There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

https://www.uta.edu/rfmems/GI_Sensor/papers/ac040049d.pdf

Fiber-Optic Chemical Sensors and Biosensors

Today cross-cutting approaches, where molecular engineering and clever processing are synergistically coupled, allow the chemist to tailor complex hybrid systems of various shapes with perfect mastery at different size scales, composition, functionality, and morphology. Hybrid materials with organic–inorganic or bio–inorganic character represent not only a new field of basic research but also, via their remarkable new properties and multifunctional nature, hybrids offer prospects for many new applications in extremely diverse fields. The description and discussion of the major applications of hybrid inorganic–organic (or biologic) materials are the major topic of this critical review. Indeed, today the very large set of accessible hybrid materials span a wide spectrum of properties which yield the emergence of innovative industrial applications in various domains such as optics, micro-electronics, transportation, health, energy, housing, and the environment among others (526 references).

Applications of advanced hybrid organic–inorganic nanomaterials: from laboratory to market

An increase in world population along with a significant aging portion is forcing rapid rises in healthcare costs. The healthcare system is going through a transformation in which continuous monitoring of inhabitants is possible even without hospitalization. The advancement of sensing technologies, embedded systems, wireless communication technologies, nano technologies, and miniaturization makes it possible to develop smart systems to monitor activities of human beings continuously. Wearable sensors detect abnormal and/or unforeseen situations by monitoring physiological parameters along with other symptoms. Therefore, necessary help can be provided in times of dire need. This paper reviews the latest reported systems on activity monitoring of humans based on wearable sensors and issues to be addressed to tackle the challenges.

Wearable Sensors for Human Activity Monitoring: A Review

By coating a single-mode-multimode-single-mode (SMS) structure with a complex refractive index thin-film the central wavelength of the transmission and attenuation bands of the optical spectrum can be shifted. By adequate selection of multimode segment length and diameter, the thin-film thickness and the thin-film refractive index, the sensitivity of the device to the surrounding medium refractive index, the thickness of the thin-film or the refractive index of the thin-film can be optimized. Experimental results are corroborated numerically with the transfer matrix method.

/pdf/optimization-of-sensors-based-on-multimode-interference-in-4z7mzqlnt2.pdf

Optimization of Sensors Based on Multimode Interference in Single-Mode–Multimode–Single-Mode Structure

Optical fiber gas sensors have been fabricated by deposition of Al/sub 2/O/sub 3/ and polymer ultra-thin films on the ends of optical fibers using the electrostatic self assembly monolayer process These sensors are designed to operate at the standard transmission wavelengths with no cross sensitivity to temperature from at least 10 to 70/spl deg/C Experimental results of the response of these sensors to organic volatile compounds such as acetone, dichloromethane, or ethanol, are presented In addition, a thermal curing process is proposed for achieving a humidity cross sensitivity of less than 14% from 11% to 85% of relative humidity, this cross sensitivity was still negligible after one year of the thermal curing process

Optical fiber gas sensors based on hydrophobic alumina thin films formed by the electrostatic self-assembly monolayer process

In this work an optical fiber tunable filter based on lossy guided-mode resonances (LGMR) is proposed. It consists of a multilayer structure deposited onto the surface of a plastic cladding removed multimode fiber. The first layer is used to generate the LGMR and to work as the first electrode as well; the second one to tune the filter and the outer layer forms the other electrode. The fabricated filter has demonstrated a good sensitivity to the applied voltage showing a change of the LGMR wavelength of 0.4 nm/V. Among other applications, this filter is intended to be used as electro-optic wavelength filter or modulator.

Tunable electro-optic wavelength filter based on lossy-guided mode resonances

A novel and high sensitive IgG – anti-IgG biosensor based on multimode interference induced through a single-mode–multimode–single-mode (SMS) optical fiber structure is developed in this contribution. First, an improvement of the performance of a basic 125-μm-diameter SMS structure is carried out by etching the optical waveguide cladding to a diameter of 15 μm. This leads to sensitivity values eight times higher than the original SMS structure. Then, 3-glycidopropyl-trimethoxysilane is used to attach the IgGs to the optical substrate. Finally, a phosphate buffer saline solution containing an increasing concentration of antigoat IgGs is used to detect biological interactions up to 104 μg/ml. High-resolution mass spectrometry was used to corroborate the attachment of the biomolecules to the optic fiber. The analyzed bioprobe presents no cross sensitivity to other biomolecules immersed in the same detection solution.

Fiber-Optic Immunosensor Based on an Etched SMS Structure

In this work, lossy mode resonance (LMR)-based optical fiber refractometers fabricated by using a transparent coating (indium oxide) as the LMR supporting layer are studied. The utilization of the high refractive index indium oxide coatings enables the fabrication of highly sensitive optical fiber refractometers, the resonance of which can be tuned by adjusting the fabrication parameters, such as the coating thickness. The detection technique is based on the wavelength shift of the resonances produced by both TE and TM polarization modes. Here, the influence of the coating thickness on the sensitivity of the device to external refractive index variations is observed. Maximum sensitivities of 2.03e-4 and 2.35e-4 refractive index units (RIU) per nanometer for TE and TM polarizations have been obtained, respectively. The sensitivity of the devices to diverse volatile organic compounds (VOCs), such as ethanol, methanol, isopropyl alcohol, acetone, and ammonia has been studied and the cross-sensitivity to temperature and moisture as well.

Ignacio R. Matias

Papers

Optimization of Sensors Based on Multimode Interference in Single-Mode–Multimode–Single-Mode Structure

Optical fiber gas sensors based on hydrophobic alumina thin films formed by the electrostatic self-assembly monolayer process

Tunable electro-optic wavelength filter based on lossy-guided mode resonances

Fiber-Optic Immunosensor Based on an Etched SMS Structure

Sensing Properties of Indium Oxide Coated Optical Fiber Devices Based on Lossy Mode Resonances