Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Vishal Kaushik ◽  
Swati Rajput ◽  
Sulabh Srivastav ◽  
Lalit Singh ◽  
Prem Babu ◽  
...  

Abstract Miniaturized, low-cost wavelength detectors are gaining enormous interest as we step into the new age of photonics. Incompatibility with integrated circuits or complex fabrication requirement in most of the conventionally used filters necessitates the development of a simple, on-chip platform for easy-to-use wavelength detection system. Also, intensity fluctuations hinder precise, noise free detection of spectral information. Here we propose a novel approach of utilizing wavelength sensitive photocurrent across semiconductor heterojunctions to experimentally validate broadband wavelength detection on an on-chip platform with simple fabrication process. The proposed device utilizes linear frequency response of internal photoemission via 2-D electron gas in a ZnO based heterojunction along with a reference junction for coherent common mode rejection. We report sensitivity of 0.96 μA/nm for a broad wavelength-range of 280 nm from 660 to 940 nm. Simple fabrication process, efficient intensity noise cancelation along with heat resistance and radiation hardness of ZnO makes the proposed platform simple, low-cost and efficient alternative for several applications such as optical spectrometers, sensing, and Internet of Things (IOTs).


2014 ◽  
Vol 2014 (1) ◽  
pp. 000505-000510 ◽  
Author(s):  
A. Efimovskaya ◽  
A.M. Shkel

We present a novel approach for high-aspect ratio low resistance Thru-Wafer Interconnects for Double-Sided (TWIDS) fabrication of MicroElectroMechanical Systems (MEMS). The interconnects are formed by etching blind via holes in the handle substrate of an SOI (Silicon on Insulator) wafer, followed by filling the holes with copper, using sonic-assisted seedless copper electroplating process. This technique does not require additional conductive layer deposition, but utilizes a highly doped silicon device layer as a seed. The donut-shape gaps are etched around the copper filled vias to provide interconnects insulation. We introduced the fabrication process and characterized the performance of interconnects. Experimental analysis of an array of 22 interconnects demonstrated that the resistance values as low as 160 milli-Ohm can be achieved. Parasitic capacitance of interconnects is analytically calculated and the distortion of the MEMS resonator transduction spectrum is predicted using an equivalent circuit model. Signal amplitude and phase distortion due to the parasitic capacitance are estimated to be 1.15 dB and 5.96 deg, respectively, for the optimum 60 um diameter via with 35 um insulating gap. The method presented is compatible with an in-house folded MEMS fabrication process and may enable 3D folded TIMU (Timing Inertial Measurement Unit) structures with thru-wafer interconnects.


Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 770 ◽  
Author(s):  
Matej Vesenjak ◽  
Masatoshi Nishi ◽  
Toshiya Nishi ◽  
Yasuo Marumo ◽  
Lovre Krstulović-Opara ◽  
...  

The paper focuses on the fabrication of novel aluminium cellular structures and their metallographic and mechanical characterisation. The aluminium UniPore specimens have been manufactured by rolling a thin aluminium foil with acrylic spacers for the first time. The novel approach allows for the cheaper and faster fabrication of the UniPore specimens and improved welding conditions since a lack of a continuous wavy interface was observed in the previous fabrication process. The rolled assembly was subjected to explosive compaction, which resulted in a unidirectional aluminium cellular structure with longitudinal pores as the result of the explosive welding mechanism. The metallographic analysis confirmed a strong bonding between the foil surfaces. The results of the quasi-static and dynamic compressive tests showed stress–strain behaviour, which is typical for cellular metals. No strain-rate sensitivity could be observed in dynamic testing at moderate loading velocities. The fabrication process and the influencing parameters have been further studied by using the computational simulations, revealing that the foil thickness has a dominant influence on the final specimen geometry.


Author(s):  
Titus Hei Yeung Fong ◽  
Shahryar Sarkani ◽  
John Fossaceca

The challenge for Product Recall Insurance companies and their policyholders to manually explore their customer product’s defects from online customer reviews (OCR) delays product risk analysis and product recall recovery processes. In today's product life cycle, product recall events happen almost every day and there is no practical method to automatically transfer the massive amount of valuable online customer reviews, such as defect information, performance issue, and serviceability feedback, to the Product Recall Insurance team as well as their policyholders’ engineers to analyze the product risk and evaluate their premium. This lack of early risk analysis and defect detection mechanism often increases the risks of a product recall and cost of claims for both the insurers and policyholder, potentially causing billions of dollars in economic loss, liability resulting from the bodily injury, and loss of company credibility. This research explores two different kinds of Recurrent Neural Network (RNN) models and one Latent Dirichlet Allocation (LDA) topic model to extract product defect information from OCRs. This research also proposes a novel approach, combined with RNN and LDA models, to provide the insurers and the policyholders with an early view of product defects. The proposed approach first employs the RNN models for sentiment analysis on customer reviews to identify negative reviews and reviews that mention product defects, then applies the LDA model to retrieve a summary of key defect insight words from these reviews. Results of this research show that both the insurers and the policyholders can discover early signs of potential defects and opportunities for improvement when using this novel approach on eight of the bestselling Amazon home furnishing products. This combined approach can locate the keywords of these products’ defects and issues that customers mentioned the most in their OCRs, which allows the insurers and the policyholders to take required mitigation actions earlier, proactively stop the diffusion of the detective products, and hence lower the cost of claim and premium.


2021 ◽  
pp. 728-741
Author(s):  
Tao Liu ◽  
Yuanzi Zhou ◽  
Junzhong Bao ◽  
Xizhao Wang ◽  
Pengfei Zhang

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