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Diao Y, Zhang Y, Li Y, Jiang J. Metal-Oxide Heterojunction: From Material Process to Neuromorphic Applications. SENSORS (BASEL, SWITZERLAND) 2023; 23:9779. [PMID: 38139625 PMCID: PMC10747618 DOI: 10.3390/s23249779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Revised: 11/30/2023] [Accepted: 12/05/2023] [Indexed: 12/24/2023]
Abstract
As technologies like the Internet, artificial intelligence, and big data evolve at a rapid pace, computer architecture is transitioning from compute-intensive to memory-intensive. However, traditional von Neumann architectures encounter bottlenecks in addressing modern computational challenges. The emulation of the behaviors of a synapse at the device level by ionic/electronic devices has shown promising potential in future neural-inspired and compact artificial intelligence systems. To address these issues, this review thoroughly investigates the recent progress in metal-oxide heterostructures for neuromorphic applications. These heterostructures not only offer low power consumption and high stability but also possess optimized electrical characteristics via interface engineering. The paper first outlines various synthesis methods for metal oxides and then summarizes the neuromorphic devices using these materials and their heterostructures. More importantly, we review the emerging multifunctional applications, including neuromorphic vision, touch, and pain systems. Finally, we summarize the future prospects of neuromorphic devices with metal-oxide heterostructures and list the current challenges while offering potential solutions. This review provides insights into the design and construction of metal-oxide devices and their applications for neuromorphic systems.
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Affiliation(s)
| | | | | | - Jie Jiang
- Hunan Key Laboratory of Nanophotonics and Devices, School of Physics, Central South University, 932 South Lushan Road, Changsha 410083, China
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2
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Sengupta D, Lu L, Gomes DR, Jayawardhana B, Pei Y, Kottapalli AGP. Fabric-like Electrospun PVAc-Graphene Nanofiber Webs as Wearable and Degradable Piezocapacitive Sensors. ACS APPLIED MATERIALS & INTERFACES 2023; 15:22351-22366. [PMID: 37098157 PMCID: PMC10176318 DOI: 10.1021/acsami.3c03113] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Flexible piezocapacitive sensors utilizing nanomaterial-polymer composite-based nanofibrous membranes offer an attractive alternative to more traditional piezoelectric and piezoresistive wearable sensors owing to their ultralow powered nature, fast response, low hysteresis, and insensitivity to temperature change. In this work, we propose a facile method of fabricating electrospun graphene-dispersed PVAc nanofibrous membrane-based piezocapacitive sensors for applications in IoT-enabled wearables and human physiological function monitoring. A series of electrical and material characterization experiments were conducted on both the pristine and graphene-dispersed PVAc nanofibers to understand the effect of graphene addition on nanofiber morphology, dielectric response, and pressure sensing performance. Dynamic uniaxial pressure sensing performance evaluation tests were conducted on the pristine and graphene-loaded PVAc nanofibrous membrane-based sensors for understanding the effect of two-dimensional (2D) nanofiller addition on pressure sensing performance. A marked increase in the dielectric constant and pressure sensing performance was observed for graphene-loaded spin coated membrane and nanofiber webs respectively, and subsequently the micro dipole formation model was invoked to explain the nanofiller-induced dielectric constant enhancement. The robustness and reliability of the sensor have been underscored by conducting accelerated lifetime assessment experiments entailing at least 3000 cycles of periodic tactile force loading. A series of tests involving human physiological parameter monitoring were conducted to underscore the applicability of the proposed sensor for IoT-enabled personalized health care, soft robotics, and next-generation prosthetic devices. Finally, the easy degradability of the sensing elements is demonstrated to emphasize their suitability for transient electronics applications.
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Affiliation(s)
- Debarun Sengupta
- Department of Advanced Production Engineering (APE), Engineering and Technology Institute Groningen (ENTEG), University of Groningen, Groningen 9747 AG, The Netherlands
| | - Liqiang Lu
- Department of Advanced Production Engineering (APE), Engineering and Technology Institute Groningen (ENTEG), University of Groningen, Groningen 9747 AG, The Netherlands
| | - Diego Ribas Gomes
- Department of Advanced Production Engineering (APE), Engineering and Technology Institute Groningen (ENTEG), University of Groningen, Groningen 9747 AG, The Netherlands
| | - Bayu Jayawardhana
- Department of Discrete Technology and Production Automation, Engineering and Technology Institute Groningen, Faculty of Science and Engineering, University of Groningen, Groningen 9747 AG, The Netherlands
| | - Yutao Pei
- Department of Advanced Production Engineering (APE), Engineering and Technology Institute Groningen (ENTEG), University of Groningen, Groningen 9747 AG, The Netherlands
| | - Ajay Giri Prakash Kottapalli
- Department of Advanced Production Engineering (APE), Engineering and Technology Institute Groningen (ENTEG), University of Groningen, Groningen 9747 AG, The Netherlands
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3
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Kim KL, Cho SH, Lee JB, Kim G, Lee K, Lee SW, Kang HS, Park C, Ahn JH, Shim W, Bae I, Park C. Transparent and Flexible Graphene Pressure Sensor with Self-Assembled Topological Crystalline Ionic Gel. ACS APPLIED MATERIALS & INTERFACES 2023; 15:19319-19329. [PMID: 37022806 DOI: 10.1021/acsami.3c01375] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
This study demonstrates transparent and flexible capacitive pressure sensors using a high-k ionic gel composed of an insulating polymer (poly(vinylidene fluoride-co-trifluoroethylene-co-chlorofluoroethylene), P(VDF-TrFE-CFE)) blended with an ionic liquid (IL; 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) amide, [EMI][TFSA]). The thermal melt recrystallization of the P(VDF-TrFE-CFE):[EMI][TFSA] blend films develops the characteristic topological semicrystalline surface of the films, making them highly sensitive to pressure. Using optically transparent and mechanically flexible graphene electrodes, a novel pressure sensor is realized with the topological ionic gel. The sensor exhibits a sufficiently large air dielectric gap between graphene and the topological ionic gel, resulting in a large variation in capacitance before and after the application of various pressures owing to the pressure-sensitive reduction of the air gap. The developed graphene pressure sensor exhibits a high sensitivity of 10.14 kPa-1 at 20 kPa, rapid response times of <30 ms, and durable device operation with 4000 repeated ON/OFF cycles. Furthermore, broad-range detections from lightweight objects to human motion are successfully achieved, demonstrating that the developed pressure sensor with a self-assembled crystalline topology is potentially suitable for a variety of cost-effective wearable applications.
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Affiliation(s)
- Kang Lib Kim
- Department of Materials Science and Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Sung Hwan Cho
- Department of Materials Science and Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Jae-Bok Lee
- School of Electrical and Electronic Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Gwangmook Kim
- Department of Materials Science and Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Kyuho Lee
- Department of Materials Science and Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Seung Won Lee
- Department of Materials Science and Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Han Sol Kang
- Department of Materials Science and Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Chanho Park
- Department of Materials Science and Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Jong-Hyun Ahn
- School of Electrical and Electronic Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Wooyoung Shim
- Department of Materials Science and Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 03722, Republic of Korea
| | - Insung Bae
- Department of Advanced Materials Engineering, Hannam University, Yuseong-daero 1646, Yuseong-gu, Daejeon 34054, Republic of Korea
| | - Cheolmin Park
- Department of Materials Science and Engineering, Yonsei University, Yonsei-ro 50, Seodaemun-gu, Seoul 03722, Republic of Korea
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4
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Characterization of Silver Nanowire-Based Transparent Electrodes Obtained Using Different Drying Methods. NANOMATERIALS 2022; 12:nano12030461. [PMID: 35159806 PMCID: PMC8838584 DOI: 10.3390/nano12030461] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 01/12/2022] [Accepted: 01/19/2022] [Indexed: 12/02/2022]
Abstract
Metal-based transparent top electrodes allow electronic devices to achieve transparency, thereby expanding their application range. Silver nanowire (AgNW)-based transparent electrodes can function as transparent top electrodes, owing to their excellent conductivity and transmittance. However, they require a high-temperature drying process, which damages the bottom functional layers. Here, we fabricated two types of AgNW-based electrodes using the following three drying methods: thermal, room-temperature, and vacuum. Thereafter, we investigated the variation in their morphological, electrical, and optical characteristics as a function of the drying method and duration. When the AgNW-exposed electrode was dried at room temperature, it exhibited a high surface roughness and low conductivity, owing to the slow solvent evaporation. However, under vacuum, it exhibited a similar electrical conductivity to that achieved by thermal drying because of the decreased solvent boiling point and fast solvent evaporation. Conversely, the AgNW-embedded electrodes exhibited similar roughness values and electrical conductivities regardless of the drying method applied. This was because the polymer shrinkage during the AgNW embedding process generated capillary force and improved the interconnectivity between the nanowires. The AgNW-based electrodes exhibited similar optical properties regardless of the drying method and electrode type. This study reveals that vacuum drying can afford transparent top electrodes without damaging functional layers.
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Liu Z, Wan K, Zhu T, Zhu J, Xu J, Zhang C, Liu T. Superelastic, Fatigue-Resistant, and Flame-Retardant Spongy Conductor for Human Motion Detection against a Harsh High-Temperature Condition. ACS APPLIED MATERIALS & INTERFACES 2021; 13:7580-7591. [PMID: 33541076 DOI: 10.1021/acsami.0c20852] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The construction of wearable piezoresistive sensors with high elasticity, large gauge factor, and excellent durability in a harsh high-temperature environment is highly desired yet challenging. Here, a lightweight, superelastic, and fatigue-resistant spongy conductor was fabricated via a sponge-constrained network assembly, during which highly conductive graphene and flame-retardant montmorillonite were alternatively deposited on a three-dimensional melamine scaffold. The as-obtained spongy conductor exhibited a highly deformation-tolerant conductivity up to 80% strain and excellent fatigue resistance of 10,000 compressive cycles at 70% strain. As a result, the spongy conductor can readily work as a piezoresistive sensor and exhibited a high gauge factor value of ∼2.3 in a strain range of 60-80% and excellent durability under 60% strain for 10,000 cycles without sacrificing its piezoresistive performance. Additionally, the piezoresistive sensor showed great thermal stability up to 250 °C for more than 7 days and sufficient flame-retardant performance for at least 20 s. This lightweight, superelastic, and flame-retardant spongy conductor reveals tremendous potential in human motion detection against a harsh high-temperature environment.
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Affiliation(s)
- Zhichong Liu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Innovation Center for Textile Science and Technology, Donghua University, Shanghai 201620, P. R. China
| | - Kening Wan
- School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, U.K
| | - Tianyi Zhu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Innovation Center for Textile Science and Technology, Donghua University, Shanghai 201620, P. R. China
| | - Jixin Zhu
- Shaanxi Institute of Flexible Electronics (SIFE), Northwestern Polytechnical University (NPU), 127 West Youyi Road, Xi'an 710072, P. R. China
| | - Jingsan Xu
- School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, Queensland 4001, Australia
| | - Chao Zhang
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Innovation Center for Textile Science and Technology, Donghua University, Shanghai 201620, P. R. China
| | - Tianxi Liu
- State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, College of Materials Science and Engineering, Innovation Center for Textile Science and Technology, Donghua University, Shanghai 201620, P. R. China
- Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122, P. R. China
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Kim DH, Jung Y, Jung K, Kwak DH, Park DM, Shin MG, Tak HJ, Ko JS. Hollow polydimethylsiloxane (PDMS) foam with a 3D interconnected network for highly sensitive capacitive pressure sensors. MICRO AND NANO SYSTEMS LETTERS 2020. [DOI: 10.1186/s40486-020-00127-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
AbstractWe propose a highly sensitive capacitive pressure sensor made of hollow polydimethylsiloxane (PDMS) foam with a three-dimensional network structure. The stiffness of the foam is adjusted by the viscosity of the PDMS solution. The fabricated PDMS-30 (PDMS 30 wt%) foam shows extremely high porosity (> 86%) approximately 19 times that of bare PDMS (PDMS 100 wt%) foam. Capacitive pressure sensors fabricated using the foam possess high sensitivity, good compressibility (up to 80% strain), and consistent output characteristics in a 2000-cycle test.
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7
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Son M, Kim H, Jang J, Kim SY, Ki HC, Lee BH, Kim IS, Ham MH. Low-Power Complementary Logic Circuit Using Polymer-Electrolyte-Gated Graphene Switching Devices. ACS APPLIED MATERIALS & INTERFACES 2019; 11:47247-47252. [PMID: 31746181 DOI: 10.1021/acsami.9b16417] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
The modulation of the electrical properties of graphene and its device configurations for low-power consumption are important in developing graphene-based logic electronics. Here, we demonstrate the change in the charge transport in graphene from ambipolar to unipolar using surface charge transfer doping of the polymer electrolyte. Unipolar graphene field-effect transistors (GFETs) were obtained by the surface treatment of poly(acrylic acid) (PAA) for p-type and poly(ethyleneimine) (PEI) for n-type as polymer-electrolyte gates. In addition, lithium perchlorate (LiClO4) in a polymer matrix can be used for the low-gate voltage operation of GFETs (less than ±3 V) because of its high gating efficiency. Using polymer-electrolyte-gated GFETs, complementary graphene inverters were fabricated with a voltage swing of 57% and maximum voltage gain (Vgain) of 1.1 at a low supply voltage (VDD = 1 V). This is expected to facilitate the development of graphene-based logic devices with low-cost, low-power, and flexible electronics.
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Affiliation(s)
- Myungwoo Son
- Photonic Energy Research Center , Korea Photonics Technology Institute (KOPTI) , Cheomdanbencheo-ro 108 beon-gil 9 , Buk-gu, Gwangju 61007 , Republic of Korea
| | | | | | | | - Hyun Chul Ki
- Photonic Energy Research Center , Korea Photonics Technology Institute (KOPTI) , Cheomdanbencheo-ro 108 beon-gil 9 , Buk-gu, Gwangju 61007 , Republic of Korea
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8
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Jang S, Choi D, Yang S, Kwon JY. Thermo and flex multi-functional array ionic sensor for a human adaptive device. RSC Adv 2019; 9:36960-36966. [PMID: 35539088 PMCID: PMC9075219 DOI: 10.1039/c9ra08188g] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 11/06/2019] [Indexed: 11/21/2022] Open
Abstract
Recently, electronic skin that mimics human skin in measuring tactile stimuli, temperature, and humidity and having a self-healing function was developed. Furthermore, with the advances in the field of artificial intelligence and health monitoring, various materials and methods have been studied for e-skin. The limitations to work on actual human skin include device flexibility and large-area applications through array structures, and many studies are underway to overcome these problems. Polymeric materials containing ionic liquids can be used to easily fabricate devices in the solid state. They are highly sensitive to both pressure and temperature, making them suitable for multi-sensing devices. Resistive and capacitive sensors have the advantage of having a simple structure, which makes them easy to fabricate. In a single device, both types work well. For resistive sensors, the temperature sensitivity (1.1/°C) is relatively high. Conversely, capacitive sensors have a low temperature sensitivity (0.3/°C). However, they have the advantage of being uniformly variable under each condition and having a smaller error range. In the array structure, independent flex and thermo sensors are arranged repeatedly. The resistive type shows changes in temperature and bending, but in the capacitive type, it is difficult to obtain results from the pixels due to parasitic capacitance. A multi-functional and array sensor which is important to imitate the real human skin. The ionic thermoplastic polyurethane is deformable and changed electrical characteristics by temperature and pressure.![]()
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Affiliation(s)
- Sukjin Jang
- School of Integrated Technology, Yonsei University Incheon 21983 Republic of Korea .,Yonsei Institute of Convergence Technology, Yonsei University Incheon 21983 Republic of Korea
| | - Daehwan Choi
- School of Integrated Technology, Yonsei University Incheon 21983 Republic of Korea .,Yonsei Institute of Convergence Technology, Yonsei University Incheon 21983 Republic of Korea
| | - Suk Yang
- School of Integrated Technology, Yonsei University Incheon 21983 Republic of Korea .,Yonsei Institute of Convergence Technology, Yonsei University Incheon 21983 Republic of Korea
| | - Jang-Yeon Kwon
- School of Integrated Technology, Yonsei University Incheon 21983 Republic of Korea .,Yonsei Institute of Convergence Technology, Yonsei University Incheon 21983 Republic of Korea
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Jiang S, Yu J, Xiao Y, Zhu Y, Zhang W. Ultrawide Sensing Range and Highly Sensitive Flexible Pressure Sensor Based on a Percolative Thin Film with a Knoll-like Microstructured Surface. ACS APPLIED MATERIALS & INTERFACES 2019; 11:20500-20508. [PMID: 31088081 DOI: 10.1021/acsami.9b02659] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Flexible pressure sensors have attracted considerable research interest and efforts owing to their broad application prospects in wearable devices, health monitoring, and human-machine interfacing. High-sensitivity, wide-workable-range, and low-cost pressure sensors are the primary requirement in practical application. In this work, flexible pressure sensors with high sensitivity in a wide pressure range are constructed by introducing a knoll-like microstructured surface into a percolative thermoplastic polyurethane/carbon black sensitive film, using a facile, efficient, and cost-effective screen-printing route. The prepared pressure sensors exhibit an ultrawide sensing pressure range of 0-1500 kPa, high sensitivity (5.205 kPa-1 in the range of 0-100 kPa and 0.63 kPa-1 over 1200 kPa), fast response, and excellent durability for more than 30 000 cycles. We demonstrated the applications of our pressure sensors in health monitoring, such as detection of wrist radial artery pulse waves, phonation, and vibrations. In addition, the proposed sensors showed the potential in object manipulation and human-machine interfacing, capable of detecting spatial pressure distribution, measuring grip forces, and monitoring gas pressures.
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Affiliation(s)
- Shuwen Jiang
- State Key Laboratory of Electronic Thin Films and Integrated Devices , University of Electronic Science and Technology of China , Chengdu 611731 , China
| | - Jiangtao Yu
- State Key Laboratory of Electronic Thin Films and Integrated Devices , University of Electronic Science and Technology of China , Chengdu 611731 , China
| | - Yao Xiao
- State Key Laboratory of Electronic Thin Films and Integrated Devices , University of Electronic Science and Technology of China , Chengdu 611731 , China
| | - Yangyi Zhu
- State Key Laboratory of Electronic Thin Films and Integrated Devices , University of Electronic Science and Technology of China , Chengdu 611731 , China
| | - Wanli Zhang
- State Key Laboratory of Electronic Thin Films and Integrated Devices , University of Electronic Science and Technology of China , Chengdu 611731 , China
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10
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Yang JC, Kim JO, Oh J, Kwon SY, Sim JY, Kim DW, Choi HB, Park S. Microstructured Porous Pyramid-Based Ultrahigh Sensitive Pressure Sensor Insensitive to Strain and Temperature. ACS APPLIED MATERIALS & INTERFACES 2019; 11:19472-19480. [PMID: 31056895 DOI: 10.1021/acsami.9b03261] [Citation(s) in RCA: 161] [Impact Index Per Article: 32.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
An ultrahigh sensitive capacitive pressure sensor based on a porous pyramid dielectric layer (PPDL) is reported. Compared to that of the conventional pyramid dielectric layer, the sensitivity was drastically increased to 44.5 kPa-1 in the pressure range <100 Pa, an unprecedented sensitivity for capacitive pressure sensors. The enhanced sensitivity is attributed to a lower compressive modulus and larger change in an effective dielectric constant under pressure. By placing the pressure sensors on islands of hard elastomer embedded in a soft elastomer substrate, the sensors exhibited insensitivity to strain. The pressure sensors were also nonresponsive to temperature. Finally, a contact resistance-based pressure sensor is also demonstrated by chemically grafting PPDL with a conductive polymer, which also showed drastically enhanced sensitivity.
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Affiliation(s)
- Jun Chang Yang
- Department of Materials Science and Engineering , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , Republic of Korea
| | - Jin-Oh Kim
- Department of Materials Science and Engineering , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , Republic of Korea
| | - Jinwon Oh
- Department of Materials Science and Engineering , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , Republic of Korea
| | - Se Young Kwon
- Department of Materials Science and Engineering , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , Republic of Korea
| | - Joo Yong Sim
- Bio-Medical IT Convergence Research Department , Electronics and Telecommunications Research Institute (ETRI) , Daejeon 34129 , Republic of Korea
| | - Da Won Kim
- Department of Materials Science and Engineering , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , Republic of Korea
| | - Han Byul Choi
- Department of Materials Science and Engineering , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , Republic of Korea
| | - Steve Park
- Department of Materials Science and Engineering , Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141 , Republic of Korea
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11
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Yang J, Luo S, Zhou X, Li J, Fu J, Yang W, Wei D. Flexible, Tunable, and Ultrasensitive Capacitive Pressure Sensor with Microconformal Graphene Electrodes. ACS APPLIED MATERIALS & INTERFACES 2019; 11:14997-15006. [PMID: 30869860 DOI: 10.1021/acsami.9b02049] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
High-performance flexible pressure sensors are highly desirable in health monitoring, robotic tactile, and artificial intelligence. Construction of microstructures in dielectrics and electrodes is the dominating approach to improving the performance of capacitive pressure sensors. Herein, we have demonstrated a novel three-dimensional microconformal graphene electrode for ultrasensitive and tunable flexible capacitive pressure sensors. Because the fabrication process is controllable, the morphologies of the graphene that is perfectly conformal with the electrode are controllable consequently. Multiscale morphologies ranging from a few nanometers to hundreds of nanometers, even to tens of micrometers, have been systematically investigated, and the high-performance capacitive pressure sensor with high sensitivity (3.19 kPa-1), fast response (30 ms), ultralow detection limit (1 mg), tunable-sensitivity, high flexibility, and high stability was obtained. Furthermore, an ultrasensitivity of 7.68 kPa-1 was successfully achieved via symmetric double microconformal graphene electrodes. The finite element analysis indicates that the microstructured graphene electrode can enhance large deformation and thus effectively improve the sensitivity. Additionally, the proposed pressure sensors are demonstrated with practical applications including insect crawling detection, wearable health monitoring, and force feedback of robot tactile sensing with a sensor array. The microconformal graphene may provide a new approach to fabricating controllable microstructured electrodes to enhance the performance of capacitive pressure sensors and has great potential for innovative applications in wearable health-monitoring devices, robot tactile systems, and human-machine interface systems.
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Affiliation(s)
- Jun Yang
- Chongqing Key Laboratory of Multi-Scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology , Chinese Academy of Sciences , Chongqing 400714 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Shi Luo
- Chongqing Key Laboratory of Multi-Scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology , Chinese Academy of Sciences , Chongqing 400714 , P. R. China
| | - Xi Zhou
- Chongqing Key Laboratory of Multi-Scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology , Chinese Academy of Sciences , Chongqing 400714 , P. R. China
| | - Jialu Li
- Chongqing Key Laboratory of Multi-Scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology , Chinese Academy of Sciences , Chongqing 400714 , P. R. China
| | - Jianting Fu
- Chongqing Key Laboratory of Multi-Scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology , Chinese Academy of Sciences , Chongqing 400714 , P. R. China
| | - Weidong Yang
- Department of Materials Science and Engineering , National University of Singapore , Singapore 117576 , Singapore
| | - Dapeng Wei
- Chongqing Key Laboratory of Multi-Scale Manufacturing Technology, Chongqing Institute of Green and Intelligent Technology , Chinese Academy of Sciences , Chongqing 400714 , P. R. China
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12
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Abstract
Flexible sensors have the potential to be seamlessly applied to soft and irregularly shaped surfaces such as the human skin or textile fabrics. This benefits conformability dependant applications including smart tattoos, artificial skins and soft robotics. Consequently, materials and structures for innovative flexible sensors, as well as their integration into systems, continue to be in the spotlight of research. This review outlines the current state of flexible sensor technologies and the impact of material developments on this field. Special attention is given to strain, temperature, chemical, light and electropotential sensors, as well as their respective applications.
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13
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Ma Z, Li S, Wang H, Cheng W, Li Y, Pan L, Shi Y. Advanced electronic skin devices for healthcare applications. J Mater Chem B 2018; 7:173-197. [PMID: 32254546 DOI: 10.1039/c8tb02862a] [Citation(s) in RCA: 73] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Electronic skin, a kind of flexible electronic device and system inspired by human skin, has emerged as a promising candidate for wearable personal healthcare applications. Wearable electronic devices with skin-like properties will provide platforms for continuous and real-time monitoring of human physiological signals such as tissue pressure, body motion, temperature, metabolites, electrolyte balance, and disease-related biomarkers. Transdermal drug delivery devices can also be integrated into electronic skin to enhance its non-invasive, real-time dynamic therapy functions. This review summarizes the recent progress in electronic skin devices for applications in human health monitoring and therapy systems as well as several potential mass production technologies such as inkjet printing and 3D printing. The opportunities and challenges in broadening the applications of electronic skin devices in practical healthcare are also discussed.
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Affiliation(s)
- Zhong Ma
- Collaborative Innovation Center of Advanced Microstructures, Jiangsu Provincial Key Laboratory of Photonic and Electronic Materials, School of Electronic Science and Engineering, Nanjing University, 210093 Nanjing, China.
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