- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Photo-responsible Synapse using Ge Synaptic Transistors and GaAs Photodetectors
摘要： Current neural networks are accumulating accolades for their performance on a variety of real-world computational tasks including recognition, classification, regression, and prediction, yet there are few scalable architectures that have emerged to address the challenges posed by their computation. This paper introduces Minitaur, an event-driven neural network accelerator, which is designed for low power and high performance. As an field-programmable gate array-based system, it can be integrated into existing robotics or it can offload computationally expensive neural network tasks from the CPU. The version presented here implements a spiking deep network which achieves 19 million postsynaptic currents per second on 1.5 W of power and supports up to 65 K neurons per board. The system records 92% accuracy on the MNIST handwritten digit classification and 71% accuracy on the 20 newsgroups classification data set. Due to its event-driven nature, it allows for trading off between accuracy and latency.
关键词： Deep belief networks,spiking neural networks,field programmable arrays,restricted Boltzmann machines,neural networks,machine learning
更新于2025-09-23 15:19:57
-
Fabrication and Characterization of Ni-Doped ZnO Nanorod Arrays for UV Photodetector Application
摘要： In this work, the structure morphologies, lattices, and optical properties of zinc oxide (ZnO) nanorods (NRs) with various amounts of nickel (Ni) dopants were investigated and explored. The 100 nm ZnO seed layer was grown on the Corning glass substrate by the radio frequency (RF) magnetron sputtering technique, and the chemical bath deposition (CBD) method was used to grow NR arrays. It was found that the Ni concentration of the sample is 1.06 at% by EDX spectra examination. All the NRs exhibited a hexagonal wurtzite structure and preferentially grew along the c-axis on the substrate. Additionally, the ultraviolet (UV) photodetectors (PDs) with Ni-doped ZnO (NZO) NRs based on metal-semiconductor-metal (MSM) structure were fabricated through a photolithography process. Then, such a sample was annealed at 500 °C to obtain good performance and reduced oxygen vacancy (～560 nm). The results showed that the NZO NRs were with an excellent photosensitivity for UV PD applications and a faster rise/decay time than pure ZnO. Furthermore, with a 3 V applied bias and 380 nm UV illumination, the sensitivities of the fabricated ZnO PDs with different Ni contents (0, 4, and 8 mM) were 71.45, 393.04, and 238.75, respectively.
关键词： nanorod arrays,photolithography process,chemical bath deposition,UV photodetector,Ni-doped ZnO
更新于2025-09-23 15:19:57
-
Improvement in light out-coupling efficiency of OLED by using high fill factor parabola curve microlens arrays
摘要： Aspheric microlens arrays (MLAs) are introduced on glass substrate to improve the light out-coupling efficiency (LOCE) of organic light-emitting diode (OLED). Geometric ray tracing was employed to simulate the improved effects and optimize the structure parameters of the MLAs pattern. The simulation results show that when the parameters of MLAs as follows, the curved profile is parabola, the base shape is hexagon, the fill factor is 1, the aspect ratio is 0.6, and the material refractive index should be match to that of the substrate of the OLED, which can improve LOCE maximum. Poly-dimethyl-siloxane (PDMS) parabola curve MLAs films ware fabricated by maskless lithography technique and template replication. The experimental results show that the MLAs can improve the LOCE and the trends of the experimental results agree with the simulation results. A maximum increase of 49% in the coupling efficiency was achieved.
关键词： light out-coupling efficiency,aspheric microlens arrays,OLED,parabola curve
更新于2025-09-23 15:19:57
-
Actuated plasmonic nanohole arrays for sensing and optical spectroscopy applications
摘要： Herein, we report a new approach to rapidly actuate the plasmonic characteristics of thin gold films perforated with nanohole arrays that are coupled with arrays of gold nanoparticles. The near-field interaction between the localized and propagating surface plasmon modes supported by the structure was actively modulated by changing the distance between the nanoholes and nanoparticles and varying the refractive index symmetry of the structure. This approach was applied by using a thin responsive hydrogel cushion, which swelled and collapsed by a temperature stimulus. The detailed experimental study of the changes and interplay of localized and propagating surface plasmons was complemented by numerical simulations. We demonstrate that the interrogation and excitation of the optical resonance to these modes allow the label-free SPR observation of the binding of biomolecules, and is applicable for in situ SERS studies of low molecular weight molecules attached in the gap between the nanoholes and nanoparticles.
关键词： gold nanoparticles,responsive hydrogel,plasmonic nanohole arrays,surface plasmon resonance,SERS
更新于2025-09-23 15:19:57
-
A 38 dBi Gain, Low-Loss, Flat Array Antenna for 320 GHz to 400 GHz Enabled by Silicon-On-Insulator Micromachining
摘要： Two high-gain ?at array antenna designs operating in the 320 – 400 GHz frequency range are reported in this paper. The two antennas show measured gains of 32.8 dBi and 38 dBi and consist of a 16 × 16 (256) element array and a 32 × 32 (1024) element array, respectively, which are fed by a corporate H-tree beamforming network. The measured operation bandwidth for both antennas is 80 GHz (22 % fractional bandwidth), and the total measured ef?ciency is above ?2.5 dB and above ?3.5 dB for the two designs in the whole bandwidth. The low measured loss and large bandwidth are enabled by optimizing the designs to the process requirements of the SOI micromachining technology used in this work. The total height of the antennas is 1.1 mm (1.2 λ at the center frequency), with sizes of 15 mm × 18 mm and 27 mm × 30 mm for both arrays. The antennas are designed to be directly mounted onto a standard WM-570 waveguide ?ange. The design, fabrication, and measurements of eight prototypes are discussed in this paper and the performance of the antennas compared to the simulated data, as well as manufacturability and fabrication repeatability are reported in detail.
关键词： terahertz radiation,corporate beamforming network,array antennas,silicon micromachining,silicon on insulator,waveguide arrays,submillimeter-wave antennas
更新于2025-09-23 15:19:57
-
Controlled Phase Gate Protocol for Neutral Atoms via Off-Resonant Modulated Driving
摘要： Neutral-atom arrays serve as an ideal platform to study quantum simulation and quantum logic gates, where intense efforts have been devoted to improving the fidelity of two-qubit gates. We report our recent findings in constructing a different type of two-qubit controlled phase gate protocol with neutral atoms enabled by the Rydberg blockade, which aims at both robustness and high fidelity. It relies upon a modulated driving pulse with a specially tailored smooth waveform to gain appropriate phase accumulations for quantum gates. The major features include finishing a gate operation within a single pulse, not necessarily requiring individual site addressing, not being sensitive to the exact value of the blockade shift, and suppressing the population leakage error and rotation error. Building upon this progress, we further develop an upgrade in the form of dual-pulse off-resonant modulated driving with the major distinct feature of Doppler insensitivity, in order to address the challenge to the fidelity of two-qubit gates caused by residual thermal motion of the cold atoms. In principle, the gate fidelity remains reasonably high over a relatively significant velocity range of the qubit atoms. Moreover, we anticipate that this will inspire future improvements in gate protocols for other types of qubit platforms, and the strategies used here may find applications in the area of quantum optimal control.
关键词： Doppler insensitivity,controlled phase gate,quantum logic gates,neutral-atom arrays,Rydberg blockade,quantum simulation
更新于2025-09-23 15:19:57
-
[IEEE 2019 IEEE SENSORS - Montreal, QC, Canada (2019.10.27-2019.10.30)] 2019 IEEE SENSORS - Brillouin distributed fiber sensor based on a Dual-frequency laser
摘要： Electric ?elds can be effectively used to sense, manipulate, and move particles in lab-on-a-chip devices. Nevertheless, the throughput of such devices is a critical issue, which can be effectively improved by increasing the height of the microchannels. For this purpose, vertical electrodes are needed in order to apply electrical stimuli homogeneously over the full height of the channel. In this paper, we propose different fabrication processes based on a conformal coating of 3-D SU-8 structures with metal layers, de?ning vertical electrodes in micro?uidic channels with high aspect ratio and uniform coating of the vertical sidewalls. We describe two different strategies to achieve the patterning of connection lines inside the gaps of the pillar electrodes—one based on liftoff and the other based on dry ?lm resist. We show how the liftoff approach allows for high connection densities and high resolution of the patterning inside the 3-D electrode arrays. Moreover, we highlight how the dry ?lm process provides an ef?cient and low-cost alternative when neither high-density patterning nor high resolution is needed. Standard resistive and impedance measurements show high conductivity of the structures whose fabrication process grants standard photolithographic resolution in the de?nition of the electrode features.
关键词： vertical electrodes,microelectrode arrays,SU-8,3D microelectrodes,SU-8/PDMS bonding
更新于2025-09-23 15:19:57
-
Ti-MOF derived TixFe1-xOy Shells Boost Fe2O3 Nanorod Cores for Enhanced Photoelectrochemical Water Oxidation
摘要： TixFe1-xOy shells, in-situ formed from thermal treatment of a Ti-containing metal organic framework, NH2-MIL-125(Ti), significantly boost the photoelectrochemical water oxidation efficiency of Fe2O3 nanorod cores. The NH2-MIL-125(Ti) was coated on the surface of the Fe2O3 nanorods with a solvothermal process, followed by a two step calcination to afford the TixFe1-xOy shell/Fe2O3 core nanorod arrays. The TixFe1-xOy shell/Fe2O3 core nanorod array electrode exhibited much improved photoelectrochemical activities over the pristine Fe2O3 nanorod array electrode, boosting photo-current densities to 26.7 folds of that achieved by the pristine Fe2O3 nanorod array electrode at 1.23 V (vs. RHE) under illumination of simulated sun light of AM 1.5G. The success may be attributed to the much enhanced charge separation enabled by the hole trapping heterojunction of TixFe1-xOy shell/Fe2O3 core. The photoelectrochemical stability of the TixFe1-xOy shell/Fe2O3 core nanorod array electrode was excellent, retaining 98.9% of the initial photo-current density after a 5 hr continuous operation. This work is the first demonstration of MOF derived core-shell heterojunction for large improvements of PEC water splitting efficiencies, and can be readily extended to a wide range of catalyst design.
关键词： NH2-MIL-125(Ti),Fe2O3 nanorod,TixFe1-xOy shell/Fe2O3 core nanorod arrays,photoelectrochemical water oxidation,photoanode
更新于2025-09-23 15:19:57
-
Resonant modal analysis and dual-mode tailoring in high refractive index contrast two-dimensional nanorod arrays
摘要： Resonant modal analysis and dual-mode tailoring in high refractive index contrast two-dimensional (2-D) nanorod arrays are proposed. The specific modes of the guided mode resonances (GMRs) excited by the 2-D nanorod arrays can be distinguished based on the equivalent medium theory (EMT) and the analysis of the electric/magnetic fields. The broadband reflection and enhanced transmission can be obtained by the tailoring between the resonant dual-mode of the 2-D nanorod arrays. It is shown that the 2-D nanorod arrays can support the excitation of the resonant dual-mode with low-quality factor (low-Q) TM0 and high quality factor (high-Q) TE0 modes on a reflection broadband. The coupling of the edges of the resonant dual-mode can be tailored to create the resonant transmission with polarization independence near 1.31 μm. By merely changing the angle of incidence, one can achieve triple transmission channels due to the interaction of the nondegenerate resonant dual-modes.
关键词： Dual-mode tailoring,Modal analysis,Two-dimensional nanorod arrays,Guided mode resonance
更新于2025-09-23 15:19:57
-
Machine Learning Identification of the Sensing Descriptors Relevant in Molecular Interactions with Metal Nanoparticle-Decorated Nanotube Field-Effect Transistors
摘要： Carbon nanotube-based field-effect transistors (NTFETs) are ideal sensor devices as they provide rich information regarding carbon nanotube interactions with target analytes and have potential for miniaturization in diverse applications in medical, safety, environmental, and energy sectors. Herein, we investigate chemical detection with cross-sensitive NTFETs sensor arrays comprised of metal nanoparticle-decorated single-walled carbon nanotubes (SWCNTs). By combining analysis of NTFET device characteristics with supervised machine learning algorithms, we have successfully discriminated among five selected purine compounds – adenine, guanine, xanthine, uric acid, and caffeine. Interactions of purine compounds with metal nanoparticle-decorated SWCNTs were corroborated by density functional theory (DFT) calculations. Furthermore, by testing a variety of prepared, as well as commercial solutions with and without caffeine, our approach accurately discerns the presence of caffeine in 95% of the samples with 48 features using a linear discriminant analysis (LDA) and in 93.4% of the samples with only 11 features when using a support vector machine (SVM) analysis. We also performed recursive feature elimination and identified three NTFET parameters – transconductance, threshold voltage, and minimum conductance – as the most crucial features to analyte prediction accuracy.
关键词： support vector machine,linear discriminant analysis,sensor arrays,graphene,carbon nanotubes
更新于2025-09-23 15:19:57