High-Sensitivity Conjugated Polymer/Nanoparticle Nanocomposites for Infrared Sensor Applications

2011 ◽  
Author(s):  
Kung-Hwa Wei
2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Jung Joon Lee ◽  
Srinivas Gandla ◽  
Byeongjae Lim ◽  
Sunju Kang ◽  
Sunyoung Kim ◽  
...  

Abstract Conformal and ultrathin coating of highly conductive PEDOT:PSS on hydrophobic uneven surfaces is essential for resistive-based pressure sensor applications. For this purpose, a water-based poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) solution was successfully exchanged to an organic solvent-based PEDOT:PSS solution without any aggregation or reduction in conductivity using the ultrafiltration method. Among various solvents, the ethanol (EtOH) solvent-exchanged PEDOT:PSS solution exhibited a contact angle of 34.67°, which is much lower than the value of 96.94° for the water-based PEDOT:PSS solution. The optimized EtOH-based PEDOT:PSS solution exhibited conformal and uniform coating, with ultrathin nanocoated films obtained on a hydrophobic pyramid polydimethylsiloxane (PDMS) surface. The fabricated pressure sensor showed high performances, such as high sensitivity (−21 kPa−1 in the low pressure regime up to 100 Pa), mechanical stability (over 10,000 cycles without any failure or cracks) and a fast response time (90 ms). Finally, the proposed pressure sensor was successfully demonstrated as a human blood pulse rate sensor and a spatial pressure sensor array for practical applications. The solvent exchange process using ultrafiltration for these applications can be utilized as a universal technique for improving the coating property (wettability) of conducting polymers as well as various other materials.


Fiber optic has extraordinary properties and is suitable in sensor applications due to its special potential. Currently, macro bending characteristics of newly developed hetero core fiber optic element are designed and evaluated. This paper presents the preliminary results obtained from the numerical simulation analysis of the bending sensitivity of U-shape fiber optics toward the 2D electromagnetic wave in terms of mesh, curvature radius, core fiber size, and turn number. Fiber optics with core sizes of 4, 9, 50, and 62.5 μm were designed. In addition, the combination of core diameters 50-4-50, 50-9-50, 62.5-4-62.5, and 62.5-9-62.5 μm is evaluated to compare the outcome of transmission power in terms of hetero core structure of fiber optic. Simulation is performed using COMSOL Multiphysics simulation tool. The developed U-shape fiber optic is designed to sense the distortion of reducing power transmission by comparing input and output power. Results show that the selected mesh depends on the size of geometry bending fiber optics, and fine and finer mesh is the best for U-shape fiber optic. Furthermore, the power flow on the fiber decreases with the decreasing curvature radius and increasing turn number. The fiber with a core size combination of 62.5–4–62.5 um has high sensitivity in terms of loss. The attained results possess higher potential in the field of sensor applications, such as displacement, strain, pressure, and monitoring respiration, on human body. This study serves as a basis for further investigation of nanomaterial coating on fiber optics, thereby enhancing its credibility for sensing.


2018 ◽  
Vol 28 (23) ◽  
pp. 1707548 ◽  
Author(s):  
Emin Istif ◽  
Javier Hernández-Ferrer ◽  
Esteban P. Urriolabeitia ◽  
Anastasios Stergiou ◽  
Nikos Tagmatarchis ◽  
...  

ChemPhysChem ◽  
2017 ◽  
Vol 18 (10) ◽  
pp. 1308-1316 ◽  
Author(s):  
Arnab Ghosh ◽  
Bikash Jana ◽  
Sourav Maiti ◽  
Rajesh Bera ◽  
Hirendra N. Ghosh ◽  
...  

1997 ◽  
Vol 488 ◽  
Author(s):  
Biwang Jiang ◽  
Shailesh Sahay ◽  
Wayne E. Jones

AbstractWe have synthesized a novel conjugated polymer containing terpyridine receptors. This conjugated, polymer-based fluorescent chemosensory system exhibits unusually high sensitivity toward transition metal ions (∼-10−9 M). The fluorescence quenching response of the terpyridine containing conjugated polymer to transition metal ions is related to a facile energy migration in which energy from absorption of a photon, can migrate through the conjugated polymer system and be quenched by trapping sites. Terpyridine receptors can readily bind to transition metal ions and create a low lying Metal to Ligand Charge Transfer (MLCT) state which can act as an excitation trap.


2014 ◽  
Vol 174 ◽  
pp. 357-367 ◽  
Author(s):  
Lynn Dennany ◽  
Zahera Mohsan ◽  
Alexander L. Kanibolotsky ◽  
Peter J. Skabara

Electrochemiluminescence (ECL) uses redox reactions to generate light at an electrode surface, and is gaining increasing attention for biosensor development due to its high sensitivity and excellent signal-to-noise ratio. ECL studies of monodisperse oligofluorene–truxenes (T4 series) have been reported previously, showing the production of stable radical cations and radical anions, generating blue ECL. The compound in this study differs from the original structures, in that there are 2,1,3-benzothiadazole (BT) units inserted between the first and second fluorene units of the quarterfluorenyl arms. It was therefore anticipated that the incorporation of these highly luminescent and ECL-active compounds into sensor development would lead to significant decreases in detection limits. In this contribution, we report on the impact of incorporating these novel complexes into sensor devices on the ECL efficiency, as well as the ability of these to improve the detection sensitivity and decrease the limit of detection using the reagent-free detection of model analytes. The real world impact of these compounds is elucidated through the comparison with more standard ECL materials such as ruthenium-based compounds. The potential for multiple applications is to be examined within this contribution.


2001 ◽  
Vol 708 ◽  
Author(s):  
Soo-Hyoung Lee ◽  
Bon-Cheol Ku ◽  
X. Wang ◽  
L.A. Samuelson ◽  
J. Kumar

ABSTRACTThis work describes the synthesis and electrospinning of new fluorescent polymers and their use for the fabrication of optical chemical sensors. A new fluorescent monomer was first synthesized by coupling reactions between methacryloyl chloride and a pyrene derivative, 1-pyrene butanol. Fluorescent polymers containing pyrene molecules were then obtained by the copolymerization of this monomer with methylmethacrylate using 2,2'-azobisisobutyronitrile as the initiator. These polymers show distinct and well-defined fluorescence that is characteristic of the pyrene chromophores. Electrospinning was used to process these polymers into high surface area nanofibrous membranes for optical sensing. The resulting membranes show a high sensitivity to 2,4-dinitro toluene based on the fluorescence quenching of the pyrene chromophores. Fluorescence intensities decreased with increasing concentration of the 2,4-dinitro toluene. The quenching behavior follows Stern-Volmer bimolecular quenching kinetics. The synthesis, characterization, electrospinning fabrication, and sensing capability of these polymers will be discussed.


2017 ◽  
Vol 7 ◽  
pp. 184798041773764 ◽  
Author(s):  
Yoshitaka Fujimoto

Graphene is expected to be a potential device material for sensor applications due to its high charge mobility and high sensitivity to adsorbates. This article reviews the first-principles density-functional study that clarifies gas adsorption effects on graphene layers doped with boron and nitrogen atoms. We show adsorption effects of not only common gas molecules but also environmentally polluting or toxic gas molecules on stabilities and structural properties of graphene layers and carbon nanotubes. We also show physical properties induced by the adsorption of the gas molecules and discuss the possibility to detect these gas molecules.


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