Andrew Steckl

Andrew Steckl
University of Cincinnati | UC · Department of Electrical Engineering and Computer Science

PhD

About

491
Publications
63,278
Reads
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13,463
Citations
Additional affiliations
January 1988 - present
University of Cincinnati
Position
  • Ohio Eminent Scholar, Carl Gieringer Professor
Description
  • Director, Nanoelectronics Laboratory
August 1976 - December 1987
Rensselaer Polytechnic Institute
Position
  • Director, Center for Integrated Electronics

Publications

Publications (491)
Article
Full-text available
Properties of pH‐responsive electrospun nanofibers incorporated with biocompatible/degradable Carbopol, commonly used in pharmaceuticals and personal care products, are reported. Sonication of Carbopol dispersions prior to electrospinning leads to uniform incorporation into fibers of the host polymer polyvinylpyrrolidone. The hydration behavior is...
Article
Aim: Microneedles create micro-punctures and deliver drugs or nutrients deep into skin layer. We demonstrated that microneedles, coated with electrosprayed nanoparticles loaded with functional molecules, are useful for transdermal delivery. Methods: Electrospraying was utilized to generate drug loaded nanoparticles and to create uniform coating on...
Article
Hormones produced by glands in the endocrine system and neurotransmitters produced by the nervous system control many bodily functions. The concentrations of these molecules in the body are an indication of its state, hence the use of the term biomarker. Excess concentrations of biomarkers, such as cortisol, serotonin, epinephrine, dopamine, are re...
Article
Bacteria are one of the most common sources of illness, responsible for a wide range of infections. Bacterial infections can be caused from a variety of sources, with thousands of deaths attributed to waterborne outbreaks alone [ 1 ]. Detection of both infectious and non-infectious bacteria is utilized to ensure commercial goods and water are safe...
Article
Electronics and photonics have a long and successful history of combining to provide many devices and products that are at the heart of the modern technological world, ranging form solar cells to lasers to digital displays. In this presentation I will first give a brief historical overview of the interplay and interdependence of electronics and pho...
Article
We present a rapid and quantitative point-of-care (PoC) system based on a smartphone application that is capable of accurately tracking the flow of red blood cells (RBCs) through a no-reaction lateral flow assay (nrLFA) device. Utilizing only the camera feed from the smartphone and built-in image processing, the nrLFA is identified and RBC fluid fl...
Article
Floating gastro-retentive delivery systems can prolong the gastric residence providing sustained drug release. In this study, we report on self-inflating effervescence-based electrospun nanofibers embedding polyethylene oxide/sodium bicarbonate cast films. In this system, sodium bicarbonate results in an effervescence effect by creating carbon diox...
Article
A lateral flow assay using DNA aptamer-based sensing for the detection of dopamine in urine is reported. Dopamine duplex aptamers (hybridized sensor with capture probe) are conjugated to 40-nm Au nanoparticles (AuNPs) with 20T linkers. The detection method is based on the dissociation of the duplex aptamer in the presence of dopamine, with the sens...
Article
Full-text available
Interstitial chemotherapy plays a pivotal role in the treatment of glioblastoma multiforme (GBM), an aggressive form of primary brain cancer, by enhancing drug biodistribution to the tumor and avoiding systemic toxicities. The use of new polymer structures that extend the release of cytotoxic agents may therefore increase survival and prevent recur...
Article
Full-text available
The cover feature shows the versatility of coaxial electrospinning in forming fibers with complex structures. Polymer solutions are fed into a nozzle with concentric openings from which a coaxial liquid jet is extracted by the application of an electric field. The resulting core–sheath fibers with nano/micrometer diameter are formed with a variety...
Article
Full-text available
The formation of fibers by electrospinning has experienced explosive growth in the past decade, recently reaching 4,000 publications and 1,500 patents per year. This impressive growth of interest is due to the ability to form fibers with a variety of materials, which lend themselves to a large and rapidly expanding set of applications. In particula...
Article
A new aptamer-based lateral flow strip assay has been designed and developed for on-site rapid detection of cortisol in sweat. Cortisol in sweat has been identified as a key biomarker to monitor physiological stress. A highly sensitive and specific cortisol sensor was achieved by conjugating cortisol-selective aptamers to the surface of gold nanopa...
Article
Full-text available
Blood is the most intensely studied human biofluid and is used as the main indicator (so-called “gold standard”) of the health status of the individual. Blood is also a very complex fluid, containing a multiplicity of components, including cells and cell fragments (red and white blood cells, platelets), proteins, and many other organic molecules. L...
Article
Full-text available
Correction for ‘Correcting the effect of hematocrit in whole blood coagulation analysis on paper-based lateral flow device’ by Hua Li et al. , Anal. Methods , 2018, DOI: 10.1039/c8ay00192h.
Article
A simple method to correct the effect of hematocrit (Hct) on a paper-based lateral flow assay (LFA) device that is designed to assess whole blood coagulation is reported. By quantifying...
Article
Premature ripening of fruits and senescence of vegetables caused by ethylene gas (a natural aging hormone) imposes significant wastage during packaging, transport, and storage. We report on packaging membranes, produced by electrospinning, that act as efficient carriers for potassium permanganate, a salt widely used for oxidizing alkenes such as et...
Article
Increasing numbers of animals are diagnosed with thromboembolism, requiring anticoagulation treatment to prevent thrombotic events. Frequent and periodic coagulation monitoring is critical to ensure treatment effectiveness and patient safety by limiting blood coagulation ability within the desired therapeutic range. Point-of-care diagnostics is an...
Article
Core-sheath fibers using different Eudragit materials were successfully produced and their controlled multi-pH responses have been demonstrated. Coaxial fibers made of Eudragit L 100 (EL100) core and Eudragit S 100 (ES100) sheath provide protection and/or controlled release of core material at pH 6 by adjusting the sheath thickness (controlled by t...
Article
There are only two chemotherapeutic agents that are approved by US Food and Drug Administration (FDA) for treatment of newly diagnosed glioblastoma. Gliadel wafer implantation was approved in 2003 as it improved survival in newly diagnosed glioblastoma patients. However, Gliadel wafer use is currently topic of controversy given its toxicity profile...
Article
Full-text available
Vitamin K antagonists such as warfarin are the most widely used class of oral anticoagulants. Due to a narrow therapeutic window, patients on warfarin require regular monitoring. Self-testing using point-of-care (POC) diagnostic devices is available, but cost makes this monitoring method beyond reach for many. The main objective of this research wa...
Article
Core-sheath fibers containing a drug for brain tumor are reported. Mycophenolic acid (MPA), a FDA-approved immunosuppressant, has been demonstrated to inhibit several types of tumor cells growth. However, the effective serum MPA concentration for anti-tumor declines quickly in-vivo due to degradation in the liver, which hampers the development of M...
Article
The first self-immolative polymer (SIP) nanofiber membrane have been demonstrated in this report, which the immolation can be triggered by external stimulus. Electrospun SIP/PAN fibers provide ~ 25 times quicker and more responsive depolymerization (i.e. immolation) than a cast film in the triggering condition. Depolymerization of SIP in the SIP/PA...
Article
The “no reaction” lateral flow assay (nrLFA) uses a simplified LFA structure with no conjugate pad and no stored reagents. In the nrLFA, the capillary-based transport time or distance is the key indicator, rather than the outcome of a biochemical reaction. Hence, the calibration and reproducibility of the nrLFA device are critical. The capillary fl...
Article
Statement of significance: The increase in drug resistant pathogens has driven the need for alternative treatments that are effective against resistant bacteria and do not contribute to drug resistance. Nisin is an excellent model bacteriocin for antimicrobials because of its size and mode of action, and has been extensively used as FDA-approved f...
Article
Full-text available
A lab-on-chip vehicle was explored combining RF near field communication (NFC) harvested power and light sources for paper-based lateral flow immunoassay systems (LFIA) with quantum dots (QD) as fluorophores. Such a vehicle has potential applications in point-of-care systems requiring high sensitivity while also being low-cost, disposable and easy...
Article
Full-text available
A self-powered urinalysis platform for point of care utility is reported consisting of an electrochemical sensor fabricated on paper substrate and powered by urine. A galvanic cell activates upon addition of urine, with the REDOX reaction between urine and electrode–electrolyte pair Al|NaOH|NaCl|CuSO4|Cu generating power. Owing to presence of many...
Conference Paper
Full-text available
https://www.interpore.org/images/8th_conference/abstracts/Final_program_May_10.pdf
Article
The integration of organic light emitting diodes (OLEDs) as excitation light sources for quantum dot-based fluorescent lateral flow immunoassay systems (LFIA) was investigated. This approach has the potential to deliver a sensitive visible detection scheme for low-cost, disposable lab-on-chip point-of-care (POC) diagnosis system. Thin film phosphor...
Article
Full-text available
Magnetic beads with ~1.9 µm average diameter were used to transport microliter volumes of liquids between contiguous liquid segments with a tube for the purpose of investigating phase change of those liquid segments. The magnetic beads were externally controlled using a magnet, allowing for the beads to bridge the air valve between the adjacent liq...
Article
Electrospun polyacrylonitrile (PAN) based carbon nanofibers (CNFs) have attracted intense attention due to their easy processing, high carbon yield and robust mechanical properties. In this work, a CNF modified glassy carbon (GC) electrode that was coated with Nafion polymer was evaluated as a new electrode material for the simultaneous determinati...
Conference Paper
Full-text available
http://www.mrs.org/57th-emc/
Article
Organic light-emitting diodes (OLED) fabricated from all "natural" materials will lead to renewable, sustainable, and potentially inexpensive organic optoelectronics. Achieving this goal will require reimagining all the various aspects of the OLED with natural-based renewable materials. Here, we replace the common substrate, electrode, and hole inj...
Article
Full-text available
This paper is a review of the recent research in bio-based materials for electronic applications. It will highlight work on ionic conductivity of deoxyribonucleic acid (DNA) based membranes, enhancement of direct current and photoconductivity of DNA, crosslinking of DNA, electrical and Raman characterization of DNA-based films fabricated by a drawd...
Article
Naturally occurring biomolecules have increasingly found applications in organic electronics as a low cost, performance-enhancing, environmentally safe alternative. Previous devices, which incorporated DNA in organic light emitting diodes (OLEDs), resulted in significant improvements in performance. In this work, nucleobases (NBs), constituents of...
Article
Microbial fuel cells (MFCs) are an alternative electricity generating technology and efficient method for removing organic material from wastewater. Their low power densities, however, hinder practical applications. A primary limitation in these systems is the anode. The chemical makeup and surface area of the anode influences bacterial respiration...
Article
Full-text available
We report on the use of nucleic acid bases (NBs) in organic light emitting diodes (OLEDs). NBs are small molecules that are the basic building blocks of the larger DNA polymer. NBs readily thermally evaporate and integrate well into the vacuum deposited OLED fabrication. Adenine (A) and thymine (T) were deposited as electron-blocking/hole-transport...
Article
Full-text available
A simple approach to the evaluation of blood coagulation using a microfluidic paper-based lateral flow assay (LFA) device for point-of-care (POC) and self-monitoring screening is reported. The device utilizes whole blood, without the need for prior separation of plasma from red blood cells (RBC). Experiments were performed using animal (rabbit) blo...
Article
Magnetic beads (MBs) with ~ 1.9 µm average diameter have been used to transport specific microliter-scale volumes of liquids between adjacent reservoirs within a closed tube under the influence of a magnetic field. The tube inner surface is coated with a hydrophobic layer, enabling the formation of a surface tension valve by inserting an air gap be...
Article
This paper is a review of the recent research in bio-based materials for photonics and electronics applications. Materials that we have been working with include: deoxyribonucleic acid (DNA)-based biopolymers and nucleobases. We will highlight work on increasing the ionic conductivity of DNA-based membranes, enhancing the direct (DC) current and ph...
Article
Full-text available
Pentacene-based organic thin-film transistors (OTFTs) were fabricated on several types of flexible substrate: commercial photo paper, ultra-smooth specialty paper and ultra-thin (100 μM) flexible glass. The transistors were fabricated entirely through dry-step processing. The transconductance and field-effect mobility of OTFTs on photo paper reache...
Article
Full-text available
Organic light-emitting diodes (OLED) were fabricated on flexible and transparent reconstituted cellulose obtained from wood pulp. Cellulose is naturally available, abundant, and biodegradable and offers a unique substrate alternative for the fabrication of flexible OLEDs. Transparent cellulose material was formed by dissolution of cellulose in an o...
Article
Full-text available
A simple and affordable method of evaluating blood coagulation ability using microfluidic paperbased lateral flow assay (LFA) device is reported. Rabbit whole blood treated with citrate as anticoagulant was used in experiments. Re-establishment of blood coagulation cascade and creation of different coagulation abilities were achieved by adding CaCl...
Article
Phase shift epitaxy (PSE) is a periodic growth scheme, which desynchronizes host material growth process from dopant incorporation, allowing independent optimization. p-type doping of GaN with Mg by PSE is accomplished with molecular beam epitaxy by periodic shutter action (in order to iterate between Ga- and N-rich surface conditions) and by adjus...
Article
Fluorinated polymers, the most extensively used hydrophobic surface materials for electrowetting (EW) devices, are expensive and have potential risks to health and environment. In this paper, EW devices fabricated with non-fluorinated hydrophobic surfaces are demonstrated by using a polysiloxane-modified polyacrylate (BYK® Silclean® 3700, Louisvill...
Article
Full-text available
In previous research we have demonstrated improvements in device performance with the incorporation of a deoxyribonucleic acid (DNA)-based biopolymer into organic light emitting diodes, organic thin film transistors and other organic photonic and electronic devices. Here, we investigate nucleobases, nitrogen-containing biological compounds found wi...
Article
Full-text available
Versatile electrowetting (EW) arrays were fabricated with small to large pixels, on fixed glass and flexible polymer substrates, for smart window applications. EW prototypes on glass substrates were constructed with pixel sizes ranging from 50 μm×150 μm to 2 mm×2 mm. The dosing of the array with colored oil was achieved by dip coating the substrate...
Article
As discussed in the accompanying articles in this issue of MRS Bulletin , the optical properties of rare-earth (RE) elements have led to many important photonic applications, including solid-state lasers, components for telecommunications (optical-fiber amplifiers, fiber lasers), optical storage devices, and displays. In most of these applications,...
Patent
Full-text available
Methods for electrospinning a hydrophobic coaxial fiber into a superhydrophobic coaxial fiber mat can include providing an electrospinning coaxial nozzle comprising a core outlet coaxial with a sheath outlet, ejecting an electrospinnable core solution from the core outlet of the electrospinning coaxial nozzle, ejecting a hydrophobic sheath solution...
Article
Full-text available
A novel dual drug delivery system is presented using triaxial structured nanofibers, which provides different release profiles for model drugs separately loaded in either the sheath or the core of the fiber. Homogenous, coaxial and triaxial fibers containing a combination of materials (PCL, polycaprolactone; PVP, polyvinylpyrrolidone) were fabricat...
Article
In this work, a microfabricated anode based on gold coated poly(ϵ-caprolactone) fiber was developed that outperformed gold microelectrode by a factor of 2.65-fold and even carbon paper by 1.39-fold. This is a result of its ability to three-dimensionally interface with bacterial biofilm, the metabolic “engines” of the microbial fuel cell (MFC). We a...
Article
Mobile display devices that use ultra-thin (≤100 µm) glass substrates offer a combination of attractive characteristics: lightweight, high quality device fabrication process, thermal and dimensional stability, and mechanical flexibility. Electrowetting (EW) devices fabricated on ultra-thin glass are demonstrated in this paper. Water contact angle,...
Article
You wake up with a heavy head. Was it the half dozen glasses of champagne last night or are you getting sick? In your bathroom is a little strip of paper that can tell you for sure. You place it on your tongue and after a few seconds, you pull it back to see the bad news: There's a small green dot next to the word "flu." When you fish your doctor's...
Conference Paper
Full-text available
Driven by increasing concerns over the energy-climate crisis and environment pollution, microbial fuel cells (MFCs) have been a major focus for renewable energy production. With the successful validation of conceptual macro-sized MFCs as a low-cost renewable energy technology, recent research has focused on miniaturizing MFCs for powering small por...
Article
Electronic readers that use rugged flexible substrates potentially offer very attractive characteristics (low-cost processing, lightweight, mechanical flexibility, etc.) and could expand the explosive growth of e-reader devices. In this paper, we demonstrate electrowetting (EW) devices fabricated on flexible substrates, including paper, polymers (p...
Article
Full-text available
Nanofibers consisting of the bulk heterojunction organic photovoltaic (BHJ–OPV) electron donor–electron acceptor pair poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester (P3HT:PCBM) are produced through a coaxial electrospinning process. While P3HT:PCBM blends are not directly electrospinnable, P3HT:PCBM-containing fibers are produced in a...
Article
Non-woven, high surface area photocatalytic cellulosic electrospun fibers were fabricated for solar-light-driven water treatment purposes and tested for photocatalytic decomposition of the potent cyanobacteria toxin microcystin-LR (MC-LR). Electrospun fibers of cellulose acetate were converted to succinylated cellulose and then loaded with titania...
Article
A combination of nonpolymerizable phospholipids (DPPC or DPhPC) and a smaller amount of cross-linking photopolymerizable phospholipids (23:2 DiynePC) is incorporated in an unsupported artificial lipid bilayer formed using the droplet interface bilayer (DIB) approach. The DIB is formed by contacting lipid monolayer-coated aqueous droplets against ea...
Article
Continuous wave (CW) back-scattered sum-frequency generation (SFG) and second harmonic generation (SHG) have been obtained from GaN and SiC. GaN samples were obtained from GaN films grown by molecular-beam epitaxy (MBE), metalorganic chemical-vapor deposition and hydride vapor-phase epitaxy. The SiC samples were obtained from 3C SiC/Si grown by che...
Article
With research in the area of superconductivity growing, it is no surprise that new efforts are being made to induce superconductivity or increase transition temperatures (Tc) in carbon given its many allotropic forms. Promising results have been published for boron doping in diamond films, and phosphorus doping in highly oriented pyrolytic graphite...
Article
The drive to improve the performance and reduce the cost of electronic, photonic and fluidic devices is starting to focus on the use of materials that are exotic for these applications but actually readily available in other fields. In this talk the use of paper in biochip and other applications will be reviewed. Paper is a very attractive material...
Article
Droplet interface bilayer is a versatile approach that allows formation of artificial lipid bilayer membrane at the interface of two lipid monolayer coated aqueous droplets in a lipid filled oil medium. Versatility exists in the form of voltage control of DIB area, ability of forming networks of DIBs, volume control of droplets and lipid-oil, and e...
Article
The authors report on the luminescence properties of Er doped GaN grown prepared by metalorganic molecular beam epitaxy (MOMBE) and solid-source molecular beam epitaxy (SSMBE) on Si substrates. Both types of samples emitted characteristic 1.54 m PL resulting from the intra-4f Er{sup 3+} transition I I. Under below-gap excitation the samples exhibit...
Article
The coaxial electrospinning technique was investigated as a novel method to create stabilized, enzyme-containing fibers that have the potential to provide enhanced protection from chemical agents. Electrospinning is a versatile technique for the fabrication of polymer fibers with large length (cm to km): diameter (nm to μm) aspect ratios. The large...
Article
The process of creating natural DNA-containing bio-organic light emitting diodes is a fascinating journey from salmon fish to the highly-efficient BiOLED. DNA from salmon sperm is used as a high-performance electron blocking layer, to enhance the efficiency of the BiOLED over its conventional OLED counterpart. An overview of the BiOLED fabrication...
Article
The emerging field of DNA photonics is making inroads in the development of optical waveguides, organic LED and laser structures. The DNA polymer in solid-state thin-film form has a unique combination of optical and electronic properties, which have formed the basis of the new field of DNA photonics. Researchers are also combining DNA with light-em...
Article
Electrospun fibers consisting of poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonate) (PEDOT/PSS) and poly(ethylene oxide) (PEO) have been used to successfully encapsulate and stabilize thylakoid membrane vesicles isolated from spinach. Light-driven electronic properties were measured. Fibers with immobilized thylakoids show higher electrical c...
Article
A new approach to color displays promises to combine the look and feel of paper with video speed for e-paper applications on flat and pliable substrates. Electronic readers, with their attractive functionality, are a rapidly growing market despite shortcomings of the most commonly used e-paper technology, electrophoretic displays (EPDs). 1 The limi...
Article
Highly aligned microstrip patterns consisting of biaxial CaF 2 nanorods have been successfully self-assembled by simply using capillary pressure. The alignment direction of the microstrips is perpendicular to the flux direction during nanorod growth. Aligning behavior and pattern width can be controlled by changing wetting time and surface tension...
Article
A novel approach to control the area of anchor-free droplet interface bilayer (DIB) lipid membranes is presented. Unsupported DIB lipid membranes are formed at the interface of phospholipid-coated aqueous droplets dispensed in dodecane oil. Using electrodes inserted into the droplets, an external voltage is applied which modulates the effective DIB...
Article
Room temperature visible and IR light electroluminescence (EL) has been obtained from Er-doped GaN Schottky barrier diodes. The GaN was grown by molecular beam epitaxy on Si substrates using solid sources (for Ga and Er) and a plasma source for N 2 . Transparent contacts utilizing indium tin oxide were employed. Strong green light emission was obse...
Article
We report the morphological and compositional characteristics of Er-doped GaN grown by MBE on Si(111) substrates and their effect on optical properties. The GaN was grown by molecular beam epitaxy using solid sources (for Ga and Er) and a plasma gas source for N2. The films emit by photoexcitation in the visible and near infrared wavelengths from t...
Article
Site-selective combined excitation emission spectroscopy studies have been performed on Eu-doped GaN and numerous sites have been identified. Relative numbers and broadening of these peaks has been investigated for different growth conditions and for increasing AL content of the Al x Ga 1-x N alloy.
Article
Raman scattering has been used to characterize lattice damage and impurity-induced compositional disordering in AlGaAs superlattice suitable for optical waveguiding. The degree of damage induced by both conventional ion beam (CIB) implantation and focused ion beam (FIB) implantation is studied using a spatial correlation model to interpret the Rama...
Article
Patterned SiC/Si heterostructures have been treated by anodic etching in HF/ethanol solutions at 25°C. The anodic process used a current density ranging from 2-10 mA/cm2 and times from 2-5 min. The SiC/Si samples had SiC regions and exposed Si regions of dimensions from 2.5 μm to ∼500 gm. For μm substrates, short etching times (≥3 min) result in se...
Article
Si thin films were deposited on quartz at temperatures ( TD ) ranging from 540 to 640°C. X-ray diffraction indicates that films deposited at TD < 580°C are amorphous, while those deposited above 600°C are poly-crystalline with a <220> texture. The Si films were made porous by stain-etching in HF:HNO3:H2O. Only Si films deposited at 590°C and above...
Article
In this paper the nucleation mechanisms for SiC thin film growth are studied by rapid thermal CVD and atomic force microscopy (AFM). The nucleation mode was found to be strongly dependent on the hydrocarbon partial pressure in the gas stream, for a fixed reaction time. In the case of three-dimensional (island) growth at low precursor concentration,...
Article
The effect of Si doping on the formation of stain-etched porous Si and its photoluminescent properties was studied. Porous Si is obtained by purely chemical etching of crystalline Si in a solution of HF:HNO3:H2O in the ratio of 1:3:5. We have observed that an incubation time (ti) exists between the insertion of Si into the solution and the onset of...
Article
The effect of the incorporation and annealing of deuterium in 3C-SiC on its photoluninescence is reported. A 3C-SiC crystal has been implanted with 100 keV deuterium and subsequently annealed at temperatures between 1015 °C and 1220 °C for 1 to 5 minutes. SIMS depth profiles indicate hydrogen is strongly trapped by defects generated through ion bom...
Article
Results are presented on FIB mixing of an Al0.3Ga0.7As/GaAs superlattice with equal 3.5 nm barrier and well widths. Si++ was accelerated to 100 kV and implanted parallel to sample normal at doses ranging from 1013 to 1015/cm2. The level of inter-layer disordering was measured primarily by Auger depth profiling. The mixing effect of RTA-only increas...