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

[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Since the first application of the surface plasmon resonance (SPR) phenomenon for sensing almost two decades ago, this method has made great strides both in terms of instrumentation development and applications. SPR sensor technology has been commercialized and SPR biosensors have become a central tool for characterizing and quantifying biomolecular interactions. This paper attempts to review the major developments in SPR technology. Main application areas are outlined and examples of applications of SPR sensor technology are presented. Future prospects of SPR sensor technology are discussed.

Surface plasmon resonance sensors: review

http://www.nanoscience.gatech.edu/paper/2012/12_NE_04.pdf

Flexible triboelectric generator

Lanthanide-based luminescent hybrid materials.

Energy harvesting generators are attractive as inexhaustible replacements for batteries in low-power wireless electronic devices and have received increasing research interest in recent years. Ambient motion is one of the main sources of energy for harvesting, and a wide range of motion-powered energy harvesters have been proposed or demonstrated, particularly at the microscale. This paper reviews the principles and state-of-art in motion-driven miniature energy harvesters and discusses trends, suitable applications, and possible future developments.

/pdf/energy-harvesting-from-human-and-machine-motion-for-wireless-3lsf4oudvo.pdf

Energy Harvesting From Human and Machine Motion for Wireless Electronic Devices

Several forms of vibration-driven MEMS microgenerator are possible and are reported in the literature, with potential application areas including distributed sensing and ubiquitous computing. This paper sets out an analytical basis for their design and comparison, verified against full time-domain simulations. Most reported microgenerators are classified as either velocity-damped resonant generators (VDRGs) or Coulomb-damped resonant generators (CDRGs) and a unified analytical structure is provided for these generator types. Reported generators are shown to have operated at well below achievable power densities and design guides are given for optimising future devices. The paper also describes a new class-the Coulomb-force parametric generator (CFPG)-which does not operate in a resonant manner. For all three generators, expressions and graphs are provided showing the dependence of output power on key operating parameters. The optimization also considers physical generator constraints such as voltage limitation or maximum or minimum damping ratios. The sensitivity of each generator architecture to the source vibration frequency is analyzed and this shows that the CFPG can be better suited than the resonant generators to applications where the source frequency is likely to vary. It is demonstrated that mechanical resonance is particularly useful when the vibration source amplitude is small compared to the allowable mass-to-frame displacement. The CDRG and the VDRG generate the same power at resonance but give better performance below and above resonance respectively. Both resonant generator types are unable to operate when the allowable mass frame displacement is small compared to the vibration source amplitude, as is likely to be the case in some MEMS applications. The CFPG is, therefore, required for such applications.

https://spiral.imperial.ac.uk:8443/bitstream/10044/1/997/1/Architectures%20for%20vibration-driven.pdf

Architectures for vibration-driven micropower generators

This paper describes the analysis, simulation and testing of a microengineered motion-driven power generator, suitable for application in sensors within or worn on the human body. Micro-generators capable of powering sensors have previously been reported, but these have required high frequency mechanical vibrations to excite a resonant structure. However, body-driven movements are slow and irregular, with large displacements, and hence do not effectively couple energy into such generators. The device presented here uses an alternative, non-resonant operating mode. Analysis of this generator shows its potential for the application considered, and shows the possibility to optimise the design for particular conditions. An experimental prototype based on a variable parallel-plate capacitor operating in constant charge mode is described which confirms the analysis and simulation models. This prototype, when precharged to 30 V, develops an output voltage of 250 V, corresponding to 0.3J per cycle. The experimental test procedure and the instrumentation are also described.

/pdf/mems-electrostatic-micropower-generator-for-low-frequency-pcywa0q5az.pdf

MEMS electrostatic micropower generator for low frequency operation

Because of the low dimensional power of its force scaling law, surface tension is appropriate for carrying out reshaping and assembly in the microstructure size domain. This paper reviews work on surface tension powered self-assembly of microstructures. The existing theoretical approaches for rotational assembly are unified. The demonstrated fabrication processes are compared. Mechanisms for accurately determining the assembled shape are discussed, and the limits on accuracy and structural distortion are considered. Applications in optics, electronics and mechanics are described. More complex operations (including the combination of self-assembly and self-organization) are also reviewed.

Surface tension-powered self-assembly of microstructures - the state-of-the-art

Energy harvesting from human motion faces the challenges of low frequency and random excitation. One strategy that has been successful in the past is frequency up-conversion. This paper introduces an inertial device that combines this principle, in the form of piezoelectric beam plucking through magnetic coupling with a rotating proof mass. The advantages rotational systems can have for body movements are discussed. The prototype is described and tested in a real world environment during a running race and later on in a laboratory environment on a custom built linear excitation table. Throughout these tests it is confirmed that such a device can operate over a broad range of frequencies and under varying orientations, making it suitable for this intended application. Across frequencies between 0.5 and 4 Hz and accelerations between 1 and 20 m/s2 power outputs in the range of tens of microwatts were achieved, with a peak value of 43 μW at 2 Hz and 20 m/s2 when the rotor went into a continuous rotation.

Eric M. Yeatman

Papers

Energy Harvesting From Human and Machine Motion for Wireless Electronic Devices

Architectures for vibration-driven micropower generators

MEMS electrostatic micropower generator for low frequency operation

Surface tension-powered self-assembly of microstructures - the state-of-the-art

A piezoelectric frequency up-converting energy harvester with rotating proof mass for human body applications