The Experts below are selected from a list of 4311 Experts worldwide ranked by ideXlab platform

Satish Nagarajaiah - One of the best experts on this subject based on the ideXlab platform.

  • noncontact strain mapping using laser induced fluorescence from nanotube based Smart Skin
    Journal of Structural Engineering-asce, 2019
    Co-Authors: Peng Sun, S. M. Bachilo, Chingwei Lin, Bruce R Weisman, Satish Nagarajaiah
    Abstract:

    AbstractStress fields around structural discontinuities such as cracks usually cause complex but distinct strain contours/maps when structures are subjected to load. Hence, mechanical strain on str...

  • Strain-Sensing Smart Skin: A Noncontact Optical Strain Sensor Using Single-Walled Carbon Nanotubes
    Innovative Developments of Advanced Multifunctional Nanocomposites in Civil and Structural Engineering, 2016
    Co-Authors: Satish Nagarajaiah, R. Bruce Weisman, S. M. Bachilo, Peng Sun, Yongchao Yang
    Abstract:

    A novel noncontact strain measurement technology is developed in which single-walled carbon nanotubes (SWCNTs) serve as sensors. This approach exploits the characteristic near-infrared fluorescence signatures of semiconducting SWCNTs, which systematically shift in wavelength when the nanotubes are axially strained. A strain-sensing Smart Skin ("S4") is prepared by coating the surface to be monitored with a thin film of a composite containing well-dispersed SWCNTs embedded in a polymeric host. Strain in the substrate is transmitted through the polymer to the nanotubes, causing systematic and predictable spectral shifts of the nanotube near-infrared fluorescence peak wavelengths. This promising new method should allow quick and precise strain measurements at any position and along any direction of the substrate.

  • Carbon nanotubes as non-contact optical strain sensors in Smart Skins
    The Journal of Strain Analysis for Engineering Design, 2015
    Co-Authors: Peng Sun, R. Bruce Weisman, S. M. Bachilo, Satish Nagarajaiah
    Abstract:

    Progress is reported in the development of a novel non-contact strain measurement technology in which the sensors are single-walled carbon nanotubes. This approach exploits the characteristic short-wave infrared fluorescence signatures of semiconducting single-walled carbon nanotubes and the systematic shifts of their fluorescence wavelengths when the nanotubes are axially strained. A strain-sensing Smart Skin is prepared by coating the surface to be monitored with a thin film of a composite containing well-dispersed single-walled carbon nanotubes embedded in a urethane varnish host. Strain in the surface transfers through the host polymer to the embedded nanotubes. The nanotube strains are then quantitatively monitored by exciting the region of interest with a visible laser beam and capturing and analyzing the resulting single-walled carbon nanotube fluorescence spectrum. High-quality spectra are shown for strain-sensing Smart Skin films in which the nanotubes were pre-processed by selective extraction w...

  • "Smart Skin" optical strain sensor using single wall carbon nanotubes
    SPIE Smart Structures and Materials+ Nondestructive Evaluation and Health Monitoring, 2014
    Co-Authors: Peng Sun, R. Bruce Weisman, S. M. Bachilo, Ji-hoon Kim, Satish Nagarajaiah
    Abstract:

    Strain measurements are essential in structural health monitoring. Traditional strain gages require physical contact between the sensor and read-out device, perturb the surface being monitored, and allow measurement only at the specific location and orientation axis of the sensor. We demonstrate a novel non-contact, multi- point, multi-directional strain sensing approach that overcomes these limitations. In our method, the surface is coated with a thin film of "Smart Skin" containing individualized single-walled carbon nanotubes in a polymeric host. After curing, substrate strains are transmitted through the polymer film to embedded nanotubes. This induces axial strains in the nanotubes, systematically shifting the wavelengths of their characteristic near-infrared fluorescence peaks. To measure strain, a visible laser excites nanotubes at points of interest on the surface, and the near-infrared emission is collected and spectrally analyzed. Observed spectral shifts reveal quantitative strain values. Laboratory tests show sensitivity down to ~400µm, limited by mechanical properties of the polymeric host film. We also vary excitation beam polarization to find the axis of substrate strain. Our method provides spatial resolution down to its gage length of ~100µm. Because the entire substrate is coated with nanoscale strain sensors, measurements can be made at arbitrary locations to construct a full strain map. We will describe recent Smart Skin refinements involving selection of polymer host, nanotube surfactant, nanotube dispersion method, and preparation protocol. Finally, we characterize the orientational distribution of nanotubes using a probabilistic model.

M.m. Manos M. Tentzeris - One of the best experts on this subject based on the ideXlab platform.

  • Nanostructured miniaturized artificial magnetic conductors (AMC) for high-performance antennas in 5G, IoT, and Smart Skin applications
    2017 IEEE 17th International Conference on Nanotechnology (IEEE-NANO), 2017
    Co-Authors: Tong-hong Lin, Atom Watanabe, Venky Sundaram, Rao Tummala, Markondeya P Raj, M.m. Manos M. Tentzeris
    Abstract:

    The emergence of fan-out packaging for 5G and IoT applications has brought escalating performance concerns that arise from the proximity of radiating components such as antennas to lossy materials such as metals and silicon. These concerns also arise in wearable (“Smart Skin”) electronics where the human tissues act as the lossy substrate. Artificial magnetic conductors (AMC) are widely explored for enhancing the performance of antennas that are in close proximity to metallic surfaces and other lossy substrates such as silicon and human tissue. High-permittivity or high-permeability materials can be used to significantly reduce the sizes of AMCs. Nanostructured materials provide unique opportunities to provide stable properties up to the GHz and mm-Wave frequency ranges. In this paper, novel miniaturized nanostructured AMCs utilizing Barium Strontium Titanate (BST) thinfilms and ceramic-polymer composites are demonstrated through full-wave modeling analysis. The size reduction rates are 50.6 % when using 3 μm of BST thinfilm and 77 % when using 400 μm of ceramic-polymer composites. This concept can be further extended with high-permeability magnetic films, and thicker nanocomposite films to achieve further size and performance improvement for a variety of frequency bands and applications.

  • Smart Skins: Could they be the ultimate sensing tool? Today\uFFFDs industry and personal medical care both strongly demand accurate, reliable, robust, lo
    IEEE Nanotechnology Magazine, 2015
    Co-Authors: Taoran Le, Ziyin Lin, Ching-ping Wong, M.m. Manos M. Tentzeris
    Abstract:

    Today's industry and personal medical care both strongly demand accurate, reliable, robust, low-power, and low-cost methods to sense changes in the environment and the condition of the body. This is where the concept of Smart Skin comes in. Smart Skins can monitor changes in environmental parameters, such as temperature, strain, and the presence of ambient gas, and communicate. The Smart Skin concept can also be extended to that of wearable electronic devices for continuous monitoring and reporting of critical biosignals. There are a lot of challenges for the state of the art of Smart Skin, such as expensive fabrication methods, a lack of flexibility and mobility, and the large area fabrication method.

  • Inkjet-printed 'Zero-Power' wireless sensor and power management nodes for IoT and 'Smart Skin' applications
    2014 31th URSI General Assembly and Scientific Symposium URSI GASS 2014, 2014
    Co-Authors: Anya Traille, Y Kawahara, Apostolos Georgiadis, Ana Collado, Hervé Aubert, M.m. Manos M. Tentzeris
    Abstract:

    Nanotechnology and inkjet-printed flexible electronics, sensor and power management (PMU) nodes fabricated on paper, plastic and other polymer substrates are introduced as a sustainable ultra-low-cost solution for the first paradigms of Internet of Things (IoT), “Smart Skins” and “Zero-Power” applications. The paper will cover examples from the state-of-the-art of fully integrated wireless sensor modules on paper or flexible polymers. We will demonstrate numerous 3D multilayer paper-based and LCP-based RF/Microwave Structures that include embedded energy harvesters and PMU's, that could potentially set the foundation for the truly convergent batteryless wireless Internet-of-Things networks of the future with enhanced cognitive intelligence and “zero-power” operability through ambient energy harvesting. Examples from wearable (e.g.biomonitoring) antennas and RF modules will be reported, as well as the first integration of inkjet-printed nanotechnology-based (e.g.CNT, graphene) sensors on paper and organic substrates. The talk will close with a discussion about the challenges for inkjet-printed high-complexity modules as future directions in the area of environmentally-friendly (“green”) RF electronics and “Smart house” conformal IoT topologies.

  • Antenna-based Smart Skin sensors for sustainable, wireless sensor networks
    2012 IEEE International Conference on Industrial Technology ICIT 2012 Proceedings, 2012
    Co-Authors: Hoseon Lee, Trang Thai, Vasileios Lakafosis, Xiaohua Yi, George Shaker, Sangkil Kim, Rushi Vyas, M.m. Manos M. Tentzeris
    Abstract:

    This paper introduces antenna-based “Smart Skin” sensors that are integrated with RFIDs for wireless sensor networks. Furthermore, the paper shows wireless energy harvesting capabilities to enable battery-less, or sustainable, wireless sensor networks with “Smart Skin” sensor nodes. These sensors are highly applicable for industrial applications: carbon-nanotube-based gas sensor, pressure sensor, and strain sensor. The low-profile, flexible sensors can be attached to surfaces as a “Smart Skin” with various sensing capabilities. These antenna-based sensors have the unique property of having a dual function of sensing and communication within a single device, which thereby enables RFID functionality to be integrated. Utilizing wireless sensor networking, it is possible to increase range and area of sensing. All prototypes have been designed, fabricated, and measured, the results of which show high sensitivity.

  • Passive low-cost inkjet-printed Smart Skin sensor for structural health monitoring
    IET Microwaves Antennas & Propagation, 2012
    Co-Authors: B.s. Cook, Atif Shamim, M.m. Manos M. Tentzeris
    Abstract:

    Monitoring fatigue cracking of large engineering structures is a costly and time-intensive process. The authors' present the first low-cost inkjet-printed patch antenna sensor that can passively detect crack formation, orientation and shape by means of resonant frequency shifts in the two resonant modes of the antenna. For the first time, the effect of non-linear crack shapes on the parallel and perpendicular resonant modes of a patch antenna is quantified with simulation and measurement. This study presents a step towards fully integrated, low-cost, conformal and environmentally friendly Smart Skins for real-time monitoring of large structures.

Peng Sun - One of the best experts on this subject based on the ideXlab platform.

  • noncontact strain mapping using laser induced fluorescence from nanotube based Smart Skin
    Journal of Structural Engineering-asce, 2019
    Co-Authors: Peng Sun, S. M. Bachilo, Chingwei Lin, Bruce R Weisman, Satish Nagarajaiah
    Abstract:

    AbstractStress fields around structural discontinuities such as cracks usually cause complex but distinct strain contours/maps when structures are subjected to load. Hence, mechanical strain on str...

  • Strain-Sensing Smart Skin: A Noncontact Optical Strain Sensor Using Single-Walled Carbon Nanotubes
    Innovative Developments of Advanced Multifunctional Nanocomposites in Civil and Structural Engineering, 2016
    Co-Authors: Satish Nagarajaiah, R. Bruce Weisman, S. M. Bachilo, Peng Sun, Yongchao Yang
    Abstract:

    A novel noncontact strain measurement technology is developed in which single-walled carbon nanotubes (SWCNTs) serve as sensors. This approach exploits the characteristic near-infrared fluorescence signatures of semiconducting SWCNTs, which systematically shift in wavelength when the nanotubes are axially strained. A strain-sensing Smart Skin ("S4") is prepared by coating the surface to be monitored with a thin film of a composite containing well-dispersed SWCNTs embedded in a polymeric host. Strain in the substrate is transmitted through the polymer to the nanotubes, causing systematic and predictable spectral shifts of the nanotube near-infrared fluorescence peak wavelengths. This promising new method should allow quick and precise strain measurements at any position and along any direction of the substrate.

  • Carbon nanotubes as non-contact optical strain sensors in Smart Skins
    The Journal of Strain Analysis for Engineering Design, 2015
    Co-Authors: Peng Sun, R. Bruce Weisman, S. M. Bachilo, Satish Nagarajaiah
    Abstract:

    Progress is reported in the development of a novel non-contact strain measurement technology in which the sensors are single-walled carbon nanotubes. This approach exploits the characteristic short-wave infrared fluorescence signatures of semiconducting single-walled carbon nanotubes and the systematic shifts of their fluorescence wavelengths when the nanotubes are axially strained. A strain-sensing Smart Skin is prepared by coating the surface to be monitored with a thin film of a composite containing well-dispersed single-walled carbon nanotubes embedded in a urethane varnish host. Strain in the surface transfers through the host polymer to the embedded nanotubes. The nanotube strains are then quantitatively monitored by exciting the region of interest with a visible laser beam and capturing and analyzing the resulting single-walled carbon nanotube fluorescence spectrum. High-quality spectra are shown for strain-sensing Smart Skin films in which the nanotubes were pre-processed by selective extraction w...

  • "Smart Skin" optical strain sensor using single wall carbon nanotubes
    SPIE Smart Structures and Materials+ Nondestructive Evaluation and Health Monitoring, 2014
    Co-Authors: Peng Sun, R. Bruce Weisman, S. M. Bachilo, Ji-hoon Kim, Satish Nagarajaiah
    Abstract:

    Strain measurements are essential in structural health monitoring. Traditional strain gages require physical contact between the sensor and read-out device, perturb the surface being monitored, and allow measurement only at the specific location and orientation axis of the sensor. We demonstrate a novel non-contact, multi- point, multi-directional strain sensing approach that overcomes these limitations. In our method, the surface is coated with a thin film of "Smart Skin" containing individualized single-walled carbon nanotubes in a polymeric host. After curing, substrate strains are transmitted through the polymer film to embedded nanotubes. This induces axial strains in the nanotubes, systematically shifting the wavelengths of their characteristic near-infrared fluorescence peaks. To measure strain, a visible laser excites nanotubes at points of interest on the surface, and the near-infrared emission is collected and spectrally analyzed. Observed spectral shifts reveal quantitative strain values. Laboratory tests show sensitivity down to ~400µm, limited by mechanical properties of the polymeric host film. We also vary excitation beam polarization to find the axis of substrate strain. Our method provides spatial resolution down to its gage length of ~100µm. Because the entire substrate is coated with nanoscale strain sensors, measurements can be made at arbitrary locations to construct a full strain map. We will describe recent Smart Skin refinements involving selection of polymer host, nanotube surfactant, nanotube dispersion method, and preparation protocol. Finally, we characterize the orientational distribution of nanotubes using a probabilistic model.

Yu Wang - One of the best experts on this subject based on the ideXlab platform.

  • a mechatronic Smart Skin of flight vehicle structures for impact monitoring of light weight and low power consumption
    Mechanical Systems and Signal Processing, 2020
    Co-Authors: Yu Wang, Shenfang Yuan
    Abstract:

    Abstract This paper proposes a mechatronic Smart Skin (MSS) that has the ability to perform large-scale impact monitoring of flight vehicle structures with light weight and low-power consumption. The MSS is a complete mechatronic system that can acquire and process impact response signals and record impact results by itself. The MSS is achieved by integrating a large-scale flexible electronic network system (ENS) with a Skin structure. The ENS is not just an ordinary piezoelectric sensor (referred as PZT) network but a complete impact monitoring network system, including a large-scale PZT network and a flexible impact monitoring system (FIMS) that is lightweight and exhibits low power consumption. The ENS can be easily manufactured by using a flexible printing circuit process that is commonly available at a low cost. In this paper, the principle and design of the MSS and the FIMS are first proposed. Then, an aircraft composite Skin with several stiffeners is used as an example to achieve and validate a MSS. According to the validation results, the impact monitoring correctness of the MSS reaches 95%, and the additional weight and power consumption of the MSS introduced by the ENS are lower than 55 g/m2 and 48 mW/m2, respectively.

  • Simulation Method of an Expandable Lamb Wave Sensor Network for Aircraft Smart Skin
    IEEE Sensors Journal, 2020
    Co-Authors: Yu Wang
    Abstract:

    In order to realize a large-scale and lightweight Lamb wave sensor network, which is important to develop aircraft Smart Skin for Structural Health Monitoring (SHM), the expandable sensor network based on the island-interconnect design is a feasible way. However, the analysis of mechanical properties and expandability is the key point to design such sensor network. In this paper, the simulation method of thin island-interconnect structures with arbitrary shape is proposed based on ABAQUS. It includes two key parts. The first is buckling mode analysis to extract buckling modes and corresponding eigenvalues of the structure. The second is postbuckling behavior analysis to analyze mechanical properties of the structure under large tensile deformation, based on a certain buckling mode. The simulation method is not limited by the manufacturing process and can be combined with micro- or nano-manufacturing process or conventional Flexible Printed Circuit (FPC) process. Three simulation cases are given and analyzed, including serpentine, serpentine-based fractal and irregular island-interconnect structure. Based on the fractal island-interconnect structure, an expandable Lamb wave sensor network is designed and manufactured by the FPC process for validation of the simulation method. Results of the tensile test show good agreements with the simulation results. And the sensor network can be applied to Lamb wave-based SHM. The simulation method can provide an effective analysis tool and guidance for further design of expandable sensor networks.

  • A piezoelectric sensor network with shared signal transmission wires for structural health monitoring of aircraft Smart Skin
    Mechanical Systems and Signal Processing, 2020
    Co-Authors: Yu Wang, Lei Qiu, Yijie Luo, Rui Ding, Fei Jiang
    Abstract:

    Abstract Aircraft Smart Skin needs to integrate a large number of piezoelectric (PZT) elements and wires for structural health monitoring (SHM), which not only add considerable weight to aircraft structures, but also occupy a lot of monitoring channels, making the monitoring system complex. To study this issue, this paper proposed the design method of a PZT sensor network with shared signal transmission wires and its passive and active SHM methods. The design principle is that one electrode of each PZT in the same column are connected by the same wire and the other electrode of each PZT in the same row are connected by the same wire. Compared with a conventional M × N PZT sensor network, which requires at least M × N wires, the proposed PZT sensor network with shared signal transmission wires only requires M + N wires without increasing PZTs. A 7 × 7 PZT Layer with shared signal transmission wires is designed and manufactured by the Flexible Printed Circuit (FPC) process to further reduce the weight. The PZT Layer with an effective monitoring region of 780 mm × 780 mm is co-cured onto a glass fiber reinforced plate for verification. Experimental results show that the PZT Layer can accurately detect structural impact and damage regions based on the SHM methods, demonstrating that the proposed PZT sensor network with shared signal transmission wires can significantly reduce the number of wires and monitoring channels and has great potential in aircraft Smart Skin applications for both passive and active SHM.

  • A stretchable and large-scale guided wave sensor network for aircraft Smart Skin of structural health monitoring:
    Structural Health Monitoring, 2019
    Co-Authors: Yu Wang, Lei Qiu, Yijie Luo, Rui Ding
    Abstract:

    Aircraft Smart Skin technology requires the integration of large-scale, lightweight, and integrative sensor networks with aircraft structural Skin, but it is difficult to directly manufacture such ...

S. M. Bachilo - One of the best experts on this subject based on the ideXlab platform.

  • noncontact strain mapping using laser induced fluorescence from nanotube based Smart Skin
    Journal of Structural Engineering-asce, 2019
    Co-Authors: Peng Sun, S. M. Bachilo, Chingwei Lin, Bruce R Weisman, Satish Nagarajaiah
    Abstract:

    AbstractStress fields around structural discontinuities such as cracks usually cause complex but distinct strain contours/maps when structures are subjected to load. Hence, mechanical strain on str...

  • Strain-Sensing Smart Skin: A Noncontact Optical Strain Sensor Using Single-Walled Carbon Nanotubes
    Innovative Developments of Advanced Multifunctional Nanocomposites in Civil and Structural Engineering, 2016
    Co-Authors: Satish Nagarajaiah, R. Bruce Weisman, S. M. Bachilo, Peng Sun, Yongchao Yang
    Abstract:

    A novel noncontact strain measurement technology is developed in which single-walled carbon nanotubes (SWCNTs) serve as sensors. This approach exploits the characteristic near-infrared fluorescence signatures of semiconducting SWCNTs, which systematically shift in wavelength when the nanotubes are axially strained. A strain-sensing Smart Skin ("S4") is prepared by coating the surface to be monitored with a thin film of a composite containing well-dispersed SWCNTs embedded in a polymeric host. Strain in the substrate is transmitted through the polymer to the nanotubes, causing systematic and predictable spectral shifts of the nanotube near-infrared fluorescence peak wavelengths. This promising new method should allow quick and precise strain measurements at any position and along any direction of the substrate.

  • Carbon nanotubes as non-contact optical strain sensors in Smart Skins
    The Journal of Strain Analysis for Engineering Design, 2015
    Co-Authors: Peng Sun, R. Bruce Weisman, S. M. Bachilo, Satish Nagarajaiah
    Abstract:

    Progress is reported in the development of a novel non-contact strain measurement technology in which the sensors are single-walled carbon nanotubes. This approach exploits the characteristic short-wave infrared fluorescence signatures of semiconducting single-walled carbon nanotubes and the systematic shifts of their fluorescence wavelengths when the nanotubes are axially strained. A strain-sensing Smart Skin is prepared by coating the surface to be monitored with a thin film of a composite containing well-dispersed single-walled carbon nanotubes embedded in a urethane varnish host. Strain in the surface transfers through the host polymer to the embedded nanotubes. The nanotube strains are then quantitatively monitored by exciting the region of interest with a visible laser beam and capturing and analyzing the resulting single-walled carbon nanotube fluorescence spectrum. High-quality spectra are shown for strain-sensing Smart Skin films in which the nanotubes were pre-processed by selective extraction w...

  • "Smart Skin" optical strain sensor using single wall carbon nanotubes
    SPIE Smart Structures and Materials+ Nondestructive Evaluation and Health Monitoring, 2014
    Co-Authors: Peng Sun, R. Bruce Weisman, S. M. Bachilo, Ji-hoon Kim, Satish Nagarajaiah
    Abstract:

    Strain measurements are essential in structural health monitoring. Traditional strain gages require physical contact between the sensor and read-out device, perturb the surface being monitored, and allow measurement only at the specific location and orientation axis of the sensor. We demonstrate a novel non-contact, multi- point, multi-directional strain sensing approach that overcomes these limitations. In our method, the surface is coated with a thin film of "Smart Skin" containing individualized single-walled carbon nanotubes in a polymeric host. After curing, substrate strains are transmitted through the polymer film to embedded nanotubes. This induces axial strains in the nanotubes, systematically shifting the wavelengths of their characteristic near-infrared fluorescence peaks. To measure strain, a visible laser excites nanotubes at points of interest on the surface, and the near-infrared emission is collected and spectrally analyzed. Observed spectral shifts reveal quantitative strain values. Laboratory tests show sensitivity down to ~400µm, limited by mechanical properties of the polymeric host film. We also vary excitation beam polarization to find the axis of substrate strain. Our method provides spatial resolution down to its gage length of ~100µm. Because the entire substrate is coated with nanoscale strain sensors, measurements can be made at arbitrary locations to construct a full strain map. We will describe recent Smart Skin refinements involving selection of polymer host, nanotube surfactant, nanotube dispersion method, and preparation protocol. Finally, we characterize the orientational distribution of nanotubes using a probabilistic model.