Sponge and graphene/PVDF /ZnO composite based 3D stacked flexible multi-sensor platform

MRS Advances ◽  
2016 ◽  
Vol 2 (6) ◽  
pp. 341-347
Author(s):  
Parikshit Sahatiya ◽  
P Thanga Gomathi ◽  
S Solomon Jones ◽  
Sushmee Badhulika
Keyword(s):  
Sensor Array ◽  
Pvdf Film ◽  
Wearable Electronics ◽  
Large Area ◽  
Casting Method ◽  
Array Platform ◽  
Sensing Applications ◽  
Sensor Platform ◽  
Pencil Lead ◽  
Copper Tape

AbstractIn this work, we propose a multi-sensor platform where sensors are stacked over one another (3D stacked) each offering a unique functionality. The technique involves the use of Polyurethane (PU) sponge and PVDF/graphene (Gr) /ZnO composites for various sensing applications. The sponge was made conductive by dipping it in different weight percentages of pencil lead dispersed in ethanol through ultrasonication. Large area Gr/PVDF films were fabricated by simple solution mixing and casting method which also served as a substrate for the 3D stacked sensor. ZnO was grown hydrothermally over Gr/PVDF film by masking a portion of Gr/PVDF film to form a p-n junction. Silver paste and copper tape were used as contact pads. All the three fabricated devices were stacked with PU sponge sandwiched between Gr/PVDF/ZnO (top) and large area Gr/PVDF (bottom) as substrate. Performance of individual sensors and 3D stacked sensor was compared and no notable change was observed. The 3D stacked sensor array platform with its multifunctionality would be a step ahead in wearable electronics which can be integrated on human and can function as an e-skin for burn and acid victims, robotics and human-machine interactions.

scholarly journals Large-Area Thermal Distribution Sensor Based on Multilayer Graphene Ink

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5188
Author(s):  
Tomi Koskinen ◽  
Taneli Juntunen ◽  
Ilkka Tittonen
Keyword(s):  
Signal To Noise Ratio ◽  
Graphene Film ◽  
Multilayer Graphene ◽  
Wearable Electronics ◽  
Large Area ◽  
Sensor Applications ◽  
Thermal Distribution ◽  
Sensing Applications ◽  
Detection Of Objects ◽  
Distribution Mapping

Emergent applications in wearable electronics require inexpensive sensors suited to scalable manufacturing. This work demonstrates a large-area thermal sensor based on distributed thermocouple architecture and ink-based multilayer graphene film. The proposed device combines the exceptional mechanical properties of multilayer graphene nanocomposite with the reliability and passive sensing performance enabled by thermoelectrics. The Seebeck coefficient of the spray-deposited films revealed an inverse thickness dependence with the largest value of 44.7 μV K−1 at 78 nm, which makes thinner films preferable for sensor applications. Device performance was demonstrated by touch sensing and thermal distribution mapping-based shape detection. Sensor output voltage in the latter application was on the order of 300 μV with a signal-to-noise ratio (SNR) of 35, thus enabling accurate detection of objects of different shapes and sizes. The results imply that films based on multilayer graphene ink are highly suitable to thermoelectric sensing applications, while the ink phase enables facile integration into existing fabrication processes.

Computer simulation study about the dependence of amorphous silicon photonic waveguides efficiency on the material quality

2020 ◽  
Vol 90 (3) ◽  
pp. 30502
Author(s):  
Alessandro Fantoni ◽  
João Costa ◽  
Paulo Lourenço ◽  
Manuela Vieira
Keyword(s):  
Amorphous Silicon ◽  
High Throughput Screening ◽  
Simulation Analysis ◽  
Low Cost ◽  
Deposition Process ◽  
Large Area ◽  
Sidewall Roughness ◽  
Sensing Applications ◽  
Fabrication Defects ◽  
The Impact

Amorphous silicon PECVD photonic integrated devices are promising candidates for low cost sensing applications. This manuscript reports a simulation analysis about the impact on the overall efficiency caused by the lithography imperfections in the deposition process. The tolerance to the fabrication defects of a photonic sensor based on surface plasmonic resonance is analysed. The simulations are performed with FDTD and BPM algorithms. The device is a plasmonic interferometer composed by an a-Si:H waveguide covered by a thin gold layer. The sensing analysis is performed by equally splitting the input light into two arms, allowing the sensor to be calibrated by its reference arm. Two different 1 × 2 power splitter configurations are presented: a directional coupler and a multimode interference splitter. The waveguide sidewall roughness is considered as the major negative effect caused by deposition imperfections. The simulation results show that plasmonic effects can be excited in the interferometric waveguide structure, allowing a sensing device with enough sensitivity to support the functioning of a bio sensor for high throughput screening. In addition, the good tolerance to the waveguide wall roughness, points out the PECVD deposition technique as reliable method for the overall sensor system to be produced in a low-cost system. The large area deposition of photonics structures, allowed by the PECVD method, can be explored to design a multiplexed system for analysis of multiple biomarkers to further increase the tolerance to fabrication defects.

scholarly journals Anisotropic, Wrinkled, and Crack-Bridging Structure for Ultrasensitive, Highly Selective Multidirectional Strain Sensors

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Heng Zhang ◽  
Dan Liu ◽  
Jeng-Hun Lee ◽  
Haomin Chen ◽  
Eunyoung Kim ◽  
...  
Keyword(s):  
Rational Design ◽  
Full Range ◽  
Human Motion ◽  
Strain Sensors ◽  
Gauge Factor ◽  
Wearable Electronics ◽  
Trade Off ◽  
Human Motion Detection ◽  
Sensing Applications ◽  
Anisotropic Structures

AbstractFlexible multidirectional strain sensors are crucial to accurately determining the complex strain states involved in emerging sensing applications. Although considerable efforts have been made to construct anisotropic structures for improved selective sensing capabilities, existing anisotropic sensors suffer from a trade-off between high sensitivity and high stretchability with acceptable linearity. Here, an ultrasensitive, highly selective multidirectional sensor is developed by rational design of functionally different anisotropic layers. The bilayer sensor consists of an aligned carbon nanotube (CNT) array assembled on top of a periodically wrinkled and cracked CNT–graphene oxide film. The transversely aligned CNT layer bridge the underlying longitudinal microcracks to effectively discourage their propagation even when highly stretched, leading to superior sensitivity with a gauge factor of 287.6 across a broad linear working range of up to 100% strain. The wrinkles generated through a pre-straining/releasing routine in the direction transverse to CNT alignment is responsible for exceptional selectivity of 6.3, to the benefit of accurate detection of loading directions by the multidirectional sensor. This work proposes a unique approach to leveraging the inherent merits of two cross-influential anisotropic structures to resolve the trade-off among sensitivity, selectivity, and stretchability, demonstrating promising applications in full-range, multi-axis human motion detection for wearable electronics and smart robotics.

scholarly journals Wide range and highly linear signal processed systematic humidity sensor array using Methylene Blue and Graphene composite

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Muhammad Umair Khan ◽  
Gul Hassan ◽  
Rayyan Ali Shaukat ◽  
Qazi Muhammad Saqib ◽  
Mahesh Y. Chougale ◽  
...  
Keyword(s):  
Methylene Blue ◽  
Linear Combination ◽  
Linear Function ◽  
Humidity Sensor ◽  
Sensor Array ◽  
Combination Method ◽  
Humidity Sensing ◽  
Sensing Applications ◽  
Wide Range ◽  
Graphene Flakes

AbstractThis paper proposes a signal processed systematic 3 × 3 humidity sensor array with all range and highly linear humidity response based on different particles size composite inks and different interspaces of interdigital electrodes (IDEs). The fabricated sensors are patterned through a commercial inkjet printer and the composite of Methylene Blue and Graphene with three different particle sizes of bulk Graphene Flakes (BGF), Graphene Flakes (GF), and Graphene Quantum Dots (GQD), which are employed as an active layer using spin coating technique on three types of IDEs with different interspaces of 300, 200, and 100 µm. All range linear function (0–100% RH) is achieved by applying the linear combination method of nine sensors in the signal processing field, where weights for linear combination are required, which are estimated by the least square solution. The humidity sensing array shows a fast response time (Tres) of 0.2 s and recovery time (Trec) of 0.4 s. From the results, the proposed humidity sensor array opens a new gateway for a wide range of humidity sensing applications with a linear function.

Fabrication of large area nanogap electrodes for sensing applications

2013 ◽  
Vol 1530 ◽  
Author(s):  
A. Bendavid ◽  
L. Wieczorek ◽  
R. Chai ◽  
J. S. Cooper ◽  
B. Raguse
Keyword(s):  
Large Scale ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Beam Current ◽  
Fabrication Method ◽  
Large Area ◽  
Sensor Applications ◽  
Sensing Applications ◽  
Lift Off ◽  
Nanogap Electrodes

ABSTRACTA large area nanogap electrode fabrication method combinig conventional lithography patterning with the of focused ion beam (FIB) is presented. Lithography and a lift-off process were used to pattern 50 nm thick platinum pads having an area of 300 μm × 300 μm. A range of 30-300 nm wide nanogaps (length from 300 μm to 10 mm ) were then etched using an FIB of Ga+ at an acceleration voltage of 30 kV at various beam currents. An investigation of Ga+ beam current ranging between 1-50 pA was undertaken to optimise the process for the current fabrication method. In this study, we used Monte Carlo simulation to calculate the damage depth in various materials by the Ga+. Calculation of the recoil cascades of the substrate atoms are also presented. The nanogap electrodes fabricated in this study were found to have empty gap resistances exceeding several hundred MΩ. A comparison of the gap length versus electrical resistance on glass substrates is presented. The results thus outline some important issues in low-conductance measurements. The proposed nanogap fabrication method can be extended to various sensor applications, such as chemical sensing, that employ the nanogap platform. This method may be used as a prototype technique for large-scale fabrication due to its simple, fast and reliable features.

Zinc Oxide and Copper Oxide Nanostructures: Fundamentals and Applications

2012 ◽  
Vol 1406 ◽  
Author(s):  
Magnus Willander ◽  
Omer Nur ◽  
Gul Amin ◽  
A. Zainelabdin ◽  
S. Zaman
Keyword(s):  
Zinc Oxide ◽  
Copper Oxide ◽  
Light Emitting Diodes ◽  
Zno Nanorods ◽  
Superior Performance ◽  
Zno Nanostructures ◽  
Large Area ◽  
Light Emitting ◽  
Sensing Applications ◽  
Quality Material

ABSTRACTCopper oxide (CuO) and zinc oxide (ZnO) nanostructures complement each other since CuO is unintentional p-type and ZnO unintentional n-type. Using the low temperature chemical growth approach, the effect on morphology of varying the pH of the grown ZnO nanostructures and CuO micro structures is monitored. For both materials the variation of the pH was found to lead to a large variation on the morphology achieved. The grown ZnO NRs and CuO micro flowers material were used to fabricate devices. We demonstrate results from ZnO nanorods (NRs)/polymer p-n hybrid heterojunctions chemically grown on paper and using a process on paper for light emitting diodes (LEDs) applications as well as some large area light emitting diodes LEDs. The growth of CuO micro flowers indicated good quality material for sensing applications. The grown CuO micro flowers were employed as pH sensors. The results indicated a superior performance as expect due to the catalytic properties of this material.

scholarly journals The Fabrication of Nanostructures on Polydimethylsiloxane by Laser Interference Lithography

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 73 ◽  
Author(s):  
Jun Wu ◽  
Zhaoxin Geng ◽  
Yiyang Xie ◽  
Zhiyuan Fan ◽  
Yue Su ◽  
...  
Keyword(s):  
Indium Tin Oxide ◽  
Splitting Method ◽  
Vertical Direction ◽  
Interference Lithography ◽  
Wearable Electronics ◽  
Laser Interference Lithography ◽  
Laser Interference ◽  
Large Area ◽  
Periodic Nanostructures ◽  
Ito Glass

We report a method for fabricating periodic nanostructures on the surface of polydimethylsiloxane (PDMS) using laser interference lithography. The wave-front splitting method was used for the system, as the period and duty cycle can be easily controlled. Indium tin oxide (ITO) glass reveals favorable characteristics for controlling the standing waves distributed in the vertical direction, and was selected as the rigid substrate for the curing of the PDMS prepolymer, photoresist spin coating, and exposure processes. Periodic nanostructures such as gratings, dot, and hole arrays were prepared. This efficient way of fabricating large area periodic nanoscale patterns will be useful for surface plasmonic resonance and wearable electronics.

Fabricaton Ofactive Devices and Logic Gates on Fibers

2003 ◽  
Vol 769 ◽  
Author(s):  
YongWoo Choi ◽  
Ioannis Kymissis ◽  
Annie Wang ◽  
Akintunde I. Akinwande
Keyword(s):  
Threshold Voltage ◽  
Electronic Structures ◽  
Low Cost ◽  
Logic Gates ◽  
Wearable Electronics ◽  
Drain Voltage ◽  
Large Area ◽  
Active Devices ◽  
P Type ◽  
A Current

AbstractTextiles are a suitable substrate for large area, flexible and wearable electronics because of their excellent flexibility, mechanical properties and low cost manufacturability. The ability to fabricate active devices on fiber is a key step for achieving large area and flexible electronic structures. We fabricated transistors and inverters with a-Si film and pentacene film on Kapton film and cut them into fibers. The a-Si TFT showed a threshold voltage of 8.5 V and on/off ratio of 103 at a drain voltage of 10 V. These are similar to the characteristics of a TFT fabricated on a glass substrate at the same time. The maximum gain of the inverter with an enhancement n-type load was 6.45 at a drain voltage of 10 V. The pentacene OTFT showed a threshold voltage of -8 V and on/off ratio of 103 at a drain voltage of -30 V. The inverter with a depletion p-type load showed a voltage inversion but the inversion occurred at the wrong voltage. The antifuse was successfully programmed with a voltage pulse and also a current pulse. The resistance decreased from 10 GΩ to 2 kΩ after the programming.

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