scholarly journals Microfluidic Optical Shutter Flexibly x-y Actuated via Electrowetting-on-Dielectrics with <20 ms Response Time

2017 ◽  
Vol 2017 ◽  
pp. 1-5
Author(s):  
Henning Fouckhardt ◽  
Johannes Strassner ◽  
Carina Heisel ◽  
Dominic Palm ◽  
Christoph Doering
Keyword(s):  
Optical Properties ◽  
Response Time ◽  
Visible Spectral Range ◽  
Contact Structures ◽  
Light Path ◽  
Cell Type ◽  
Electrically Conductive ◽  
Droplet Movement ◽  
In Series ◽  
Optical Shutter

Tunable microoptics deals with devices of which the optical properties can be changed during operation without mechanically moving solid parts. Often a droplet is actuated instead, and thus tunable microoptics is closely related to microfluidics. One such device/module/cell type is an optical shutter, which is moved in or out of the path of the light. In our case the transmitting part comprises a moving transparent and electrically conductive water droplet, embedded in a nonconductive blackened oil, that is, an opaque emulsion with attenuation of 30 dB at 570 nm wavelength over the 250 μm long light path inside the fluid (15 dB averaged over the visible spectral range). The insertion loss of the cell is 1.5 dB in the “open shutter” state. The actuation is achieved via electrowetting-on-dielectrics (EWOD) with rectangular AC voltage pulses of 2·90 V peak-to-peak at 1 kHz. To flexibly allow for horizontal, vertical, and diagonal droplet movement in the upright x-y plane, the contact structures are prepared such that four possible stationary droplet positions exist. The cell is configured as two capacitors in series (along the z axis), such that EWOD forces act symmetrically in the front and back of the 60 nl droplet with a response time of <20 ms.

scholarly journals Nanostructured germanium deposited on heated substrates with enhanced photoelectric properties

2016 ◽  
Vol 7 ◽  
pp. 1492-1500 ◽  
Author(s):  
Ionel Stavarache ◽  
Valentin Adrian Maraloiu ◽  
Petronela Prepelita ◽  
Gheorghe Iordache
Keyword(s):  
Optical Properties ◽  
Response Time ◽  
Spectral Width ◽  
Fast Response ◽  
Superior Performance ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
Preparation Conditions ◽  
Photoelectric Properties ◽  
Transmission Electron

Obtaining high-quality materials, based on nanocrystals, at low temperatures is one of the current challenges for opening new paths in improving and developing functional devices in nanoscale electronics and optoelectronics. Here we report a detailed investigation of the optimization of parameters for the in situ synthesis of thin films with high Ge content (50 %) into SiO2. Crystalline Ge nanoparticles were directly formed during co-deposition of SiO2 and Ge on substrates at 300, 400 and 500 °C. Using this approach, effects related to Ge–Ge spacing are emphasized through a significant improvement of the spatial distribution of the Ge nanoparticles and by avoiding multi-step fabrication processes or Ge loss. The influence of the preparation conditions on structural, electrical and optical properties of the fabricated nanostructures was studied by X-ray diffraction, transmission electron microscopy, electrical measurements in dark or under illumination and response time investigations. Finally, we demonstrate the feasibility of the procedure by the means of an Al/n-Si/Ge:SiO2/ITO photodetector test structure. The structures, investigated at room temperature, show superior performance, high photoresponse gain, high responsivity (about 7 AW−1), fast response time (0.5 µs at 4 kHz) and great optoelectronic conversion efficiency of 900% in a wide operation bandwidth, from 450 to 1300 nm. The obtained photoresponse gain and the spectral width are attributed mainly to the high Ge content packed into a SiO2 matrix showing the direct connection between synthesis and optical properties of the tested nanostructures. Our deposition approach put in evidence the great potential of Ge nanoparticles embedded in a SiO2 matrix for hybrid integration, as they may be employed in structures and devices individually or with other materials, hence the possibility of fabricating various heterojunctions on Si, glass or flexible substrates for future development of Si-based integrated optoelectronics.

scholarly journals Proposal and Performance Evaluation of a Magneto-Striction Type Torque Sensor Consisting of Small-Sized Coils Connected in Series

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Takahiko Tsujisawa ◽  
Kazuhiro Yamakawa
Keyword(s):  
Performance Evaluation ◽  
Response Time ◽  
Detection Method ◽  
Torque Sensor ◽  
Detection Range ◽  
Performance Targets ◽  
Sensor Drift ◽  
In Series ◽  
Target Performance ◽  
And Performance

We propose a sensor consisting of small-sized coils connected in series and a detection method for the sensor based on the iteration of the periodic time difference. The evaluation results are also presented and show the effectiveness of the proposed system. The target performance of the sensor is as follows: (i) a detection range from 0 to ±100 Nm, (ii) a hysteresis error of less than 1%, (iii) an angular-dependent noise of less than 2%, and (iv) a sensor drift of less than 2%. From the evaluation results, it is clear that these performance targets, as well as a sufficient response time, are realized.

scholarly journals Velocity Distribution Characteristics Of Sea Water In Conductiv Magnetohydrodynamic (MHD) Homopolar Ducts

2015 ◽  
Vol 21 (3) ◽  
pp. 679-687
Author(s):  
Vasile Dobref ◽  
Petrică Popov ◽  
Silvestru Grozeanu
Keyword(s):  
Sea Water ◽  
Flow Characteristics ◽  
Modern Technology ◽  
Optimum Shape ◽  
Channel Axis ◽  
Electrically Conductive ◽  
Marine Propulsion ◽  
In Series ◽  
Physical Phenomena ◽  
Experimental And Theoretical Studies

Abstract Shortcomings of conventional propeller propulsion can theoretically be removed by using a modern technology - unconventional hydroelectromagnetic propeller or magnetohydrodynamic (MHD thruster), that highlights an application of great interest about physical phenomena that occur in the interaction between electromagnetic fields and electrically conductive fluids. In application to marine propulsion, investigations of a variety of physical phenomena was carried out, including the flow characteristics in a MHD duct, thrust efficiency and optimum shape of the duct. This paper presents related interaction phenomena between a magnetic induction, created by a d.c. electromagnet and d.c. current, perpendicular to the field, imposed by a voltage difference between two electrodes in the conductive sea water. The fluid is forced to the direction perpendicular to the plane where magnetic and electric fluxes are intersecting, this force is called the Lorentz force. Experimental and theoretical studies were carried out on small magnetohydrodynamic model (DC homopolar model) having two channels arranged in series or parallel. Each time the speed distribution was followed over the channel axis and perpendicular to channel axis.

The Influence of 4,4’-bis[6-(acryloyloxy)-hexyloxy]biphenyl Contents on the Electro-Optical Properties of Polymer Stabilized Liquid Crystals

2013 ◽  
Vol 634-638 ◽  
pp. 2523-2526
Author(s):  
Hui Chang ◽  
Wen Juan Fan ◽  
Xiao Li Liu ◽  
Hong Ying Huo
Keyword(s):  
Optical Properties ◽  
Liquid Crystals ◽  
Response Time ◽  
Polymer Network ◽  
Contrast Ratio ◽  
Monomer Concentration ◽  
Helical Structure ◽  
Switching Process ◽  
Polymer Stabilized ◽  
Structure Of Liquid

The polymer stabilized liquid crystals (PSLC) films was prepared subsequently based on the mesogenic diacrylate monomer 4,4’-bis[6-(acryloyloxy)-hexyloxy]biphenyl (BAB6). The effects of BAB6 on the morphology of polymer network as well as the electro-optical properties of the PSLC films were investigated. The helical structure of liquid crystals was observed in the morphology of polymer network by SEM. Further, a single switching process was observed at lower monomer concentration in this study compared with the former publication. When BAB6 concentration reached 7 %, the response time and contrast ratio of PSLC film were 7 ms and 16.8, respectively.

scholarly journals Hg2+ Detection with Rational Design of DNA-Templated Fluorescent Silver Nanoclusters

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1699
Author(s):  
Liam Yourston ◽  
Polikron Dhoqina ◽  
Nolan Marshall ◽  
Rujani Mahmud ◽  
Ethen Kuether ◽  
...  
Keyword(s):  
Optical Properties ◽  
Rational Design ◽  
Visible Spectral Range ◽  
Silver Nanoclusters ◽  
Hairpin Loop ◽  
Fluorescent Properties ◽  
Dna Oligonucleotides ◽  
Loop Sequence ◽  
Detectable Range ◽  
Additional Stability

Atomically precise silver nanoclusters (AgNCs) are small nanostructures consisting of only a few atoms of silver. The combination of AgNCs with cytosine-rich single-stranded oligonucleotides results in DNA-templated silver nanoclusters (DNA-AgNCs). DNA-AgNCs are highly luminescent and can be engineered with reproducible and unique fluorescent properties. Furthermore, using nucleic acids as templates for the synthesis of AgNCs provides additional practical benefits by expanding optical activity beyond the visible spectral range and creating the possibility for color tunability. In this study, we explore DNA oligonucleotides designed to fold into hairpin-loop (HL) structures which modulate optical properties of AgNCs based on the size of the loop containing different number of cytosines (HL-CN). Depending on the size of the loop, AgNCs can be manufactured to have either single or multiple emissive states. Such hairpin-loop structures provide an additional stability for AgNCs and further control over the base composition of the loop, allowing for the rational design of AgNCs’ optical properties. We demonstrate the potential of AgNCs in detecting Hg2+ by utilizing the HL-C13 design and its variants HL-T2C11, HL-T4C9, and HL-T6C7. The replacement of cytosines with thymines in the loop was intended to serve as an additional sink for mercury ions extending the detectable range of Hg2+. While AgNC@HL-T0C13 exhibits an interpretable quenching curve, AgNC@HL-T6C7 provides the largest detectable range of Hg2+. The results presented herein suggest that it is possible to use a rational design of DNA-AgNCs based on the composition of loop sequence in HL structures for creating biosensors to detect heavy metals, particularly Hg2+.

scholarly journals In situ polymerization of PEDOT:PSS films based on EMI-TFSI and the analysis of electrochromic performance

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 722-733
Author(s):  
Haiyun Jiang ◽  
Wei Wu ◽  
Zigong Chang ◽  
Hailan Zeng ◽  
Ronglian Liang ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Optical Properties ◽  
Diffusion Coefficient ◽  
Response Time ◽  
Color Change ◽  
In Situ Polymerization ◽  
Electrochemical Polymerization ◽  
Composite Films ◽  
Ion Diffusion

Abstract In this report, PEDOT composite films were prepared by in situ electrochemical polymerization. 1-Ethyl-3-methylimidazole bis(trifluoromethylsulfonyl)imide (EMI-TFSI) was used as an ionic liquid dopant for PEDOT:PSS films. Subsequently, these PEDOT:PSS/EMI-TFSI films were compared with PEDOT:PSS films based on their morphology, structure, electrochromic properties, and optical properties at different deposition voltages and deposition times. It was observed that the addition of EMI-TFSI enhanced all the aforementioned properties of the films. PEDOT:PSS/EMI-TFSI films were seen to have a larger ion diffusion coefficient (1.38 × 10−20 cm2·s−1), a wider color change range (43.48%), a shorter response time (coloring response time = 1.2 s; fade response time = 2 s), and a higher coloring efficiency (189.86 cm2·C−1) when compared with normal PEDOT:PSS films. The introduction of EMI-TFSI in the films ultimately resulted in superior electrochemical and optical properties along with higher stability.

Hybrid MnO2/C nano-composites on a macroporous electrically conductive network for supercapacitor electrodes

2015 ◽  
Vol 3 (32) ◽  
pp. 16695-16707 ◽  
Author(s):  
Dajun Wu ◽  
Shaohui Xu ◽  
Mai Li ◽  
Chi Zhang ◽  
Yiping Zhu ◽  
...  
Keyword(s):  
Negative Electrode ◽  
Nano Composites ◽  
Conductive Network ◽  
Electrically Conductive ◽  
Blue Led ◽  
Hybrid Device ◽  
In Series

Hybrid MnO2/C nano-composites are formed on a macroporous electrically conductive network as a negative electrode. Three devices packaged in CR2032 batteries in series can power a blue LED for about 100 minutes after charging each hybrid device for 30 s.

INFRARED PHOTOREFRACTIVE COMPOSITES BASED ON POLYIMIDE AND J-AGGREGATES OF CYANINE DYE

2005 ◽  
Vol 14 (03) ◽  
pp. 439-447 ◽  
Author(s):  
A. V. VANNIKOV ◽  
A. D. GRISHINA ◽  
L. YA. PERESHIVKO ◽  
T. V. KRIVENKO ◽  
V. V. SAVELYEV ◽  
...  
Keyword(s):  
Optical Properties ◽  
Electric Field ◽  
Response Time ◽  
External Electric Field ◽  
Gain Coefficient ◽  
Cyanine Dye ◽  
Third Order ◽  
Aromatic Polyimide ◽  
Photoelectric Sensitivity ◽  
J Aggregates

Photorefractive composites sensitive to 1064 nm on a base of an aromatic polyimide containing J-aggregates of a thiacarbocyanine dye are presented. The molecules of the dye form the nanocrystalline J-aggregates that are responsible for photoelectric sensitivity at 1064 nm and nonlinear third-order optical properties. The net gain coefficient 266 cm-1 and the response time 0.09 s were achieved at an external electric field of about 15 V/μm.

scholarly journals Heterogeneous OH oxidation of secondary brown carbon aerosol

2018 ◽  
Author(s):  
Elijah G. Schnitzler ◽  
Jonathan P. D. Abbatt
Keyword(s):  
Optical Properties ◽  
Single Scattering ◽  
Trace Gas ◽  
Absorption Enhancement ◽  
Brown Carbon ◽  
Scattering Coefficients ◽  
Aerosol Absorption ◽  
In Series ◽  
First Time ◽  
Slow Absorption

Abstract. Light-absorbing organic aerosol, or brown carbon (BrC), has significant but poorly-constrained effects on climate; for example, oxidation in the atmosphere may alter its optical properties, leading to absorption enhancement or bleaching. Here, we investigate for the first time the effects of heterogeneous OH oxidation on the optical properties of a laboratory surrogate of secondary BrC in a series of photo-oxidation chamber experiments. The BrC surrogate was generated from aqueous resorcinol, or 1,3-dihydroxybenzene, and H2O2 exposed to > 300 nm radiation, atomized, passed through trace gas denuders, and injected into the chamber, which was conditioned to either 15 or 60 % relative humidity (RH). Aerosol absorption and scattering coefficients and single scattering albedo (SSA) at 405 nm were measured using a photo-acoustic spectrometer. At 60 % RH, upon OH exposure, absorption first increased, and the SSA decreased sharply. Subsequently, absorption decreased faster than scattering, and SSA increased gradually. Comparisons to the modelled trend in SSA, based on Mie theory calculations, confirm that the observed trend is due to chemical evolution, rather than slight changes in particle size. The initial absorption enhancement is likely due to molecular functionalization and/or oligomerization, and the bleaching to fragmentation. By contrast, at 15 % RH, slow absorption enhancement was observed, without appreciable bleaching. A multi-layer kinetics model, consisting of two surface reactions in series, was constructed to provide further insights regarding the RH-dependence of the optical evolution. Candidate parameters suggest that the oxidation is efficient, with uptake coefficients on the order of unity, and the aerosol is very viscous, even at 60 % RH. At 15 % RH, the aerosol will be viscous enough to confine products of fragmentation, leading to their recombination, such that little bleaching is observed on the experimental timescale. These results further the current understanding of the complex processing of BrC that may occur in the atmosphere.

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