Mohammad Faghri

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

This study presents an innovative lateral flow microfluidic paper-based analytical device (μPAD) designed for conducting quantitative paper-based enzyme-linked immunosorbent assays (p-ELISA), seamlessly executing conventional ELISA steps in a paper-based format. The p-ELISA device utilizes a passive fluidic circuit with functional elements such as...

This study presents an integrated approach to understanding fluid dynamics in Microfluidic Paper-Based Analytical Devices (µPADs), combining empirical investigations with advanced numerical modeling. Paper-based devices are recognized for their low cost, portability, and simplicity and are increasingly applied in health, environmental monitoring, a...

This work presents a dynamic modeling approach for analyzing the behavior of a bi-material cantilever actuator structure, consisting of a strip of filter paper bonded to a strip of tape. The actuator’s response is induced by a mismatch strain generated upon wetting, leading to the bending of the cantilever. The study delves into a comprehensive exp...

Analyses have been performed to obtain momentum and thermal characteristics in microchannel heat sinks. The applicability of existing correlations for friction factor and Nusselt number is investigated. The study revealed that existing correlations based on the analytical results can predict the heat sink performance to within the accuracy limits a...

This research explores the dynamics of a fluidically loaded Bi-Material cantilever (B-MaC), a critical component of µPADs (microfluidic paper-based analytical devices) used in point-of-care diagnostics. Constructed from Scotch Tape and Whatman Grade 41 filter paper strips, the B-MaC's behavior under fluid imbibition is examined. A capillary fluid f...

In this paper, the behavior of the Bi-Material Cantilever (B-MaC) response deflection upon fluidic loading was experimentally studied and modeled for bilayer strips. A B-MaC consists of a strip of paper adhered to a strip of tape. When fluid is introduced, the paper expands while the tape does not, which causes the structure to bend due to strain m...

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...

Experiments were conducted with nitrogen gas flow in two microtubes with constant wall temperature, made of stainless-steel and copper with diameters of 524 and 537 micrometers, to measure the total temperature at the inlet and outlet and quantitively determine the heat transfer rates. The temperature differences between the inlet and the wall were...

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...

Many previous studies used the performance factors for the evaluation of heat transfer enhancement of nanofluids under the identical pumping power. The validity of the performance factors was not examined yet. The validity of the performance factors used in previous studies examined considered only flows in a circular tube based on the empirical co...

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...

With the technological advancements in electronics, thermal management is becoming a concern that considerably affects the performance of electronic parts and systems, and two-phase immersion cooling is attracting attention due to its preferable cooling capacity. In immersion cooling, heat is dissipated by boiling that occurs on hot surfaces immers...

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...

Local friction factors of laminar and turbulent gas flows including choked flows through micro-tubes were experimentally investigated under atmospheric back pressure and variable inlet pressure. The experiments were carried out using two glass micro-tubes with D = 265.7 and 399.9 μm and a fused silica micro-tube with D = 531.2 μm. Two to three pres...

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...

There exists the laminar flow, transitional flow, turbulent flow and choked flow regimes in a microtube gas flow. Development of a non-invasive identification method of the flow regimes within a microdevice is expected. This paper demonstrated how the internal gas flow regimes can be identified by measuring the distribution of the external wall tem...

A micro-tube passage is a basic and important element in the design of micro heat exchangers and for this reason during the last decade a series of investigations have been made with the aim to clarify the main scaling effects playing an important role in microtubes. In this paper, a combined analysis of numerically and experimentally obtained aver...

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...

The energy equation which includes the substantial derivative of pressure and the viscous dissipation terms was solved numerically to verify whether it can correctly calculate the energy conversion from kinetic to thermal energy in an irreversible process. The fluid temperature was obtained for a swirling flow in a cylindrical container with a cons...

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...

A numerical analysis for the irreversible processes in an adiabatic piston-cylinder system was conducted using the Lam & Bremhorst low Reynolds number turbulence model (LB1) modified for compressible flows by Sarkar and Balakrishnan (LB1S model). Two-dimensional compressible momentum equation and energy equation which includes the substantial deriv...

A numerical analysis for the irreversible process in an adiabatic piston-cylinder system has been conducted. Axisymmetric compressible momentum and energy equations were solved numerically to obtain the state quantities of the system using the laminar flow model. The numerical method is based on the combined Implicit Continuous-fluid Eulerian techn...

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...

The SIMPLE algorithm for the pressure-velocity coupling has been adopted by many commercial and non-commercial CFD codes. The SIMPLE algorithm requires all normal velocities at the boundaries before solving the pressure correction equation. These velocities must imply an overall mass balance. In this paper, a new procedure to recalculate the outflo...

The conventional SIMPLE algorithm for the pressure–velocity coupling has been adopted by many commercial and non-commercial CFD codes. It encounters convergence problem when it is used to solve unsteady natural convection flows with zero-isothermal compressibility. In this paper, a modified version of this algorithm is proposed to remedy this drawb...

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...

In this paper we report the first three-dimensional (3D) and non-mechanical valve as a building block to create paper-based autonomous microfluidic devices. The valve consists of two layers of porous media that regulate flow direction. The valve also enables one fluid to gate another. By combining a single valve with 3D microchannels printed on pap...

A microfluidic valve system is disclosed that includes a matrix, a hydrophilic acceptor region a hydrophilic transfer region, and a hydrophobic gap between the acceptor region and the transfer region.

While sub-continuum heat conduction becomes more important as the size of micro/nanodevices keeps shrinking under the mean free path of heat carriers, its computation still remains challenging to the general engineering community due to the lack of easily accessible numerical simulation tools. To address this challenge, this article reports the fin...

In this paper, energy conserving Dissipative Particle Dynamics (DPDe) is used to study liquid characteristics when the walls are kept at a melting temperature. The formulation of the phase change problem is based on the latent heat model available in the literature. It is incorporated into the DPDe method to simulate a one-dimensional solid-liquid...

Currently, the Lateral flow Immunoassays (LFIAs) are not able to perform complex multi-step immunodetection tests because of their inability to introduce multiple reagents in a controlled manner to the detection area autonomously. In this research, a point-of-care (POC) paper-based lateral flow immunosensor was developed incorporating a novel micro...

The heat conduction in a two-dimensional square plate at nano/micro scales is investigated using numerical and semi-analytical methodologies which are energy conserving dissipative particle dynamics (DPDe) and Boltzmann transport equation (BTE) with the gray relaxation time approximation. The solution domain was considered to be a two-dimensional s...

Diffusive-ballistic heat transport in a two-dimensional square plate was simulated using energy conserving dissipative particle dynamics (DPDe). The solution domain was considered to be a two-dimensional square plate surrounded by walls at constant temperatures, where DPD particles are uniformly distributed. The effects of phonon mean free path was...

The liquid flow in sub-micron channels is simulated using multi-body dissipative particle dynamics (MDPD) to study the effect of the surface tension between liquid and wall surface on the flow in sub-micon scale. The solution domain is considered to be two-dimensional, where DPD particles are randomly distributed. Periodic boundary condition is emp...

Diffusive-ballistic heat transport in thin films was simulated using energy conserving dissipative particle dynamics (DPDe). The solution domain was considered to be two-dimensional and DPD particles were distributed in the solution domain uniformly under constant temperature boundary conditions at the top and bottom walls and periodic boundary at...

In this paper, we explore the possibility of improving the efficiency of Dean vortex-based mixers by only employing smooth-walled simple two-dimensional (2D) geometries. Numerical simulation results reveal that the symmetries of Dean flows in the prevalent “S-shaped” mixers can be broken up by adding a simple 180° turn between two consecutive curve...

The effect of nanoparticle volume fraction on hydrodynamic and thermally fully developed forced convection heat transfer in parallel-plate channels was numerically studied under constant wall temperature boundary condition using energy conserving dissipative particle dynamics (DPDe). The solution domain was considered to be two-dimensional with per...

This paper presents experimental results on flow characteristics of laminar, transitional and turbulent gas flows through microchannels. The experiments were performed for three microchannels etched into silicon wafers, capped with glass with hydraulic diameters of 69.48, 99.36 and 147.76 μm. The stagnation pressure was designated in such a way tha...

Current microfluidic paper-based devices lack crucial components for fluid manipulation. We created a fluidic diode fabricated entirely on a single layer of paper to control the wicking of fluids. The fluidic diode is a two-terminal component that promotes or stops wicking along a paper channel. We further constructed a trigger and a delay valve ba...

The effective thermal conductivity of Al2O3/water and CuO/water nanofluids were modeled by numerically solving steady heat flow in one-dimensional microchannels. This was accomplished by using energy conserving dissipative particle dynamics (DPDe).The effects of the interfacial thermal resistance and the Brownian motion of nanoparticles were incorp...

Compressible momentum and energy equations were solved numerically for concentric micro annular tubes with slip velocity and temperature jump wall boundary conditions. The results were expressed in the form of the product of friction factor and Reynolds number (fRe) for a quasi-fully developed condition and for the ranges of Re<1000 and Ma<1. The n...

Dissipative particle dynamics (DPD) was applied to fluid flow in irregular geometries using non-orthogonal transformation, where an irregular domain is transformed into a simple rectangular domain. Transformation for position and velocity was used to relate the physical and computational domains. This approach was described by simulating fluid flow...