Mechanical Motion of Chiral Azobenzene Crystals with Twisting upon Photoirradiation

2016 ◽  
Vol 22 (23) ◽  
pp. 7950-7958 ◽  
Author(s):  
Takuya Taniguchi ◽  
Juri Fujisawa ◽  
Motoo Shiro ◽  
Hideko Koshima ◽  
Toru Asahi
Keyword(s):  
Mechanical Motion

scholarly journals Microwave oscillator and frequency comb in a silicon optomechanical cavity with a full phononic bandgap

Nanophotonics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 3535-3544 ◽  
Author(s):  
Laura Mercadé ◽  
Leopoldo L. Martín ◽  
Amadeu Griol ◽  
Daniel Navarro-Urrios ◽  
Alejandro Martínez
Keyword(s):  
Phase Noise ◽  
Frequency Comb ◽  
Microwave Oscillator ◽  
New Paradigm ◽  
Mechanical Motion ◽  
Optical Fields ◽  
Optical Resonance ◽  
Processing Elements ◽  
Low Weight ◽  
Harmonic Mixing

AbstractCavity optomechanics has recently emerged as a new paradigm enabling the manipulation of mechanical motion via optical fields tightly confined in deformable cavities. When driving an optomechanical (OM) crystal cavity with a laser blue-detuned with respect to the optical resonance, the mechanical motion is amplified, ultimately resulting in phonon lasing at MHz and even GHz frequencies. In this work, we show that a silicon OM crystal cavity performs as an OM microwave oscillator when pumped above the threshold for self-sustained OM oscillations. To this end, we use an OM cavity designed to have a breathing-like mechanical mode at 3.897 GHz in a full phononic bandgap. Our measurements show that the first harmonic of the detected signal displays a phase noise of ≈−100 dBc/Hz at 100 kHz. Stronger blue-detuned driving leads eventually to the formation of an OM frequency comb, whose lines are spaced by the mechanical frequency. We also measure the phase noise for higher-order harmonics and show that, unlike in Brillouin oscillators, the noise is increased as corresponding to classical harmonic mixing. Finally, we present real-time measurements of the comb waveform and show that it can be fitted to a theoretical model recently presented. Our results suggest that silicon OM cavities could be relevant processing elements in microwave photonics and optical RF processing, in particular in disciplines requiring low weight, compactness and fiber interconnection.

scholarly journals Mechanically Strong, Liquid-Resistant Photothermal Bioplastic Constructed from Cellulose and Metal-Organic Framework for Light-Driven Mechanical Motion

Molecules ◽  
2021 ◽  
Vol 26 (15) ◽  
pp. 4449
Author(s):  
Lijian Sun ◽  
Limei Li ◽  
Xianhui An ◽  
Xueren Qian
Keyword(s):  
Prussian Blue ◽  
Thermoelectric Generator ◽  
Metal Organic Framework ◽  
In Situ Synthesis ◽  
High Light ◽  
Hot Press ◽  
Mechanical Motion ◽  
Metal Organic ◽  
Organic Framework

The development of photothermal materials with a high light-to-heat conversion capability is essential for the utilization of clean solar energy. In this work, we demonstrate the use of a novel and sustainable concept involving cellulose liquefaction, rapid gelation, in situ synthesis and hot-press drying to convert cellulose and metal–organic framework (Prussian blue) into a stable photothermal bioplastic that can harvest sunlight and convert it into mechanical motion. As expected, the obtained Prussian blue@cellulose bioplastic (PCBP) can effectively absorb sunlight and the surface can be heated up to 70.3 °C under one sun irradiation (100 mW cm−2). As a demonstration of the practicality of PCBP, it was successfully used to drive a Stirling engine motion. Meanwhile, hot-pressing promotes the densification of the structure of PCBP and, therefore, improves the resistance to the penetration of water/non-aqueous liquids. Moreover, PCBP shows good mechanical properties and thermal stability. Given the excellent photothermal performance and environmentally friendly features of photothermal conversion bioplastic, we envisage this sustainable plastic film could play important roles toward diversified applications: a photothermal layer for thermoelectric generator, agricultural films for soil mulching and photothermal antibacterial activity, among others.

scholarly journals Monitoring mechanical motion of carbon nanotube based nanomotor by optical absorption spectrum

2016 ◽  
Vol 109 (26) ◽  
pp. 263104 ◽  
Author(s):  
Baomin Wang ◽  
Xuewei Cao ◽  
Zhan Wang ◽  
Yong Wang ◽  
Kaihui Liu
Keyword(s):  
Absorption Spectrum ◽  
Carbon Nanotube ◽  
Optical Absorption ◽  
Optical Absorption Spectrum ◽  
Mechanical Motion

scholarly journals Simulation of the dynamic behaviour of a permanent magnet linear actuator

2010 ◽  
Vol 23 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Ivan Yatchev ◽  
Vultchan Gueorgiev ◽  
Racho Ivanov ◽  
Krastio Hinov
Keyword(s):  
Permanent Magnet ◽  
Dynamic Behaviour ◽  
Electric Circuit ◽  
Linear Actuator ◽  
Soft Magnetic ◽  
Mechanical Motion ◽  
Field Problem ◽  
Motion Problems ◽  
Long Stroke ◽  
The Magnetic Field

The paper presents simulation of the dynamics of a permanent magnet linear actuator with soft magnetic mover and relatively long stroke 60 mm. The simulation is carried out using decoupled approach where the magnetic field problem is solved separately from the electric circuit and mechanical motion problems. The obtained results are compared with experiment. .

Energy Harvesting From Pneumatic Tires Using Piezoelectric Transducers

2008 ◽  
Author(s):  
Farbod Khameneifar ◽  
Siamak Arzanpour
Keyword(s):  
Energy Harvesting ◽  
Lead Zirconate Titanate ◽  
Ground Surface ◽  
Lead Zirconate ◽  
Electrical Circuit ◽  
Piezoelectric Transducers ◽  
Vehicle Speed ◽  
Mechanical Motion ◽  
The Road ◽  
Optimum Load

The concept of harvesting energy in our surrounding has recently drawn global attention. Harvesting the ambient energy of the deflected tire and convert it to electricity is discussed in this paper. An Elastic pneumatic tire deflects due to the load it carries. This deflection appears as a contact patch to the road surface. Initially, the concept of the tire deflection will be discussed. This deflection is then related to the wasted energy used for deflection. The dependency of this energy to some important parameters such as the tire air pressure, vehicle speed and tire geometry and forces are primarily discussed. To harvest the deflection energy different well established methods are exists. Due to the tire environment, piezoelectric transducers can serve as the best option. Those transducers are traditionally used to produce mechanical motion due to the applied electrical charges. This material is also capable of generating electrical charges by mechanical motion and deflections. For the tire energy harvesting application, the piezoelectric stacks can be mounted inside a tire structure such that electric charge is generated therein as the wheel assembly moves along a ground surface. For this application, lead-zirconate-titanate (PZT) is selected. The PZT inside the tire is modeled as a cantilever beam vibration in its first mode of vibration. The frequency of vibration is calculated based on the car speed, tire size, and PZT stack length. A mathematical model for this energy harvesting application is derived. Based on this model, the optimum load of the electrical circuit is also found. Finally the amount of energy harvested from tire using PZT is calculated. Although this energy is not significantly high, it will be enough to provide power for wireless sensors applications.

Effect of Motion on the Sonographic and Magnetic Resonance Patterns of Ageing Blood

1986 ◽  
Vol 27 (4) ◽  
pp. 455-458 ◽  
Author(s):  
A. Alanen ◽  
P. Nummi
Keyword(s):  
Magnetic Resonance ◽  
Relaxation Times ◽  
Large Change ◽  
Proton Relaxation ◽  
Mechanical Motion ◽  
Microscopic Appearance ◽  
Histologic Appearance ◽  
Blood Clots ◽  
T1 And T2

The sonographic appearance of a hematoma may be affected by various factors, including the age of the hematoma. The effect of mechanical motion on the echogenicity and histologic appearance, and on the proton relaxation times T1 and T2 of blood clots, was studied in vitro for up to 21 days. All clots were of similar echogenicity and microscopic appearance during the first 2 days. The minimally disturbed clots were sonolucent from day 4 onwards, whereas moderate mechanical disturbance changed the microscopic structure of the blood clots and caused them to retain their echogenicity. Proton relaxation times T1 and T2 of both minimally disturbed and vigorously manipulated blood samples showed a rapid shortening of T1 and a less marked decrease of T2 between days 1 and 4, which was independent of mechanical motion. The ultrasonic appearance reflected the histologic appearance but not necessarily the age of the clot. The magnetic resonance (MR) parameters T1 and to a lesser extent T2 accurately reflected the age of the clot during the first 6 days. Although relatively gentle motion caused a large change in the ultrasonic appearance of the clots, vigorous shaking did not affect the magnetic resonance appearance of human blood clots.

Quadratic Time Increment Indexing for Stepper Motor Motion Control

1987 ◽  
Author(s):  
M. Savage ◽  
J. E. Grover
Keyword(s):  
Motion Control ◽  
Fundamental Problem ◽  
Real Time Control ◽  
Mechanical Motion ◽  
Specific System ◽  
Maximum Torque ◽  
Time Increment ◽  
Time Control ◽  
Indexing System ◽  
Pulse Timing

Abstract A fundamental problem of mechanical motion control is that of indexing a mass reliably from one stationary position to another in a given time with as little power as possible. A quadratic time increment function is proposed and demonstrated for stepping motor control. With this function, a given motor can index a mass through a variety of index lengths. The indexing system includes a microprocessor to adjust the motor pulse timing to index the inertial load through a range of motions — each with the same maximum torque. The functions and the sizing of the motor are described. The interaction between the microprocessor calculation speed and the indexing capability is given for achievable real time control. Experimental results for a specific system are presented.

scholarly journals Vital Sign Monitoring in Car Seats Based on Electrocardiography, Ballistocardiography and Seismocardiography: A Review

Sensors ◽  
2020 ◽  
Vol 20 (19) ◽  
pp. 5699
Author(s):  
Michaela Sidikova ◽  
Radek Martinek ◽  
Aleksandra Kawala-Sterniuk ◽  
Martina Ladrova ◽  
Rene Jaros ◽  
...  
Keyword(s):  
Signal Processing ◽  
Motion Analysis ◽  
Vital Sign ◽  
Potential Application ◽  
Steering Wheel ◽  
Vital Function ◽  
Mechanical Motion ◽  
Comprehensive Overview ◽  
Car Seats ◽  
Signal Processing Methods

This paper focuses on a thorough summary of vital function measuring methods in vehicles. The focus of this paper is to summarize and compare already existing methods integrated into car seats with the implementation of inter alia capacitive electrocardiogram (cECG), mechanical motion analysis Ballistocardiography (BCG) and Seismocardiography (SCG). In addition, a comprehensive overview of other methods of vital sign monitoring, such as camera-based systems or steering wheel sensors, is also presented in this article. Furthermore, this work contains a very thorough background study on advanced signal processing methods and their potential application for the purpose of vital sign monitoring in cars, which is prone to various disturbances and artifacts occurrence that have to be eliminated.

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