Constantine Anagnostopoulos

University of Rhode Island | URI · Department of Mechanical, Industrial and Systems Engineering

In this paper, we present a novel and cost-effective lab-on-paper microfluidics platform for performing ELISA autonomously, with no user intervention beyond adding the sample. The platform utilizes two Bi-Material Cantilever Valves placed in a specially designed housing. The integration of these valves in a specific channel network forms a complete...

The novel paper-based Bi-Material Cantilever (B-MaC) valve allows the autonomous loading and control of multiple fluid reagents which contributes to the accurate operation of paper-based microfluidic devices utilized for biological and chemical sensing applications. In this paper, an extensive parametric study is presented to evaluate the effects o...

The novel paper-based bi-material cantilever (B-MaC) valve allows the autonomous loading and control of multiple fluid reagents which contributes to the accurate operation of paper-based microfluidic devices were utilized to perform enzyme-linked immunosorbent assay (ELISA). This work delivers a platform with functional components fabricated on pap...

Paper-based microfluidic devices have demonstrated their capabilities of detecting low concentrations of analytes of interest in a variety of applications such as environmental monitoring, healthcare, food safety and have also found many other miscellaneous uses such as in portable fuel cells. The majority of these devices use colorimetric detectio...

Paper-based microfluidic devices have demonstrated their capabilities of detecting low concentrations of analytes of interest in a variety of applications such as environmental monitoring, healthcare, food safety and have also found many other miscellaneous uses such as in portable fuel cells. The majority of these devices use colorimetric detectio...

Paper-based microfluidic technology is a relatively new field of research that provides low-cost platforms and sensors for point-of-care diagnostics. While the majority of research in this field has been for biomedical applications, more and more paper-based devices and platforms are being designed and developed for environmental applications such...

The microfluidic paper-based analytical devices (μPADs) have witnessed a great extent of innovation over the past decade developing new components and materials assisting the diagnosis of different diseases and sensing of a wide range of biological, chemical, optical, and electrochemical phenomena. The novel paper-based cantilever (PBC) actuator is...

Paper-based microfluidic technology is a relatively new field of research that provides low-cost platforms and sensors for point-of-care diagnostics. While the majority of research in this field has been for biomedical applications, more and more paper-based devices and platforms are being designed and developed for environmental applications such...

Zinc and its compounds, alloys and composites play an important role in the modern day world and find application in almost every aspect that can im-prove the quality of our lives. This ranges from supplements and pharma-ceuticals that are meant to improve our health and wellbeing to additives meant to guard or reduce corrosion in metals. However,...

Nutrient pollution remains one of the greatest threats to water quality and imposes numerous public health and ecological concerns. Phosphate, the most common form of phosphorus, is one of the key nutrients necessary for plant growth. However, phosphate concentration in water should be carefully monitored for environmental protection requirements....

A brief description of our ongoing work in developing a practical system for nitrate detection in the field using our paper-based device.

Phosphorus is an essential nutrient for plant life which is most frequently found as phosphate in water. Once phosphate is found in abundance in surface water, a series of adverse effects on an ecosystem can be initiated. Therefore, a portable and reliable method is needed to monitor the phosphate concentrations in the field. In this paper, an inex...

Phosphorus is an essential nutrient for plant life which is most frequently found as phosphate in water. Once phosphate is found in abundance in surface water, a series of adverse effects on an ecosystem can be initiated. Therefore, a portable and reliable method is needed to monitor the phosphate concentrations in the field. In this paper, an inex...

As paper-based devices have been gaining interest over the past several years, so has the color analysis techniques broadly utilized for measuring signal intensity in colorimetric sensors. Therefore, it is critical to properly analyze the colored signal that forms so as to gain as much information as possible and properly characterize the concentra...

As paper-based devices have been gaining interest over the past several years, so has the color analysis techniques broadly utilized for measuring signal intensity in colorimetric sensors. Therefore, it is critical to properly analyze the colored signal that forms so as to gain as much information as possible and properly characterize the concentra...

Paper-based microfluidics provide a simple, inexpensive, and user friendly approach for a variety of applications, such as environmental monitoring, healthcare, food safety, and various other miscellaneous purposes. Paper-based devices are made up of several different sections and, depending on the application, may require the use of an actuator fo...

Paper-based microfluidics provide a simple, inexpensive, and user friendly approach for a variety of applications, such as environmental monitoring, healthcare, food safety, and various other miscellaneous purposes. Paper-based devices are made up of several different sections and, depending on the application, may require the use of an actuator fo...

Paper-based technology is a relatively new field that is seeing a lot of advancements. Several advancements can be used together to improve the detection efficiency or sensitivity of an analyte of interest. We have recently published some of the advancements we achieved in material and device architecture used for nitrate detection in water. In my...

In this paper, we report a simple and inexpensive paper-based microfluidic device for detecting nitrate in water. This device incorporates two recent developments in paper-based technology suitable for nitrate detection and has an optimized microfluidic design. The first technical advancement employed is an innovative fibrous composite material mad...

In this paper, we report a simple and inexpensive procedure to make a composite material of cellulose fibers with embedded zinc micoparticles. This fibrous material is produced by sedimentation and is referred to as “Zinculose”. Zinculose increases the surface contact area between a sample fluid and zinc microparticles. The effect of different para...

Herein, we report the development of a portable, iPhone controlled, and inexpensive infrared lightbox for improving the detection limits of paper-based phosphate devices. Commercial devices utilize the molybdenum blue protocol for phosphate detection. Although these devices are user-friendly and have a long shelf life, their standard mode of operat...

In this paper, we report the development of a portable and inexpensive infrared lightbox for improving the detection limits of paper-based phosphate devices. Commercial paper-based devices utilize the molybdenum blue protocol to detect phosphate in the environment. Although these devices are easy to use and have a long shelf life, their main defici...

Paper has been used as a platform for biological and chemical applications for over a century. Paper-based microfluidic devices have been gaining popularity over the past several years for the many advantages they provide, most notably their low cost, portability, ease of use and disposability. Paper-based microfluidic devices are made up of differ...

This presentation shows the proposed paper-based devices for detecting nitrate and nitrite in water. These devices will be cheap, user friendly and very easy to use. But most importantly, they will have a better detection limit for these nutrients than what is currently achieved using paper-based devices. The devices are made up of several segments...

Precise timing and sequential loading of multiple reagents is required to perform complex multistep immunoassays. Current paper-based lateral flow devices (LFDs) lack the crucial components, such as valves and actuators, for manipulation of reagents. Martinez et al. [1] reported a multilayer paper-based device that mechanically bridged discrete cha...

Interest in microfluidic paper-based devices for environmental monitoring and analysis has increased over the past several years due to the many advantages that these devices exhibit as compared to conventional analytical methods in use. Microfluidic paper-based devices allow for low-cost, easy-to-use, rapid and in-field detection of nutrients in w...

This study focuses on the development of a new paper based microfluidic device for the detection of Inter alpha Inhibitor Proteins (IαIP). The key development is on the application of fluidic actuated valves embedded in the paper that allow for sequential manipulation of the sample fluid and multiple reagents in a controlled manner to perform an EL...

The development of microfluidic paper-based devices for the detection of nitrate, nitrite and phosphate in water has been gaining interest in recent years. High concentrations of these nutrients in marine environments lead to unimpeded algal growth and low oxygen environments that are deadly for fish, shellfish, and invertebrates. Microfluidic pape...

This paper presents a new scheme for monitoring the sequential loading of reagents to a detection site to conduct biological assays. The automation of the sequential loading of biological reagents to a detection site is monitored by a lens-less charged couple device (CCD). The fluid handling system employs a custom edge detection algorithm to deter...

A printhead and a method of manufacturing a printhead are provided. The printhead includes a polymeric substrate including a surface. Portions of the polymeric substrate define a liquid chamber. A material layer is disposed on the surface of the polymeric substrate. Portions of the material layer define a nozzle bore. The nozzle bore is in fluid co...

We present a numerical model that simulates the evolution of precipitates and the diffusion of interstitial oxygen in Czochralski silicon. The growth and/or dissolution of each precipitate and the local concentration of interstitial oxygen with which the precipitates interact are followed as a function of time. We treat realistic densities of discr...

Continuous Inkjet (CIJ) printing technology offers an ideal solution to meet the growing demands of the commercial digital printing market because of its advantages in speed, cost, and reliability. Here we present progress on the development of a new integrated CIJ printhead that can be batch manufactured using standard silicon microfabrication and...

We present a novel CMOS/MEMS microfluidic device that enables the controlled production and redirection of streams of picoliter-sized droplets at frequency rates in the hundreds of kilohertz range. Droplet generation and jet manipulation are achieved using voltage-controlled thermal modulation, at modest temperatures and with no moving elements. We...

Application specific integrated circuits (ASICs), also called custom ICs, are chips specially designed to (1) perform a function that cannot be done using standard components, (2) improve the performance of a circuit, or (3) reduce the volume, weight, and power requirement and increase the reliability of a given system by integrating a large number...

We present the architecture and fabrication method of a fluidic device with increased droplet deflection. The device is capable of producing picoliter size droplets precisely and steering them. The precision is a consequence of the reproducibility of the nozzles that are made using VLSI technology and tools. In addition, the droplet size is determi...

A new method is reported for deflecting a microscopic jet emanating from a nozzle away from the nozzle's axis of symmetry. It relies on putting energy into the jet through an asymmetric heater embedded in the nozzle. This novel phenomenon is probed theoretically. It is shown that jet deflection is set by the competition among three effects. Two of...

Summary form only given. This paper presents the outcomes of a Workshop titled `Technological Literacy Counts': which was held October 9-10, 1998 in Baltimore, MD, USA. A goal of the Workshop was to establish a working and partnering relationship between engineers and precollege (K-12) educators. The Workshop was a two-day, highly participative and...

Educators have been struggling to improve the math and science proficiency and technological literacy of US primary and secondary school students for more than 40 years-with meager results. But many new initiatives at the local, state, and national levels offer new hope for turning the tide. Some of these initiatives are described

A smart-power integrated circuit has been developed intended for low-cost, medium power switching, and drive applications. The die incorporates CMOS digital control logic and bipolar drivers, with BiCMOS interface between the two technologies. Modeling and optimization of process and circuit parameters resulted in a 7.66 mm² chip with fo...

Reviews the use of cell libraries and assembly tools for application-specific integrated circuits (ASIC's). To illustrate the design process the authors describe the construction of cells suitable for 1.2-3- mu m CMOS and BiCMOS IC's, and the use of silicon assembly tools for use with these libraries. The digital library discussed was developed fro...

A VLSI program at the University of Hawaii initiated in 1987 is discussed. Since this time, the curriculum has been expanded to offer undergraduate classes in analog and digital VLSI design. The expansion and development of this new curriculum are described

The authors describe the use of software that was developed as part of a research program in analog CMOS integrated circuit design for an undergraduate course on analog VLSI design. The software includes some unusual uses of readily available, inexpensive, and easy-to-use programs available for microcomputers such as Macintosh or IBM-PC clones. Alt...

Efforts to improve the tools and techniques for designing an analog cell library for analog/digital VLSI design are described. The techniques presented allow an analog IC designer to construct a library for cell-based design, as opposed to direct compilation of a full-custom analog/digital IC. Using this approach, the problem of automation is made...

Low-frequency noise measurements on both enhancement mode and depletion mode n-channel devices are presented. The results demonstrate that flicker noise fellows McWhorter's tunneling model in enhancement mode MOSFETs (metal-oxide-semiconductor field-effect transistors). In the depletion mode device, the flicker noise follows McWhorter's tunneling m...

A description is given of a digital-video-signal postprocessing chip (DSPP) developed for use with one-chip color video image sensors. The chip improves the image quality of reconstructed RGB data by performing black-level adjustment, color correction matrixing, gamma correction, and edge enhancement. It contains 115000 transistors in a 11.5 mm×11....

A 2/3" format 1.4 megapixel full-frame CCD image sensor with a cell size of 6.8×6.8μ m, that achieves a quantum efficiency of 50% at 550nm, will be disclosed. Output-amplifier noise is 15rms electrons. Amplifier uses buried channel LDD NMOSFETs. Input-referred sensitivity is 15μV/electron over a 71MHz bandwidth. Device has been fabricated using a t...

Replacing aluminum with tungsten silicide in Al/SiO 2 /Al/Si double‐metal systems reduced hillock formation and allowed the reflow of glass for better second‐metal topography. The high contact resistance of tungsten silicide to n⁺‐Si and poly‐Si was reduced by implanting the tungsten silicide with phosphorus or arsenic. Charge‐coupled‐de...

The Monte Carlo method is used to evaluate the extent of the crosstalk in solid-state imagers. The calculations are performed in three dimensions and are in excellent agreement with experiment. The Monte Carlo method is used because it handles adjacent regions that either collect or reflect minority carriers.

Isolated vertical n-p-n transistors were fabricated by a modified 5-/spl mu/m n-well CMOS process. The modification included a decrease in the p/SUP +/ source and drain implant dose and an increase in the final anneal time, but no extra processing steps of masks were required. The n-p-n transistors had generally good characteristics, with H/SUB FE/...

Internal gettering can be used to reduce crosstalk in imagers and latchup susceptibility in CMOS circuits. The internal gettering process forms defects in the bulk of the silicon wafers that are effective recombination sites for minority carriers in the substrate. Experimental and theoretical results are presented for crosstalk reduction obtained i...

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The lateral diffusion of photoelectrons to adjacent picture elements in a silicon linear photodiode array is reduced in substrates with a high density of oxygen precipitates formed by internal gettering. The signal due to diffusion in adjacent pixels, normalized to the illuminated pixel signal, was reduced by a factor of 1.6 for pixels with centers...

Solid-state imagers lose resolution when photocarriers generated in one imaging site diffuse to a nearby site where they are collected. These processes are modeled by solving the steady-state diffusion equation for minority carriers. A source term represents the absorption of photons and the generation of photocarriers, and a linear term represents...

We describe a solid-state sensor for image recording at frame rates up to 2000 full or 12 000 partial frames per second (fps). The sensor consists of a 192 V × 248 H array of photocapacitors. For high-speed operation the image-sensing area is divided into 6 blocks, each with 32 parallel outputs. The blocks are addressed sequentially, and the 32 out...

Thin polysilicon electrodes can be used in frame-transfer CCD imagers to improve their sensitivity in the blue region of the spectrum. The optical constants of the thin, heavily doped films were measured. The quantum efficiency of 4-phase CCD image sensors was accurately predicted from these optical constants. The sheet resistance as a function of...

An analysis is presented that relates the photogenerated charge collected in one element of a charge-injection device imaging array to the voltage readout corresponding to that element. A linear relationship results when a voltage sensing amplifier is used. Crosstalk is found to occur, however, when a portion of the array is illuminated above satur...

The collection process of the photogenerated charge in charge-injection device (CID) image sensors is examined and a method is presented by which the collection efficiency can be calculated. Numerical techniques are utilized in the analysis. The method is applied to a specific epitaxial type structure. The contribution of the depleted and undeplete...

Polycrystalline silicon films are presently used as the semitransparent gate electrodes in front-illuminated charge-coupled device (CCD) and charge-injection device (CID) image sensors. The transmittance of air/SiO/SUB 2//polysilicon/SiO/SUB 2//Si structures is calculated in spectral region between 0.4 and 1.0 /spl mu/. A proper choice of the thick...

Investigation of the dependence of the photocurrent generated in silicon p-n junctions on the energy of the incident photons to obtain details concerning the fine structure in the indirect optical-absorption edge of silicon. It is found that at room temperature there are three prominent thresholds in the absorption tail. The first, which is not too...

Pre-college engineering and technology programs are not immune from the increased demands that advances in technology have placed upon them. The International Technology Education Association (ITEA), and its Technology for All Americans Project, has recently published Standards for Technological Literacy: Content for the Study of Technology1. These...