to research the impedance change during the Escherichia coli growth.The slope of Nyquist plots is chosen to characterize the bacterial quantity.The measurement results is analyzed,and experiments are designed to verify it.The changes are explained in the Nyquist slope during the bacterial growth.And the results are in agreement with the theoretical derivation.The analysis method reduces the requirements of microelectrodes and measuremental environment and shortens the time,which can be used for rapid detection of microorganisms.