Fast, Highly Sensitive Interdigitated Capacitor Sensor to Detect Wide Range of Temperatures Using Graphene-Oxide-Containing Dielectric Membrane

2018 ◽  
Vol 18 (7) ◽  
pp. 2667-2674 ◽  
Author(s):  
Md. Rajibur Rahaman Khan ◽  
Shin-Won Kang
Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1468
Author(s):  
Sangheon Jeon ◽  
Jihye Lee ◽  
Rowoon Park ◽  
Jeonghwa Jeong ◽  
Min Chan Shin ◽  
...  

Patterning of surfaces with a simple strategy provides insights into the functional interfaces by suitable modification of the surface by novel techniques. Especially, highly ordered structural topographies and chemical features from the wide range of interfaces have been considered as important characteristics to understand the complex relationship between the surface chemistries and biological systems. Here, we report a simple fabrication method to create patterned surfaces over large areas using evaporative self-assembly that is designed to produce a sacrificial template and lithographic etch masks of polymeric stripe patterns, ranging from micrometer to nanoscale. By facilitating a roll-on-plate geometry, the periodically patterned surface structures formed by repetitive slip-stick motions were thoroughly examined to be used for the deposition of the Au nanoparticles decorated graphene oxide (i.e., AuNPs, ~21 nm) and the formation of conductive graphene channels. The fluorescently labeled thiol-modified DNA was applied on the patterned arrays of graphene oxide (GO)/AuNPs, and biotin-streptavidin sensitive devices built with graphene-based transistors (GFETs, effective mobility of ~320 cm2 V−1 s−1) were demonstrated as examples of the platform for the next-generation biosensors with the high sensing response up to ~1 nM of target analyte (i.e., streptavidin). Our strategy suggests that the stripe patterned arrays of polymer films as sacrificial templates can be a simple route to creating highly sensitive biointerfaces and highlighting the development of new chemically patterned surfaces composed of graphene-based nanomaterials.


Synthesis ◽  
2021 ◽  
Author(s):  
Alexandre Desaintjean ◽  
Fanny Danton ◽  
Paul Knochel

A wide range of polyfunctionalized di(hetero)aryl- and dialkenyl-magnesium reagents were prepared in toluene within 10 to 120 min between −78 °C and 25 °C via an I/Mg- or Br/Mg-exchange reaction using reagents of the general formula R2Mg (R = sBu, Mes). Highly sensitive functional groups, such as a triazene or a nitro group, were tolerated in these exchange reactions, enabling the synthesis of various functionalized (hetero)arenes and alkenes derivatives after quenching with several electrophiles including allyl bromides, acyl chlorides, aldehydes, ketones, and aryl iodides.


Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 279
Author(s):  
Kentaro Noda ◽  
Jian Sun ◽  
Isao Shimoyama

A tensor sensor can be used to measure deformations in an object that are not visible to the naked eye by detecting the stress change inside the object. Such sensors have a wide range of application. For example, a tensor sensor can be used to predict fatigue in building materials by detecting the stress change inside the materials, thereby preventing accidents. In this case, a sensor of small size that can measure all nine components of the tensor is required. In this study, a tensor sensor consisting of highly sensitive piezoresistive beams and a cantilever to measure all of the tensor components was developed using MEMS processes. The designed sensor had dimensions of 2.0 mm by 2.0 mm by 0.3 mm (length by width by thickness). The sensor chip was embedded in a 15 mm3 cubic polydimethylsiloxane (PDMS) (polydimethylsiloxane) elastic body and then calibrated to verify the sensor response to the stress tensor. We demonstrated that 6-axis normal and shear Cauchy stresses with 5 kPa in magnitudes can be measured by using the fabricated sensor.


2021 ◽  
Vol 7 (2) ◽  
pp. 48
Author(s):  
Vittorio Scardaci ◽  
Giuseppe Compagnini

Laser scribing has been proposed as a fast and easy tool to reduce graphene oxide (GO) for a wide range of applications. Here, we investigate laser reduction of GO under a range of processing and material parameters, such as laser scan speed, number of laser passes, and material coverage. We use Raman spectroscopy for the characterization of the obtained materials. We demonstrate that laser scan speed is the most influential parameter, as a slower scan speed yields poor GO reduction. The number of laser passes is influential where the material coverage is higher, producing a significant improvement of GO reduction on a second pass. Material coverage is the least influential parameter, as it affects GO reduction only under restricted conditions.


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