Heat Transfer Spectroscopy and “Heat Transfer-Distance” Curves

2008 ◽  
Author(s):  
Arvind Narayanaswamy ◽  
Sheng Shen ◽  
Gang Chen
Keyword(s):  
Heat Transfer ◽  
Radiative Transfer ◽  
Atomic Force Microscope ◽  
Near Field ◽  
Surface Force ◽  
Casimir Forces ◽  
Distance Curve ◽  
Transfer Distance ◽  
Atomic Force ◽  
Order Of Magnitude

Thermal radiative transfer between objects as well as near-field forces such as van der Waals or Casimir forces have their origins in the fluctuations of the electrodynamic field. Near-field radiative transfer between two objects can be enhanced by a few order of magnitude compared to the far-field radiative transfer that can be described by Planck’s theory of blackbody radiation and Kirchoff’s laws. Despite this common origin, experimental techniques of measuring near-field forces (using the surface force apparatus and the atomic force microscope) are more sophisticated than techniques of measuring near-field radiative transfer. In this work, we present an ultra-sensitive experimental technique of measuring near-field using a bi-material atomic force microscope cantilever as the thermal sensor. Just as measurements of near-field forces results in a “force distance curve”, measurement of near-field radiative transfer results in a “heat transfer-distance” curve. Results from the measurement of near-field radiative transfer will be presented.

scholarly journals A Survey of NFC Sensors Based on Energy Harvesting for IoT Applications

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3746 ◽  
Author(s):  
Antonio Lazaro ◽  
Ramon Villarino ◽  
David Girbau
Keyword(s):  
Energy Harvesting ◽  
Integrated Circuits ◽  
Radio Frequency Identification ◽  
Low Cost ◽  
Near Field ◽  
Wearable Sensors ◽  
Cold Chain ◽  
Iot Applications ◽  
Wide Range ◽  
Frequency Identification

In this article, an overview of recent advances in the field of battery-less near-field communication (NFC) sensors is provided, along with a brief comparison of other short-range radio-frequency identification (RFID) technologies. After reviewing power transfer using NFC, recommendations are made for the practical design of NFC-based tags and NFC readers. A list of commercial NFC integrated circuits with energy-harvesting capabilities is also provided. Finally, a survey of the state of the art in NFC-based sensors is presented, which demonstrates that a wide range of sensors (both chemical and physical) can be used with this technology. Particular interest arose in wearable sensors and cold-chain traceability applications. The availability of low-cost devices and the incorporation of NFC readers into most current mobile phones make NFC technology key to the development of green Internet of Things (IoT) applications.

Non-Surface Polaritonic Peaks in Near-Field Radiative Transfer

2014 ◽  
Author(s):  
Braden Czapla ◽  
Yi Zheng ◽  
Karthik Sasihithlu ◽  
Arvind Narayanaswamy
Keyword(s):  
Energy Transfer ◽  
Radiative Transfer ◽  
Near Field ◽  
Surface Polaritons ◽  
Field Effects ◽  
Polar Materials ◽  
Electro Magnetic ◽  
Collective Influence ◽  
Magnetic Waves

Near-field effects in radiative transfer refer to the collective influence of interference, diffraction, and tunneling of electro-magnetic waves on energy transfer between two or more objects. Most studies of near-field radiative transfer have so far focused on the enhancement due to tunneling of surface polaritons. In this work, we show the existence of sharp peaks in the radiative transfer spectrum between two spheres of polar materials that are not due to surface polaritons. The peaks, which are present on either side of the restrahlen band, are because of Mie resonances.

scholarly journals An Enhanced Multiplication of RF Energy Harvesting Efficiency Using Relay Resonator for Food Monitoring

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 1963 ◽  
Author(s):  
Xuan-Tu Cao ◽  
Wan-Young Chung
Keyword(s):  
Energy Harvesting ◽  
Power Transmission ◽  
Near Field ◽  
Magnetic Coupling ◽  
Electrical Energy ◽  
Transmission Efficiency ◽  
Smart Sensor ◽  
Rf Energy Harvesting ◽  
Sensor Module ◽  
Rf Energy

Recently, radio frequency (RF) energy harvesting (RFEH) has become a promising technology for a battery-less sensor module. The ambient RF radiation from the available sources is captured by receiver antennas and converted to electrical energy, which is used to supply smart sensor modules. In this paper, an enhanced method to improve the efficiency of the RFEH system using strongly coupled electromagnetic resonance technology was proposed. A relay resonator was added between the reader and tag antennas to improve the wireless power transmission efficiency to the sensor module. The design of the relay resonator was based on the resonant technique and near-field magnetic coupling concept to improve the communication distance and the power supply for a sensor module. It was designed such that the self-resonant frequencies of the reader antenna, tag antenna, and the relay resonator are synchronous at the HF frequency (13.56MHz). The proposed method was analyzed using Thevenin equivalent circuit, simulated and experimental validated to evaluate its performance. The experimental results showed that the proposed harvesting method is able to generate a great higher power up to 10 times than that provided by conventional harvesting methods without a relay resonator. Moreover, as an empirical feasibility test of the proposed RF energy harvesting device, a smart sensor module which is placed inside a meat box was developed. It was utilized to collect vital data, including temperature, relative humidity and gas concentration, to monitor the freshness of meat. Overall, by exploiting relay resonator, the proposed smart sensor tag could continuously monitor meat freshness without any batteries at the innovative maximum distance of approximately 50 cm.

Near-field radiative transfer in spectrally tunable double-layer phonon-polaritonic metamaterials

2018 ◽  
Vol 212 ◽  
pp. 120-127 ◽  
Author(s):  
Azadeh Didari ◽  
Elif Begüm Elçioğlu ◽  
Tuba Okutucu-Özyurt ◽  
M. Pinar Mengüç
Keyword(s):  
Radiative Transfer ◽  
Double Layer ◽  
Near Field

Near-Field Radiative Transfer, Dispersion Forces, and Dyadic Green’s Functions

2009 ◽  
Author(s):  
Arvind Narayanaswamy
Keyword(s):  
Radiative Transfer ◽  
Near Field ◽  
Field Enhancement ◽  
Zero Point ◽  
Thermal Fluctuations ◽  
Function Technique ◽  
Dispersion Forces ◽  
Maxwell Stress Tensor ◽  
Open Questions ◽  
Greens Function

Near–field force and energy exchange between two objects due to electrodynamic fluctuations give rise to dispersion forces such as Casimir and van der Waals forces, and thermal radiative transfer exceeding Plancks theory of blackbody radiation. The two phenomena dispersion forces and near–field enhancement of thermal radiation have common origins in the electromagnetic fluctuations. However, dispersion forces have contributions from quantum (zero–point) as well as thermal fluctuations whereas nearfield radiative transfer has contributions from thermal fluctuations alone. The forces are manifested through the Maxwell stress tensor of the electromagnetic field and radiative transfer through the Poynling vector. Both phenomena are elegantly described in terms of the Dyadic Greens function of the vector Helmholtz equation that governs the electromagnetic fields. In this talk, I will focus on the application of the Dyadic Greens function technique to near–field radiative transfer and dispersion forces. Despite the similarities, radiative transfer and forces have important differences that will be stressed on. I will end the talk with some open questions about the Dyadic Greens function formalism and its application to near–field radiative transfer.

scholarly journals Wide-angle, wide-band, polarization-insensitive metamaterial absorber for thermal energy harvesting

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ahmed Elsharabasy ◽  
Mohamed Bakr ◽  
M. Jamal Deen
Keyword(s):  
Optimal Design ◽  
Energy Harvesting ◽  
Thermal Energy ◽  
Near Field ◽  
Wide Band ◽  
Design Parameters ◽  
Perfect Absorber ◽  
Split Ring ◽  
Ir Radiation ◽  
Thermal Energy Harvesting

Abstract We propose a wide-band metamaterial perfect absorber (MPA), using the coupling in the near-field of a quadruple split-ring resonator concentric with crossed ellipses. We designed the MPA with a metal–insulator-metal (MIM) structure for use in thermal energy harvesting. A gradient-based optimization approach was carried out to maximize the absorption of infrared (IR) radiation around 10 μm. Owing to the near-field coupling of resonators with optimal design parameters, the peaks of the absorption responses approach each other, thus broadening the overall bandwidth with almost unity absorptivity. The proposed design has a resonance at 10 μm resulting from magnetic polaritons (MPs) and thus maintains high absorption above 99% up to a range of incident-angles greater than 60° and exhibits a polarization-free behavior due to symmetry. When the optimal design was numerically examined to fabrication tolerances, it showed negligible sensitivities in the absorptivity with respect to design parameters. The strong electric field enhancement inside the split-ring gaps and between the ends of the cross arms and the surrounding ring enables designing MIM diodes to rectify the harvested thermal radiations at 288 K. MIM diodes can be built by the deposition of thin insulators to sit in these gaps. The MIM diode and MPA work together to harvest and rectify the incident IR radiation in a manner similar to the operation of rectennas. The MPA outperforms the traditional nano-antennas in impedance matching efficiency because of its higher resistance. Also, its dual-polarization reception capability doubles the rectenna efficiency. Our proposed MPA retained absorptivity more than 99% when coupled with MIM diodes whose resistances are in the range of 500 Ω–1 MΩ.

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