42 research outputs found
Active Control Transmission of Terahertz Metamaterials Based on Ion Implantation and Light Pumping
Dynamic Adoption Model of Personalized Online Services with Privacy Concerns and WoM Effect
Privacy concern is becoming one of the most important issues for personalized online services like websites, computer software and mobile apps, especially those offered for free. In this paper, we develop a dynamic adoption model that combines new product diffusion theory with online services privacy, and seek to offer marketing strategies to maximize vendors’ profit for online services. We divide the diffusion process into two steps: awareness and adoption, and assume awareness process is mainly influenced by word of mouth effect. The adoption process occurs when benefits adjusted personal information demand level (PIDL) from vendors is lower or close to privacy disclosure tolerance level (PDTL) of consumers. We get numerical solutions for this optimal control problem with two differential equations. Our findings suggest WOM effect, network externalities and the initial state of awareness proportion are effective marketing tools for vendors, and parameters or variables like marginal value for consumer information (MVI), population size and the initial state of adoption amount are less effective. Our study should be considered preliminary with limitations and extensions for future research
Optimization of Substrate Conformal Imprint Lithography (SCIL) and Etching for Nanostructure
The UV-SCIL fabrication process was developed and optimized to improve the quality of the nanostructures on the hard substrate transferred with substrate conformal imprint lithography (SCIL) technology. In particular, the key steps such as coating imprint resist, exposure time and etching time were investigated thoroughly. The experiment’s results illustrate that imprint resist could well serve as an etching mask for the dry etching process without oxygen plasma. The optimized etching condition and SCIL technology could also be used to transfer nanostructures on different substrates for metal nanostructured biosensors or nanophotonics
Continuous blood separation utilizing spiral filtration microchannel with gradually varied width and micro-pillar array
A microfluidic separation device that uses the cross flow and the centrifugation effect to separate human plasma from whole blood has been designed, fabricated and evaluated. The chip mainly consists of a spiral channel divided into inner and outer microchannels by micropillar arrays, which are employed to filter blood cells and plasma. The major feature of this chip is that the width of the inner channel decreases gradually from the inlet Lathe outlet in order to increase the separation efficiency. Clogging and jamming in this filtration structure are efficiently alleviated. The performances of the separation device have been investigated theoretically and experimentally. Due to high purity of plasma and compact structure, this device can be used as either a plasma extraction device solely, or a pretreatment component that is integrated with other microfluidic device for point-of-care diagnostics. (C) 2012 Elsevier B.V. All rights reserved.http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000317152700018&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=8e1609b174ce4e31116a60747a720701Chemistry, AnalyticalElectrochemistryInstruments & InstrumentationSCI(E)12ARTICLE,SI122-12918
Theoretical study of terahertz active transmission line oscillator based on RTD-gated HEMT
In this paper, a new kind of terahertz oscillator is presented using plasma wave excitation in a resonant tunnel diode (RTD) gated high electron mobility transistor (HEMT). The plasma wave arising from the RTD-gated HEMT is equivalent to active transmission lines and induces negative differential conductance (NDC) of the oscillator. The proposed RTD-gated HEMT oscillator is more compact and has higher oscillation frequency than the transmission line loaded traditional RTD oscillator duo to plasma wave effect. This paper analyses and calculates the oscillation conditions, the relationships between device structures, oscillation frequency and the output power of the oscillator. The presented work may provide a new concept for fabricating terahertz oscillator
A Route to Terahertz Metamaterial Biosensor Integrated with Microfluidics for Liver Cancer Biomarker Testing in Early Stage
Abstract Engineered Terahertz (THz) metamaterials presented an unique characteristics for biosensing application due to their accurately tunable resonance frequency, which is in accord with vibrational frequency of some important biomolecules such as cancer biomarker. However, water absorption in THz regime is an obstacle to extend application in trace biomolecules of cancer antibody or antigen. Here, to overcome water absorption and enhance the THz biosensing sensitivity, two kinds of THz metamaterials biosensor integrated with microfluidics were fabricated and used to detect the Alpha fetoprotein (AFP) and Glutamine transferase isozymes II (GGT-II) of liver cancer biomarker in early stage. There were about 19 GHz resonance shift (5 mu/ml) and 14.2 GHz resonance shift (0.02524 μg/ml) for GGT-II and AFP with a two-gap-metamaterial, respectively, which agreed with simulation results. Those results demonstrated the power and usefulness of metamaterial-assisted THz spectroscopy in trace cancer biomarker molecular detection for biological and chemical sensing. Moreover, for a particular cancer biomarker, the sensitivity could be further improved by optimizing the metamaterial structure and decreasing the permittivity of the substrate. This method might be powerful and potential for special recognition of cancer molecules in the early stage