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Zhu B, Xu Z, Liu X, Wang Z, Zhang Y, Chen Q, Teh KS, Zheng J, Du X, Wu D. High-Linearity Flexible Pressure Sensor Based on the Gaussian-Curve-Shaped Microstructure for Human Physiological Signal Monitoring. ACS Sens 2023; 8:3127-3135. [PMID: 37471516 DOI: 10.1021/acssensors.3c00818] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/22/2023]
Abstract
Flexible pressure sensors with high-performance show broad application prospects in health monitoring, wearable electronic devices, intelligent robot sensing, and other fields. Although flexible pressure sensors have made significant progress in sensitivity and detection range, most of them still exhibit strong nonlinearity, which leads to significant troubles in signal acquisition and thus limits their popularity in practical applications. It remains a serious challenge for the flexible pressure sensor to achieve high linearity while maintaining high sensitivity. Herein, a doped sensing membrane with a uniformly distributed Gaussian-curve-shaped micropattern array was developed using the micro-electromechanical systems (MEMS) process, and a flexible sensor structure with the doped film as the core was designed and constructed. The prototype sensor has a high sensitivity of 1.77 kPa-1 and a linearity of 0.99 in the full detection range of 20 Pa to 30 kPa. In addition, its excellent performance also includes fast response/recovery times (∼25/50 ms) and long-term endurance (>10,000 cycles at 15 kPa). The prototype sensor has been successfully demonstrated in human pulse monitoring, speech recognition, and gesture recognition. The 2 × 6 sensor array can detect the spatial pressure distribution. Thus, such a microstructure shape design will open a new way to fabricate a high-linearity pressure sensor for potential applications in health monitoring, human-machine interaction, etc.
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Affiliation(s)
- Bin Zhu
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, China
| | - Zhenjin Xu
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, China
| | - Xin Liu
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, China
| | - Zhongbao Wang
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, China
| | - Yang Zhang
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, China
| | - Qinnan Chen
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, China
| | - Kwok Siong Teh
- School of Engineering, San Francisco State University, San Francisco, California 94132, United States
| | - Jianyi Zheng
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, China
| | - Xiaohui Du
- Sensor and network control center, Instrumentation Technology and Economy Institute, Beijing 100055, China
| | - Dezhi Wu
- Pen-Tung Sah Institute of Micro-Nano Science and Technology, Xiamen University, Xiamen 361005, China
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Yuan J, Li Z, Ma Q, Li J, Li Z, Zhao Y, Qin S, Shi X, Zhao L, Yang P, Luo G, Wang X, Teh KS, Jiang Z. Noninvasive fluid bubble detection based on capacitive micromachined ultrasonic transducers. Microsyst Nanoeng 2023; 9:20. [PMID: 36844939 PMCID: PMC9946994 DOI: 10.1038/s41378-023-00491-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Revised: 12/06/2022] [Accepted: 01/12/2023] [Indexed: 06/18/2023]
Abstract
Ultrasonic fluid bubble detection is important in industrial controls, aerospace systems and clinical medicine because it can prevent fatal mechanical failures and threats to life. However, current ultrasonic technologies for bubble detection are based on conventional bulk PZT-based transducers, which suffer from large size, high power consumption and poor integration with ICs and thus are unable to implement real-time and long-term monitoring in tight physical spaces, such as in extracorporeal membrane oxygenation (ECMO) systems and dialysis machines or hydraulic systems in aircraft. This work highlights the prospect of capacitive micromachined ultrasonic transducers (CMUTs) in the aforementioned application situations based on the mechanism of received voltage variation caused by bubble-induced acoustic energy attenuation. The corresponding theories are established and well validated using finite element simulations. The fluid bubbles inside a pipe with a diameter as small as 8 mm are successfully measured using our fabricated CMUT chips with a resonant frequency of 1.1 MHz. The received voltage variation increases significantly with increasing bubble radii in the range of 0.5-2.5 mm. Further studies show that other factors, such as bubble positions, flow velocities, fluid medium types, pipe thicknesses and diameters, have negligible effects on fluid bubble measurement, demonstrating the feasibility and robustness of the CMUT-based ultrasonic bubble detection technique.
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Affiliation(s)
- Jiawei Yuan
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi’an Jiaotong University (Yantai) Research Institute for Intelligent Sensing Technology and Systems, Xi’an Jiaotong University, 710049 Xi’an, China
- School of Mechanical Engineering, Xi’an Jiaotong University, 710049 Xi’an, China
| | - Zhikang Li
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi’an Jiaotong University (Yantai) Research Institute for Intelligent Sensing Technology and Systems, Xi’an Jiaotong University, 710049 Xi’an, China
- School of Mechanical Engineering, Xi’an Jiaotong University, 710049 Xi’an, China
- Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing, 265503 Yantai, China
| | - Qi Ma
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi’an Jiaotong University (Yantai) Research Institute for Intelligent Sensing Technology and Systems, Xi’an Jiaotong University, 710049 Xi’an, China
- School of Mechanical Engineering, Xi’an Jiaotong University, 710049 Xi’an, China
| | - Jie Li
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi’an Jiaotong University (Yantai) Research Institute for Intelligent Sensing Technology and Systems, Xi’an Jiaotong University, 710049 Xi’an, China
- School of Mechanical Engineering, Xi’an Jiaotong University, 710049 Xi’an, China
- School of Mechanical and Electrical Engineering, Shaanxi University of Science and Technology, Xi’an, 710049 Xi’an, China
| | - Zixuan Li
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi’an Jiaotong University (Yantai) Research Institute for Intelligent Sensing Technology and Systems, Xi’an Jiaotong University, 710049 Xi’an, China
- School of Mechanical Engineering, Xi’an Jiaotong University, 710049 Xi’an, China
| | - Yihe Zhao
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi’an Jiaotong University (Yantai) Research Institute for Intelligent Sensing Technology and Systems, Xi’an Jiaotong University, 710049 Xi’an, China
- School of Mechanical Engineering, Xi’an Jiaotong University, 710049 Xi’an, China
| | - Shaohui Qin
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi’an Jiaotong University (Yantai) Research Institute for Intelligent Sensing Technology and Systems, Xi’an Jiaotong University, 710049 Xi’an, China
- School of Mechanical Engineering, Xi’an Jiaotong University, 710049 Xi’an, China
| | - Xuan Shi
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi’an Jiaotong University (Yantai) Research Institute for Intelligent Sensing Technology and Systems, Xi’an Jiaotong University, 710049 Xi’an, China
- School of Mechanical Engineering, Xi’an Jiaotong University, 710049 Xi’an, China
| | - Libo Zhao
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi’an Jiaotong University (Yantai) Research Institute for Intelligent Sensing Technology and Systems, Xi’an Jiaotong University, 710049 Xi’an, China
- School of Mechanical Engineering, Xi’an Jiaotong University, 710049 Xi’an, China
- Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing, 265503 Yantai, China
| | - Ping Yang
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi’an Jiaotong University (Yantai) Research Institute for Intelligent Sensing Technology and Systems, Xi’an Jiaotong University, 710049 Xi’an, China
- School of Mechanical Engineering, Xi’an Jiaotong University, 710049 Xi’an, China
- Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing, 265503 Yantai, China
| | - Guoxi Luo
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi’an Jiaotong University (Yantai) Research Institute for Intelligent Sensing Technology and Systems, Xi’an Jiaotong University, 710049 Xi’an, China
- School of Mechanical Engineering, Xi’an Jiaotong University, 710049 Xi’an, China
- Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing, 265503 Yantai, China
| | - Xiaozhang Wang
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi’an Jiaotong University (Yantai) Research Institute for Intelligent Sensing Technology and Systems, Xi’an Jiaotong University, 710049 Xi’an, China
- School of Mechanical Engineering, Xi’an Jiaotong University, 710049 Xi’an, China
| | - Kwok Siong Teh
- School of Engineering, San Francisco State University, San Francisco, CA 94132 USA
| | - Zhuangde Jiang
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi’an Jiaotong University (Yantai) Research Institute for Intelligent Sensing Technology and Systems, Xi’an Jiaotong University, 710049 Xi’an, China
- School of Mechanical Engineering, Xi’an Jiaotong University, 710049 Xi’an, China
- Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing, 265503 Yantai, China
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3
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Luo G, Zhang Q, Li M, Chen K, Zhou W, Luo Y, Li Z, Wang L, Zhao L, Teh KS, Jiang Z. A flexible electrostatic nanogenerator and self-powered capacitive sensor based on electrospun polystyrene mats and graphene oxide films. Nanotechnology 2021; 32. [PMID: 34192681 DOI: 10.1088/1361-6528/ac1019] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/24/2021] [Accepted: 06/30/2021] [Indexed: 05/11/2023]
Abstract
Electrostatic nanogenerators or capacitive sensors that leverage electrostatic induction for power generation or sensing, has attracted significant interests due to their simple structure, ease of fabrication, and high device stability. However, in order for such devices to work, an additional power source or a post-charging process is necessary to activate the electrostatic effect. In this work, an electrostatic nanogenerator is fabricated using electrospun polystyrene (PS) mats and dip-coated graphene oxide (GO) films as the self-charged components. The electret performances of the PS mats and GO films are characterized via the electrostatic force microscopy phase shift and surface potential measurements. With a multilayer device structure that consists of top electrodes/GO films/spacer/electrospun PS mats/bottom electrodes, the resultant device acts as an electrostatic generator that operates in the noncontact mode. The nanogenerator can output a peak voltage of ca. 6.41 V and a peak current of ca. 6.57 nA at a rate of 1 Hz of mechanical compression, and with no attenuation of electrical outputs even after 50 000 cycles over a 13 h period. Furthermore, this as-prepared device is also capable of serving as a self-powered capacitive sensor for detection of tiny mechanical impacts and measurement of human finger bending. This results of this work provides a new avenue to easily fabricate electrostatic nanogenerators with high durability and self-powered capacitive sensors for the detection of small impacts.
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Affiliation(s)
- Guoxi Luo
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
- Xi'an Jiaotong University, Suzhou Institute, Suzhou, Jiangsu 215123, People's Republic of China
| | - Qiankun Zhang
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
| | - Min Li
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
| | - Ke Chen
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
| | - Wenke Zhou
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
| | - Yunyun Luo
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
| | - Zhikang Li
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
| | - Lu Wang
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
| | - Libo Zhao
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
- Xi'an Jiaotong University, Suzhou Institute, Suzhou, Jiangsu 215123, People's Republic of China
| | - Kwok Siong Teh
- School of Engineering, San Francisco State University, San Francisco, CA 94132, United States of America
| | - Zhuangde Jiang
- State Key Laboratory for Manufacturing Systems Engineering, International Joint Laboratory for Micro/Nano Manufacturing and Measurement Technologies, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
- School of Mechanical Engineering, Xi'an Jiaotong University, Xi'an, Shannxi 710049, People's Republic of China
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Mei X, Lu L, Xie Y, Yu YX, Tang Y, Teh KS. Preparation of Flexible Carbon Fiber Fabrics with Adjustable Surface Wettability for High-Efficiency Electromagnetic Interference Shielding. ACS Appl Mater Interfaces 2020; 12:49030-49041. [PMID: 33073568 DOI: 10.1021/acsami.0c08868] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In the 5G era, for portable electronics to operate at high performance and low power levels, the incorporation of superior electromagnetic interference (EMI) shielding materials within the packages is of critical importance. A desirable wearable EMI shielding material is one that is lightweight, structurally flexible, air-permeable, and able to self-clean. To this end, a bioinspired electroless silver plating strategy and a one-step electrodeposition method are utilized to prepare an EMI shielding fabric (CEF-NF/PDA/Ag/50-30) that possesses these desirable properties. Porous CEF-NF mats with a spatially distributed silver coating create efficient pathways for electron movement and enable a remarkable conductivity of 370 S mm-1. When tested within a frequency range of 8.2-12.4 GHz, this highly conductive fabric not only achieves an EMI shielding effectiveness (EMI SE of 101.27 dB at 5028 dB cm2 g-1) comparable to a very thin and light metal but also retains the unique properties of fabrics-being light, structurally flexible, and breathable. In addition, it exhibits a high contact angle (CA) of 156.4° with reversible surface wettability. After having been subjected to 1000 cycles of bending, the performance of the fabric only decreases minimally. This strategy potentially provides a novel way to design and manufacture an easily integrated EMI shielding fabric for flexible wearable devices.
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Affiliation(s)
- Xiaokang Mei
- School of Mechanical & Automotive Engineering, South China University of Technology, 381#Wushan Road, Guangzhou 510641, China
| | - Longsheng Lu
- School of Mechanical & Automotive Engineering, South China University of Technology, 381#Wushan Road, Guangzhou 510641, China
| | - Yingxi Xie
- School of Mechanical & Automotive Engineering, South China University of Technology, 381#Wushan Road, Guangzhou 510641, China
| | - Yu-Xiang Yu
- School of Chemistry and Chemical Engineering, South China University of Technology, 381#Wushan Road, Guangzhou 510641, China
| | - Yong Tang
- School of Mechanical & Automotive Engineering, South China University of Technology, 381#Wushan Road, Guangzhou 510641, China
| | - Kwok Siong Teh
- School of Engineering, San Francisco State University, San Francisco, California 94132, United States
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Mei X, Lu L, Xie Y, Wang W, Tang Y, Teh KS. An ultra-thin carbon-fabric/graphene/poly(vinylidene fluoride) film for enhanced electromagnetic interference shielding. Nanoscale 2019; 11:13587-13599. [PMID: 31290898 DOI: 10.1039/c9nr03603b] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Highly conductive carbon-based fibrous composites have become one of the most sought-after components in the field of electromagnetic interference (EMI) shielding due to their excellent comprehensive performance. In this work, a flexible nonwoven fabric consisting of carbon fibers (CFs) and polypropylene/polyethylene (PP/PE) core/sheath bicomponent fibers (ESFs), known as CEF-NF, is introduced into the graphene (GE)/poly(vinylidene fluoride) (PVDF) nanocomposite obtained by a solution casting method to fabricate a CEF-NF/GE/PVDF film. Disparate microstructures can be clearly observed in CEF-NF/GE/PVDF films with different graphene contents. Thanks to an internal porous network structure formed when the graphene content is high, this film exhibits better electrical conductivity. In the frequency range of 30-1500 MHz, this film can achieve a significantly high EMI shielding effectiveness (EMI-SE) value of about 48.5 dB at tiny thickness and density (1731.40 dB cm2 g-1), which are far better than many competitive materials. Moreover, this film exhibits adequate tensile strength and excellent flexibility, as the film's structural form can be retained even after multiple folding processes. In addition, by combining two-dimensional (2D) graphene and one-dimensional (1D) CF, the CEF-NF/GE/PVDF film achieves a remarkable in-plane thermal conductivity of 25.702 W m-1 K-1, making it an exceptional heat conductor. In summary, our results demonstrate that CEF-NF/GE/PVDF film is an excellent EMI shielding material that is light weight, highly flexible, and mechanically robust with outstanding thermal conductivity, which positions it superbly for applications in next-generation commercial portable electronics.
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Affiliation(s)
- Xiaokang Mei
- School of Mechanical & Automotive Engineering, South China University of Technology, 381#Wushan Road, Guangzhou, 510641, China.
| | - Longsheng Lu
- School of Mechanical & Automotive Engineering, South China University of Technology, 381#Wushan Road, Guangzhou, 510641, China.
| | - Yingxi Xie
- School of Mechanical & Automotive Engineering, South China University of Technology, 381#Wushan Road, Guangzhou, 510641, China.
| | - Wentao Wang
- School of Mechanical & Automotive Engineering, South China University of Technology, 381#Wushan Road, Guangzhou, 510641, China.
| | - Yong Tang
- School of Mechanical & Automotive Engineering, South China University of Technology, 381#Wushan Road, Guangzhou, 510641, China.
| | - Kwok Siong Teh
- School of Engineering, San Francisco State University, San Francisco, CA 94132, USA
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Dong L, Zheng P, Yang Y, Zhang M, Xue Z, Wang Z, Liu G, Li P, Teh KS, Su Y, Cai B, Wang G, Di Z. NO 2 gas sensor based on graphene decorated with Ge quantum dots. Nanotechnology 2019; 30:074004. [PMID: 30523993 DOI: 10.1088/1361-6528/aaf3d7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We report a NO2 gas sensor based on germanium quantum dots (GeQDs)/graphene hybrids. Graphene was directly grown on germanium through chemical vapor deposition and the GeQDs were synthesized via molecular beam epitaxy. The samples were characterized by atomic force microscope, Raman spectra, scanning electron microscope, x-ray photoelectron spectroscope and transmission electron microscope with energy dispersive x-ray. By introducing GeQDs on graphene, the gas sensor sensitivity to NO2 was improved substantially. With the optimization of the growth time of GeQDs (600 s), the response sensitivity to 10 ppm NO2 can be as high as 3.88, which is 20 times higher than that of the graphene sensor without GeQDs decoration. In addition, the 600 s GeQDs/graphene hybrid sensor exhibits fast response and recovery rates as well as excellent stability. Our work may provide a new route to produce low-power consumption, portable, and room temperature gas sensor which is amenable to mass production.
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Affiliation(s)
- Linxi Dong
- The Key Laboratory of RF Circuits and System of Ministry of Education, College of Electronic and Information, Hangzhou Dianzi University, Hangzhou 310018, People's Republic of China
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Li X, Cai W, Teh KS, Qi M, Zang X, Ding X, Cui Y, Xie Y, Wu Y, Ma H, Zhou Z, Huang QA, Ye J, Lin L. High-Voltage Flexible Microsupercapacitors Based on Laser-Induced Graphene. ACS Appl Mater Interfaces 2018; 10:26357-26364. [PMID: 30004667 DOI: 10.1021/acsami.8b10301] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
High-voltage energy-storage devices are quite commonly needed for robots and dielectric elastomers. This paper presents a flexible high-voltage microsupercapacitor (MSC) with a planar in-series architecture for the first time based on laser-induced graphene. The high-voltage devices are capable of supplying output voltages ranging from a few to thousands of volts. The measured capacitances for the 1, 3, and 6 V MSCs were 60.5, 20.7, and 10.0 μF, respectively, under an applied current of 1.0 μA. After the 5000-cycle charge-discharge test, the 6 V MSC retained about 97.8% of the initial capacitance. It also was recorded that the all-solid-state 209 V MSC could achieve a high capacitance of 0.43 μF at a low applied current of 0.2 μA and a capacitance of 0.18 μF even at a high applied current of 5.0 μA. We further demonstrate the robust function of our flexible high-voltage MSCs by using them to power a piezoresistive microsensor (6 V) and a walking robot (>2000 V). Considering the simple, direct, and cost-effective fabrication method of our laser-fabricated flexible high-voltage MSCs, this work paves the way and lays the foundation for high-voltage energy-storage devices.
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Affiliation(s)
- Xiaoqian Li
- Department of Mechanical Engineering , University of California , Berkeley , California 94709 , United States
- Key Laboratory of MEMS of the Ministry of Education , Southeast University , Nanjing 210096 , China
| | - Weihua Cai
- Department of Mechanical Engineering , University of California , Berkeley , California 94709 , United States
- School of Chemistry and Chemical Engineering , South China University of Technology , Guangzhou 510641 , China
| | - Kwok Siong Teh
- School of Engineering , San Francisco State University , San Francisco , California 94132 , United States
| | - Mingjing Qi
- Department of Mechanical Engineering , University of California , Berkeley , California 94709 , United States
| | - Xining Zang
- Department of Mechanical Engineering , University of California , Berkeley , California 94709 , United States
| | - Xinrui Ding
- Department of Mechanical Engineering , University of California , Berkeley , California 94709 , United States
| | - Yong Cui
- Department of Mechanical Engineering , University of California , Berkeley , California 94709 , United States
| | - Yingxi Xie
- Department of Mechanical Engineering , University of California , Berkeley , California 94709 , United States
| | - Yichuan Wu
- Department of Mechanical Engineering , University of California , Berkeley , California 94709 , United States
| | - Hongyu Ma
- Department of Mechanical Engineering , University of California , Berkeley , California 94709 , United States
| | - Zaifa Zhou
- Key Laboratory of MEMS of the Ministry of Education , Southeast University , Nanjing 210096 , China
| | - Qing-An Huang
- Key Laboratory of MEMS of the Ministry of Education , Southeast University , Nanjing 210096 , China
| | - Jianshan Ye
- School of Chemistry and Chemical Engineering , South China University of Technology , Guangzhou 510641 , China
| | - Liwei Lin
- Department of Mechanical Engineering , University of California , Berkeley , California 94709 , United States
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Fang X, Dong L, Zhao WS, Yan H, Teh KS, Wang G. Vibration-Induced Errors in MEMS Tuning Fork Gyroscopes with Imbalance. Sensors (Basel) 2018; 18:s18061755. [PMID: 29844301 PMCID: PMC6022183 DOI: 10.3390/s18061755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Revised: 05/24/2018] [Accepted: 05/24/2018] [Indexed: 06/08/2023]
Abstract
This paper discusses the vibration-induced error in non-ideal MEMS tuning fork gyroscopes (TFGs). Ideal TFGs which are thought to be immune to vibrations do not exist, and imbalance between two gyros of TFGs is an inevitable phenomenon. Three types of fabrication imperfections (i.e., stiffness imbalance, mass imbalance, and damping imbalance) are studied, considering different imbalance radios. We focus on the coupling types of two gyros of TFGs in both drive and sense directions, and the vibration sensitivities of four TFG designs with imbalance are simulated and compared. It is found that non-ideal TFGs with two gyros coupled both in drive and sense directions (type CC TFGs) are the most insensitive to vibrations with frequencies close to the TFG operating frequencies. However, sense-axis vibrations with in-phase resonant frequencies of a coupled gyros system result in severe error outputs to TFGs with two gyros coupled in the sense direction, which is mainly attributed to the sense capacitance nonlinearity. With increasing stiffness coupled ratio of the coupled gyros system, the sensitivity to vibrations with operating frequencies is cut down, yet sensitivity to vibrations with in-phase frequencies is amplified.
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Affiliation(s)
- Xiang Fang
- The Key Laboratory of RF Circuits and System of Ministry of Education, College of Electronic and Information, Hangzhou Dianzi University, Hangzhou 310018, China.
| | - Linxi Dong
- The Key Laboratory of RF Circuits and System of Ministry of Education, College of Electronic and Information, Hangzhou Dianzi University, Hangzhou 310018, China.
- State Key Laboratory of Functional Materials for Informatics, Chinese Academy of Sciences, Shanghai 200050, China.
| | - Wen-Sheng Zhao
- The Key Laboratory of RF Circuits and System of Ministry of Education, College of Electronic and Information, Hangzhou Dianzi University, Hangzhou 310018, China.
| | - Haixia Yan
- Department of Mechanics, School of Information Engineering, Hangzhou Dianzi University, Hangzhou 310018, China.
- State Key Laboratory for Manufacturing Systems Engineering, Xi'an Jiaotong University, Xi'an 710049, China.
| | - Kwok Siong Teh
- Department of Mechanics, School of Engineering, San Francisco State University, San Francisco, CA 94132, USA.
| | - Gaofeng Wang
- The Key Laboratory of RF Circuits and System of Ministry of Education, College of Electronic and Information, Hangzhou Dianzi University, Hangzhou 310018, China.
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Zang X, Shen C, Kao E, Warren R, Zhang R, Teh KS, Zhong J, Wei M, Li B, Chu Y, Sanghadasa M, Schwartzberg A, Lin L. Titanium Disulfide Coated Carbon Nanotube Hybrid Electrodes Enable High Energy Density Symmetric Pseudocapacitors. Adv Mater 2018; 30:1704754. [PMID: 29227556 DOI: 10.1002/adma.201704754] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 10/20/2017] [Indexed: 05/26/2023]
Abstract
While electrochemical supercapacitors often show high power density and long operation lifetimes, they are plagued by limited energy density. Pseudocapacitive materials, in contrast, operate by fast surface redox reactions and are shown to enhance energy storage of supercapacitors. Furthermore, several reported systems exhibit high capacitance but restricted electrochemical voltage windows, usually no more than 1 V in aqueous electrolytes. Here, it is demonstrated that vertically aligned carbon nanotubes (VACNTs) with uniformly coated, pseudocapacitive titanium disulfide (TiS2 ) composite electrodes can extend the stable working range to over 3 V to achieve a high capacitance of 195 F g-1 in an Li-rich electrolyte. A symmetric cell demonstrates an energy density of 60.9 Wh kg-1 -the highest among symmetric pseudocapacitors using metal oxides, conducting polymers, 2D transition metal carbides (MXene), and other transition metal dichalcogenides. Nanostructures prepared by an atomic layer deposition/sulfurization process facilitate ion transportation and surface reactions to result in a high power density of 1250 W kg-1 with stable operation over 10 000 cycles. A flexible solid-state supercapacitor prepared by transferring the TiS2 -VACNT composite film onto Kapton tape is demonstrated to power a 2.2 V light emitting diode (LED) for 1 min.
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Affiliation(s)
- Xining Zang
- Berkeley Sensor and Actuator Center, Berkeley, CA, 94704, USA
- Mechanical Engineering, University of California Berkley, Berkeley, CA, 94704, USA
| | - Caiwei Shen
- Berkeley Sensor and Actuator Center, Berkeley, CA, 94704, USA
- Mechanical Engineering, University of California Berkley, Berkeley, CA, 94704, USA
| | - Emmeline Kao
- Berkeley Sensor and Actuator Center, Berkeley, CA, 94704, USA
- Mechanical Engineering, University of California Berkley, Berkeley, CA, 94704, USA
| | - Roseanne Warren
- Mechanical Engineering, University of Utah, Salt Lake City, UT, 84112, USA
| | - Ruopeng Zhang
- National Center for Electron Microscopy, Lawrence Berkeley National Lab, Berkeley, CA, 94720, USA
| | - Kwok Siong Teh
- School of Engineering, San Francisco State University, San Francisco, CA, 94132, USA
| | - Junwen Zhong
- Berkeley Sensor and Actuator Center, Berkeley, CA, 94704, USA
- Mechanical Engineering, University of California Berkley, Berkeley, CA, 94704, USA
| | - Minsong Wei
- Berkeley Sensor and Actuator Center, Berkeley, CA, 94704, USA
- Mechanical Engineering, University of California Berkley, Berkeley, CA, 94704, USA
| | - Buxuan Li
- Mechanical Engineering, University of California Berkley, Berkeley, CA, 94704, USA
| | - Yao Chu
- Mechanical Engineering, University of California Berkley, Berkeley, CA, 94704, USA
| | | | - Adam Schwartzberg
- Molecular Foundry, Lawrence Berkeley National Lab, Berkeley, CA, 94720, USA
| | - Liwei Lin
- Berkeley Sensor and Actuator Center, Berkeley, CA, 94704, USA
- Mechanical Engineering, University of California Berkley, Berkeley, CA, 94704, USA
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10
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Wu D, Deng L, Sun Y, Teh KS, Shi C, Tan Q, Zhao J, Sun D, Lin L. A high-safety PVDF/Al2O3 composite separator for Li-ion batteries via tip-induced electrospinning and dip-coating. RSC Adv 2017. [DOI: 10.1039/c7ra02681a] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Composite membranes have been fabricated made of ultrafine PVDF fibers via a tip-induced electrospinning (TIE) process and Al2O3 nanoparticles via a dip-coating process.
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Affiliation(s)
- Dezhi Wu
- Dept. of Mechanical & Electrical Engineering
- Xiamen University
- Xiamen 361005
- China
| | - Lei Deng
- School of Aerospace Engineering
- Xiamen University
- Xiamen 361005
- China
| | - Yu Sun
- School of Aerospace Engineering
- Xiamen University
- Xiamen 361005
- China
| | - Kwok Siong Teh
- School of Engineering
- San Francisco State University
- San Francisco 94132
- USA
| | - Chuan Shi
- Industrial Research Institute of Nonwovens & Technical Textiles
- Qingdao University
- Qingdao 266071
- China
| | - Qiulin Tan
- Science and Technology on Electronic Test and Measurement Laboratory
- North University of China
- Taiyuan 030051
- China
| | - Jinbao Zhao
- College of Chemistry and Chemical Engineering
- Xiamen University
- Xiamen 361005
- China
| | - Daoheng Sun
- Dept. of Mechanical & Electrical Engineering
- Xiamen University
- Xiamen 361005
- China
| | - Liwei Lin
- Dept. of Mechanical & Electrical Engineering
- Xiamen University
- Xiamen 361005
- China
- Department of Mechanical Engineering
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11
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Luo G, Teh KS, Liu Y, Zang X, Wen Z, Lin L. Direct-Write, Self-Aligned Electrospinning on Paper for Controllable Fabrication of Three-Dimensional Structures. ACS Appl Mater Interfaces 2015; 7:27765-70. [PMID: 26592741 DOI: 10.1021/acsami.5b08909] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Electrospinning, a process that converts a solution or melt droplet into an ejected jet under a high electric field, is a well-established technique to produce one-dimensional (1D) fibers or two-dimensional (2D) randomly arranged fibrous meshes. Nevertheless, the direct electrospinning of fibers into controllable three-dimensional (3D) architectures is still a nascent technology. Here, we apply near-field electrospinning (NFES) to directly write arbitrarily shaped 3D structures through consistent and spatially controlled fiber-by-fiber stacking of polyvinylidene fluoride (PVDF) fibers. An element central to the success of this 3D electrospinning is the use of a printing paper placed on the grounded conductive plate and acting as a fiber collector. Once deposited on the paper, residual solvents from near-field electrospun fibers can infiltrate the paper substrate, enhancing the charge transfer between the deposited fibers and the ground plate via the fibrous network within the paper. Such charge transfer grounds the deposited fibers and turns them into locally fabricated electrical poles, which attract subsequent in-flight fibers to deposit in a self-aligned manner on top of each other. This process enables the design and controlled fabrication of electrospun 3D structures such as grids, walls, hollow cylinders, and other 3D logos. As such, this technique has the potential to advance the existing electrospinning technologies in constructing 3D structures for biomedical, microelectronics, and MEMS/NMES applications.
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Affiliation(s)
- Guoxi Luo
- College of Optoelectronic Engineering, Chongqing University , Chongqing 400044, China
- Department of Mechanical Engineering, University of California , Berkeley, California 94720, United States
| | - Kwok Siong Teh
- Department of Mechanical Engineering, University of California , Berkeley, California 94720, United States
- School of Engineering, San Francisco State University , San Francisco, California 94132, United States
| | - Yumeng Liu
- Department of Mechanical Engineering, University of California , Berkeley, California 94720, United States
| | - Xining Zang
- Department of Mechanical Engineering, University of California , Berkeley, California 94720, United States
| | - Zhiyu Wen
- College of Optoelectronic Engineering, Chongqing University , Chongqing 400044, China
| | - Liwei Lin
- Department of Mechanical Engineering, University of California , Berkeley, California 94720, United States
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Pedersen JD, Esposito HJ, Teh KS. Direct synthesis and characterization of optically transparent conformal zinc oxide nanocrystalline thin films by rapid thermal plasma CVD. Nanoscale Res Lett 2011; 6:568. [PMID: 22040295 PMCID: PMC3227690 DOI: 10.1186/1556-276x-6-568] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 10/31/2011] [Indexed: 05/31/2023]
Abstract
We report a rapid, self-catalyzed, solid precursor-based thermal plasma chemical vapor deposition process for depositing a conformal, nonporous, and optically transparent nanocrystalline ZnO thin film at 130 Torr (0.17 atm). Pure solid zinc is inductively heated and melted, followed by ionization by thermal induction argon/oxygen plasma to produce conformal, nonporous nanocrystalline ZnO films at a growth rate of up to 50 nm/min on amorphous and crystalline substrates including Si (100), fused quartz, glass, muscovite, c- and a-plane sapphire (Al2O3), gold, titanium, and polyimide. X-ray diffraction indicates the grains of as-deposited ZnO to be highly textured, with the fastest growth occurring along the c-axis. The individual grains are observed to be faceted by (103) planes which are the slowest growth planes. ZnO nanocrystalline films of nominal thicknesses of 200 nm are deposited at substrate temperatures of 330°C and 160°C on metal/ceramic substrates and polymer substrates, respectively. In addition, 20-nm- and 200-nm-thick films are also deposited on quartz substrates for optical characterization. At optical spectra above 375 nm, the measured optical transmittance of a 200-nm-thick ZnO film is greater than 80%, while that of a 20-nm-thick film is close to 100%. For a 200-nm-thick ZnO film with an average grain size of 100 nm, a four-point probe measurement shows electrical conductivity of up to 910 S/m. Annealing of 200-nm-thick ZnO films in 300 sccm pure argon at temperatures ranging from 750°C to 950°C (at homologous temperatures between 0.46 and 0.54) alters the textures and morphologies of the thin film. Based on scanning electron microscope images, higher annealing temperatures appear to restructure the ZnO nanocrystalline films to form nanorods of ZnO due to a combination of grain boundary diffusion and bulk diffusion.PACS: films and coatings, 81.15.-z; nanocrystalline materials, 81.07.Bc; II-VI semiconductors, 81.05.Dz.
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Affiliation(s)
- Joachim D Pedersen
- School of Engineering, San Francisco State University, San Francisco, CA, USA
| | - Heather J Esposito
- School of Engineering, San Francisco State University, San Francisco, CA, USA
| | - Kwok Siong Teh
- School of Engineering, San Francisco State University, San Francisco, CA, USA
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