DIAMOND AND RELATED MATERIALS
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2024
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IF 4.3
Biao Yan,Zhixin Zhao,Xiaojuan Wu,Haoran Li,Duo Liu
Diamond shows great potentials as an ultimate material candidate for application in microelectromechanical systems (MEMS). In this work, we report microcontact printing (μCP) transfer as a facile technique to fabricate diamond MEMS cantilever arrays. We started from the Deryaguin–Landau–Verwey–Overbeek (DLVO) principles and formulated a colloidal “ink” that contains nanodiamonds (NDs) seeds well dispersed in polymethyl methacrylate/acetone. The NDs seeds were then transfer printed onto a silicon (100) substrate by using a flexible polydimethylsiloxane (PDMS) stamp with predefined pattern. The densely packed NDs pattern (∼10 9 cm −2 ) enables facile and selected-area growth of diamond with microwave plasma chemical vapor deposition (MPCVD) technique. A diamond film with minimal graphite contaminants and low residual stresses was obtained after growth at 1118 K for 3 h. The diamond cantilevers were released from the substrate by wet chemical etching using KOH (40 % wt.) and isopropyl alcohol (10 % vol.). An examination of the vibrational kinetics indicates that the diamond film has a high Young's modulus (∼795 GPa) and the cantilevers exhibit consistently distributed resonant frequencies and high quality factors in ambient air. The method opens the door for large-scale, cost-effective production of uniform diamond MEMS devices for sensor and quantum applications.
研究领域:
材料科学
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微机电系统
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表面化学
✓ 已验证
产品关联
DOI
高影响因子
SENSORS
·
2023
·Vol. 23
·期 3
·1362
·
IF 3.9
Haozhi Zhang,Hao Jia,Weiwen Feng,Zao Ni,Pengcheng Xu,Xinxin Li
Ultra-responsive single-crystal silicon MEMS thermopiles for differential thermal analysis (DTA) are developed. Facilitated by a unique “microholes interetch and sealing (MIS)” technique, pairs of suspended thermopiles are batch fabricated in a differential form, with high-density (54 pairs) n-type/p-type single-crystal silicon thermocouples integrated within each thermopile (sample area ~0.045 mm2). The fabricated MEMS thermopile sensors exhibit outstanding power responsivity of 99.5 V/W and temperature responsivity of 27.8 mV/°C, which are more than 4 times higher than those reported for material thermal analysis. The high-responsivity MEMS DTA chips allow us to accurately measure the indium melting point at different heating rates of ~1–100 °C/s. We also perform DTA measurement of the dehydration process of CuSO4·5H2O and the crystals show three stages of losing water of crystallization before becoming anhydrous copper sulfate salt. Our high-performance, cost-effective MEMS sensing chips hold promise for rapid and accurate DTA characterization for a wide range of applications.Keywords:MEMS thermopile;differential thermal analysis;DTA;single-crystal silicon thermocouples;MIS process
研究领域:
材料科学
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微机电系统
·
热分析技术
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产品关联
DOI
PubMed
高影响因子
ACS Applied Nano Materials
·
2025
·
IF 5.5
Yong Yan,Xigui Lan,Yuzhou Li,Meihua Liang,Xiaodong Liu,Jiaxuan Yang,Rongrong Jia,Yuanyuan Ge,Zhili Li,Lei Huang
The development of highly sensitive and ultralow-power NO2 sensors is crucial for real-time NO2 monitoring. This study synthesizes tiny SnO2 nanoparticles with enriched oxygen vacancies for use in microelectromechanical system (MEMS) gas sensors, enabling ppb-level NO2 detection at reduced operating temperatures. PVP was used to adjust the particle size and surface oxygen vacancies in the hydrothermal method. The gas sensing performance shows that the 0.75 g PVP-SnO2 exhibited the highest response of 14.7 to 500 ppb NO2 at a low operating temperature of 102 °C, which is 3.2 times higher than that of the 0.00 g PVP-SnO2 sensor under the same conditions. Compared to similar studies, this sensor achieved a high response value and ultralow power consumption of 8.4 mW. The improvement in performance is mainly attributed to N doping and the abundance of oxygen vacancies. This research presents a promising strategy for the development of high-performance, low-energy, real-time NO2 gas sensors.
研究领域:
材料科学
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环境监测
·
传感器技术
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产品关联
DOI
高影响因子
Microsystems & Nanoengineering
·
2024
·Vol. 10
·期 1
·1-13
·
IF 7.3
Li Min,Qin Guangzhao,Jia Chen,Zhang Danyu,Li Zhikang,Han Xiangguang,Xu Shusheng,Zhao Libo,Luo Guoxi,Liu Cunlang,Yang Ping,Lin Qijing
With the rapid development of various fields, including aerospace, industrial measurement and control, and medical monitoring, the need to quantify flow velocity measurements is increasing. It is difficult for traditional flow velocity sensors to fulfill accuracy requirements for velocity measurements due to their small ranges, susceptibility to environmental impacts, and instability. Herein, to optimize sensor performance, a flexible microelectromechanical system (MEMS) thermal flow sensor is proposed that combines the working principles of thermal loss and thermal temperature difference and utilizes a flexible cavity substrate made of a low-thermal-conductivity polyimide/SiO 2 (PI/SiO 2 ) composite porous film to broaden the measurement range and improve the sensitivity. The measurement results show that the maximum measurable flow velocity can reach 30 m/s with a resolution of 5.4 mm/s. The average sensitivities of the sensor are 59.49 mV/(m s −1 ) in the medium-to-low wind velocity range of 0–2 m/s and 467.31 mV/(m s −1 ) in the wind velocity range of 2–30 m/s. The sensor proposed in this work can enable new applications of flexible flow sensors and wearable devices.
研究领域:
微机电系统
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传感器技术
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Surfaces and Interfaces
·
2025
·
IF 6.3
Danyang Wang,Menghan Xu,Kuangyi Li,Yong Yan,Xue Chen,Dongqi Yu,Rongrong Jia,Lei Huang
Ethanol sensors with low energy consumption and high performance have been applied in a wide range of areas. In this work, Pt-modified SnO 2 -TiO 2 composite nanomaterials prepared through ball milling and impregnation-reduction are fabricated for constructing microelectromechanical systems (MEMS) ethanol sensor. Tiny Pt nanoparticles are found uniformly dispersed on SnO₂-TiO₂. High quality gas-sensitive films are concentrated in the functional area of the MEMS chip. The loading of Pt significantly enhances the response to ethanol and reduced the optimal operating temperature. The 1.5% platinum-modified composite (A-ST) demonstrates a significant improvement in sensitivity to 50 ppm ethanol, with its response rising from 21.3 to 52.1, while the optimal operating temperature is reduced by 28°C, dropping from 288°C to 260°C. The limit of detection (LOD) is 240 ppb. This enhancement is primarily due to the n-n junction at the interface between SnO 2 and TiO 2 , along with the chemical and electronic sensitization effects generated by Pt on SnO 2 -TiO 2 .
研究领域:
材料科学
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传感器技术
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纳米科技
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
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2023
·
IF 4.8
Yongfeng Mu,Pengfei Jin,Li Zheng,Chao Wang,Yanjie Hou,Weiwei Liu,Liangyou Si,Zhihui Liu
Polymers have been widely used in the fabrication of humidity sensing materials, although, issues including sensitivity and hysteresis still exist, limiting its potential. Herein, we aim to enhance the humidity sensing performances of a polyimide (PI) capacitive-type relative-humidity sensor via a simple and efficient approach. Specifically, modified halloysite nanotubes (HNTs) were doped in the polyimide sensing layer to optimize the humidity sensing capabilities of the MEMS (Micro-electromechanical Systems)-based sensor. The configurational and morphological characteristic of the sensing membrane with different content of the nanofiller were characterized. The humidity sensing capabilities of the enhanced sensors were investigated under the relative humidity (RH) range of 10–90%. Owing to the rational structure design of the sensing layer, the modified sensor exhibited enhanced sensitivity, low humidity hysteresis and good linearity. The highest sensitivity of the device with the best overall performance reached 0.87 pF/%RH, which is 1.81 times that of the pure PI based humidity sensor. Meanwhile, the sensor maintained moderate humidity hysteresis (2.18%) as well as good linearity (R 2 = 0.9813) within the humidity boundary from 10 to 90% RH. The aforementioned advantages of the PI-HNTs-NH 2 based humidity sensor demonstrate its promising application in humidity measurement. As a low-cost and effective additive, HNTs own great application potential in the preparation of polymer sensing devices. This work provides valuable guidance for fabricating humidity sensors with outstanding sensing performances.
研究领域:
材料科学
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传感器技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Sensors
·
2025
·
IF 9.1
Junming Shao,Renjun Si,Hongze Jiang,Shaofeng chen,Jiabao Ding,Zheng Wang,Shunping Zhang
Aiming at the issue of poor selectivity in metal oxide gas sensors, a novel MEMS gas sensor structure was designed, comprising an adsorption unit and a sensing unit. Based on this design, a gas-sensing method utilizing on-chip programmable temperature analysis technology was developed. By quantifying the gas-sensitive response, we successfully extracted the peak signal of temperature-dependent resistance with high selectivity. The performance results show that ZSM-5, as the adsorbent material, exhibits desorption peak positions at different temperatures for four types of alcohol gases, and the peak height is correlated with the adsorption concentration. The essence of its high selectivity lies in the fact that materials have different desorption activation energies for different gases under the same conditions. This study proposes a new selective MEMS device testing method for identifying gas types and concentrations.
研究领域:
微纳传感技术
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气体传感
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材料科学
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分析化学
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半导体器件
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环境监测
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Small
·
2025
·
IF 12.1
Mianyi Xiang,Yamin Liu,Ziyang Yang,Jinlei Jiang,Weicheng Wang,Yao Hu,Daxiang Cui,Qichao Li
Electronic noses (e-noses) have become indispensable analytical platforms for gas detection. However, conventional e-nose systems face significant limitations in portable and wearable implementations due to their bulk and high-power consumption. Herein, a single-sensor-based multifunctional e-nose system is reported by integrating a micro-electromechanical system (MEMS) gas sensor with a flexible printed circuit board (FPCB). Specifically, the ZnO-ZnSnO 3 raspberry-like microspheres (ZZSRM) are utilized as the gas-sensitive materials, and the gas selectivity of the sensor is enhanced through a dual-temperature modulation strategy. Additionally, a gas classification model based on the MiniRocket algorithm has been developed, enabling efficient feature extraction and low-complexity classification of response signals, thereby satisfying the real-time processing demands of embedded devices. Moreover, a silent communication method is proposed, which maps breathing frequency to Morse code for information transmission in specific scenarios. Experimental results demonstrate that the wearable system achieves high-precision classification and concentration prediction for eight volatile organic compounds (VOCs), while simultaneously enabling robust recognition of exhaled signals and instantaneous conversion of Morse code into legible alphabetic characters. By combining the gas sensor with artificial intelligence (AI) technology, this work establishes a multifunctional flexible e-nose that merges portable gas detection and silent communication, offering a novel technological framework for environmental monitoring and human-machine interaction.
研究领域:
生物医学工程
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微机电系统
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气体检测
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人工智能
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可穿戴设备
✓ 已验证
DOI
PubMed
高影响因子
SENSORS
·
2025
·Vol. 25
·期 9
·2634
·
IF 3.5
Mengxue Xu,Yihong Zhong,Hongpeng Zhang,Yi Tao,Qingqing Shen,Shumin Zhang,Pingping Zhang,Xiaochun Hu,Xingqi Liu,Xuhui Sun,Zhenxing Cheng
HighlightsWhat are the main findings?The problem of dichloromethane “poisoned” MOS materials was well solved.Gas sensing mechanism of dichloromethane on the MOS material was elucidate.What is the implication of the main finding?The best performance of significant response and excellent recoverability by the MEMS sensor to dichloromethane is attributed to a synergetic effect from Mo and Ni co-doping into SnO2.Kinetically, the transportation of dichloromethane molecules onto the surface determines the response process. Thermodynamically, the output steady electronic signal of the MEMS sensor follows the equations newly derived by statistical mechanics.The challenging problem of chlorine “poisoning” SnO2for poorly recoverable detection of dichloromethane has been solved in this work. The materials synthesized by Ni or/and Mo doping SnO2were spread onto the micro-hotplates (<1 mm3) to fabricate the MEMS sensors with a low power consumption (<45 mW). The sensor based on Mo·Ni co-doped SnO2is evidenced to have the best sensing performance of significant response and recoverability to dichloromethane between 0.07 and 100 ppm at the optimized temperature of 310 °C, in comparison with other sensors in this work and the literature. It can be attributed to a synergetic effect of Mo·Ni co-doping into SnO2as being supported by characterization of geometrical and electronic structures. The sensing mechanism of dichloromethane on the material is investigated. In situ infrared spectroscopy (IR) peaks identify that the corresponding adsorbed species are too strong to desorb, although it has demonstrated a good recoverability of the material. A probable reason is the formation rates of the strongly adsorbed species are much slower than those of the weakly adsorbed species, which are difficult to form significant IR peaks but easy to desorb, thus enabling the material to recover. Theoretical analysis suggests that the response process is kinetically determined by molecular transport onto the surface due to the free convection from the concentration gradient during the redox reaction, and the output steady voltage thermodynamically follows the equation only formally identical to the Langmuir–Freundlich equation for physisorption but is newly derived from statistical mechanics.
研究领域:
材料科学
·
传感器技术
·
物理化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Small
·
2025
·
IF 12.1
Yanlin Zhang,Changming Zhang,Zheng Zhang,Huakang Zong,Pengwei Tan,Liyang Luo,Yuanyuan Luo,Guotao Duan
In the sensing field, the electronic structure of sensing materials has a great influence on the properties of the sensors. Here, by Ga doping pure rhombohedral In 2 O 3 (h-In 2 O 3 ), the double-phase In 2 O 3 (cubic/rhombohedral In 2 O 3 , c/h-In 2 O 3 ) porous nanospheres are obtained. And then Micro Electromechanical System (MEMS) gas sensors based on monolayer film are further fabricated by self-assembling the above nanospheres. The 5% Ga-doped In 2 O 3 sensors exhibit excellent HCHO sensing performance with a high-response (110.6@100 ppm), rapid response/recovery time (5.2/18.4 s) and low limit of detection (50 ppb) at an operating temperature of 180 °C. The 5% Ga-doped In 2 O 3 sensors also show high consistency (fluctuations of only 8.3%). Besides, a handheld device is developed to enable real-time monitoring and early warning of indoor HCHO at ppb-level. Based on experimental results and DFT theoretical calculation, the enhanced sensing mechanism is revealed, which is correlated with the optimization of electronic band structure by Ga doping and the appearance of double-phase heterostructures caused by Ga doping. Therefore, the relationship between electronic structure and gas sensing properties has also been established. This work significantly introduces a novel approach for the mass production of MEMS gas sensors, ensuring high sensitivity, repeatability and consistency.
研究领域:
材料科学
·
传感器技术
·
环境监测
✓ 已验证
DOI
PubMed
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 8
·1703
·
IF 4.2
Meihua Liang,Yong Yan,Jiaxuan Yang,Xiaodong Liu,Rongrong Jia,Yuanyuan Ge,Zhili Li,Lei Huang
Microelectromechanical systems (MEMS) gas sensors have numerous advantages such as compact size, low power consumption, ease of integration, etc., while encountering challenges in sensitivity and high resistance because of their low sintering temperature. This work utilizes the in situ growth of Zeolitic Imidazolate Framework-8 (ZIF-8) followed by its conversion to N-doped ZnO. The results obtained from scanning electron microscopy (SEM) and transmission electron microscopy (TEM) indicate that the in situ derivation of ZIF-8 facilitates the adhesion of ZnO particles, forming an island-like structure and significantly reducing the interfaces between these particles. Furthermore, powder X-ray diffraction (XRD) analysis, elemental mapping, and X-ray photoelectron spectroscopy (XPS) analysis confirm the conversion of ZIF-8 to ZnO, the successful incorporation of N atoms into the ZnO lattice, and the creation of more oxygen vacancies. The ZIF-8-derived N-doped ZnO/MEMS sensor (ZIF (3)-ZnO/MEMS) exhibits remarkable gas sensitivity for ethanol detection. At an operating temperature of 290 °C, it delivers a substantial response value of 80 towards 25 ppm ethanol, a 13-fold enhancement compared with pristine ZnO/MEMS sensors. The sensor also exhibits an ultra-low theoretical detection limit of 11.5 ppb to ethanol, showcasing its excellent selectivity. The enhanced performance is attributed to the incorporation of N-doped ZnO, which generates abundant oxygen vacancies on the sensor’s surface, leading to enhanced interaction with ethanol molecules. Additionally, a substantial two-order-of-magnitude decrease in the resistance of the gas-sensitive film is observed. Overall, this study provides valuable insights into the design and fabrication strategies applicable to high-performance MEMS gas sensors in a broader range of gas sensing.
研究领域:
材料科学
·
化学传感器
·
纳米技术
·
微机电系统（MEMS）
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LAB ON A CHIP
·
2023
·Vol. 23
·期 20
·4493-4503
·
IF 6.1
Wei Liu,Yongan Feng,Yapeng Yao,Zihang Liang,Fei Xiao,Zhongliang Ma
Integrating energetic materials with microelectromechanical systems (MEMS) to achieve miniaturized integrated smart energetic microchips has broad application prospects in miniaturized aerospace systems and civil explosive systems. In this work, MEMS compatible [Cu(BODN)·5H2O]n arrays and [Cu(BODN)·5H2O]n@nano-Al composite energetic films were successfully fabricated on copper substrates by the in situ reaction method and drop-coating method. Single crystal X-ray diffraction, powder X-ray diffraction, scanning electron microscopy, infrared spectroscopy, differential thermal analyses, and pulsed laser ignition were employed to characterize the prepared samples. The results show that [Cu(BODN)·5H2O]n arrays formed by the coordination reaction between the Cu(OH)2 template and the BODN ligand exhibit a porous supramolecular structure with excellent thermal and energy properties. Their morphology and composition on a copper substrate can be effectively regulated by adjusting the reaction time and solution concentration. In addition, adjustable energetic properties of [Cu(BODN)·5H2O]n@nano-Al composite films can be achieved after the encapsulation of nano-Al. Their heat release, flame height and ignition duration can reach as much as 1987.5 J g−1, 13.2 mm, and 5900 μs, respectively, indicating that [Cu(BODN)·5H2O]n@nano-Al can be used as an excellent pyrotechnic agent in MEMS ignition chips. Overall, this work provides a reference for the integration and application of energetic materials in MEMS systems.
研究领域:
材料科学
·
微机电系统
·
能量材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）