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.

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.

Extending WLCSP Packaging Technology Capabilities to Enable Miniaturized Sensor and MEMS Packaging Applications

2016 ◽  
Vol 2016 (DPC) ◽  
pp. 000397-000420
Author(s):  
Ted Tessier
Keyword(s):  
Smart Phone ◽  
Cost Effective ◽  
Wearable Electronics ◽  
Wafer Level ◽  
Technology Infrastructure ◽  
Sensor Applications ◽  
Mems Sensor ◽  
Sensing Applications ◽  
Communication Devices ◽  
Multiple Sensor

WLCSP has been widely deployed in portable computing and communication devices for efficient die level packaging of integrated semiconductor and integrated passive applications. More recently with the proliferation of smart phone capabilities and applications as well as the emergence of Internet of Things and Wearable Electronics, MEMS and sensor devices in minimized package formats have become increasingly pervasive. These include image sensors, light sensors, finger print sensors as well as accelerometer, gyroscope and other MEMS motion sensing devices. It is predicted that the widespread adoption of WLCSP packaging for sensing applications will accelerate the proliferation of the incorporation of multiple sensor technologies within future communication devices. A number of these MEMS/Sensor applications have been able to leverage the existing WLCSP technology infrastructure and has led to opportunities to packaging and cost-effective standardization and miniaturization. On the other hand, some significant new changes to WLCSP process flows have also emerged that have had to be addressed. This paper will provide an overview of MEMS and Sensor applications that are currently or will use 2D, 2.5D or 3D wafer level packaging formats. Process enhancements including the ability to process thinner substrates with the adoption of temporary carrier technologies will also be highlighted.

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.

Plasma Oxidation Followed by Vapor Removal for Enhancing Intactness of Transferred Large-Area Graphene

2020 ◽  
Vol 12 (8) ◽  
pp. 1252-1260
Author(s):  
Pan Zhang ◽  
Xiaojun Dai ◽  
Li-Ping Wu ◽  
Huaqiang Cai ◽  
Jing-Gang Gai
Keyword(s):  
Polymethyl Methacrylate ◽  
Chemical Vapor ◽  
Multilayer Graphene ◽  
Wearable Electronics ◽  
Photovoltaic Devices ◽  
Large Area ◽  
Display Devices ◽  
Chemical Vapor Deposited ◽  
Potential Applications ◽  
Wide Potential

Transfering large-area graphene from the metal substrate to the target substrate is crucial to its wide potential applications in electromagnetic shielding, supercapacitor, DNA sequencing, seawater desalination, wearable electronics devices, display devices for OLEDs and touch-screen. Polymethyl methacrylate assisted transfer is being widely adopted, however, this technique tends to destroy graphene and to produce polymethyl methacrylate residues on the graphene surface. Here, we reduced the damage of graphene by improving the hydrophilicity and adhesion of graphene and substrate using O2 plasma followed by heat treatment, and removed the polymethyl methacrylate residuals on the surface of graphene using hot acetone vapor. Both monolayer and multilayer graphene stacks were transferred onto the target substrate with dramatically improved surface hydrophilicity (contact angle decreased from 57.8° to 6.0°), and neither damage nor undesired residues were found. Especially, in the whole test band (400–1100 nm), all transferred graphene stacks exhibited transmittances higher than 90%. This work may bring opportunities for exploitation of large-area chemical-vapor-deposited graphene in wider transparent and ultra-thin photovoltaic devices fields.

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 Rapid Growth of TiO2 Nanoflowers via Low-Temperature Solution Process: Photovoltaic and Sensing Applications

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 566 ◽  
Author(s):  
M. Akhtar ◽  
Ahmad Umar ◽  
Swati Sood ◽  
InSung Jung ◽  
H. Hegazy ◽  
...  
Keyword(s):  
Low Temperature ◽  
Anatase Phase ◽  
Three Dimensional ◽  
Solution Process ◽  
Dye Sensitized Solar Cell ◽  
Sensor Applications ◽  
Dye Sensitized ◽  
Sensing Applications ◽  
Density Growth ◽  
Temperature Solution

This paper reports the rapid synthesis, characterization, and photovoltaic and sensing applications of TiO2 nanoflowers prepared by a facile low-temperature solution process. The morphological characterizations clearly reveal the high-density growth of a three-dimensional flower-shaped structure composed of small petal-like rods. The detailed properties confirmed that the synthesized nanoflowers exhibited high crystallinity with anatase phase and possessed an energy bandgap of 3.2 eV. The synthesized TiO2 nanoflowers were utilized as photo-anode and electron-mediating materials to fabricate dye-sensitized solar cell (DSSC) and liquid nitroaniline sensor applications. The fabricated DSSC demonstrated a moderate conversion efficiency of ~3.64% with a maximum incident photon to current efficiency (IPCE) of ~41% at 540 nm. The fabricated liquid nitroaniline sensor demonstrated a good sensitivity of ~268.9 μA mM−1 cm−2 with a low detection limit of 1.05 mM in a short response time of 10 s.

scholarly journals Vertical monolithic integration of wide- and narrow-bandgap semiconductor nanostructures on graphene films

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Youngbin Tchoe ◽  
Janghyun Jo ◽  
HoSung Kim ◽  
Heehun Kim ◽  
Hyeonjun Baek ◽  
...  
Keyword(s):  
Graphene Film ◽  
Monolithic Integration ◽  
Hybrid Nanostructures ◽  
Dual Wavelength ◽  
Multilayer Graphene ◽  
Graphene Films ◽  
Transmission Electron ◽  
Zno Nanotubes ◽  
Metal Organic ◽  
Hybrid Configuration

AbstractWe report monolithic integration of indium arsenide (InAs) nanorods and zinc oxide (ZnO) nanotubes using a multilayer graphene film as a suspended substrate, and the fabrication of dual-wavelength photodetectors with the hybrid configuration of these materials. For the hybrid nanostructures, ZnO nanotubes and InAs nanorods were grown vertically on the top and bottom surfaces of the graphene films by metal-organic vapor-phase epitaxy and molecular beam epitaxy, respectively. The structural, optical, and electrical characteristics of the hybrid nanostructures were investigated using transmission electron microscopy, spectral photoresponse analysis, and current–voltage measurements. Furthermore, the hybrid nanostructures were used to fabricate dual-wavelength photodetectors sensitive to both ultraviolet and mid-infrared wavelengths.

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.

Parametrically Excited Electrostatic MEMS Cantilever Beam With Flexible Support

2016 ◽  
Vol 139 (2) ◽  
Author(s):  
Mark Pallay ◽  
Shahrzad Towfighian
Keyword(s):  
Cantilever Beam ◽  
Large Amplitude ◽  
Chaotic Behavior ◽  
Signal To Noise Ratio ◽  
Mass Sensors ◽  
Flexible Support ◽  
Sensing Applications ◽  
Electrostatic Mems ◽  
Fringe Fields ◽  
Steady State Amplitude

Parametric resonators that show large amplitude of vibration are highly desired for sensing applications. In this paper, a microelectromechanical system (MEMS) parametric resonator with a flexible support that uses electrostatic fringe fields to achieve resonance is introduced. The resonator shows a 50% increase in amplitude and a 50% decrease in threshold voltage compared with a fixed support cantilever model. The use of electrostatic fringe fields eliminates the risk of pull-in and allows for high amplitudes of vibration. We studied the effect of decreasing boundary stiffness on steady-state amplitude and found that below a threshold chaotic behavior can occur, which was verified by the information dimension of 0.59 and Poincaré maps. Hence, to achieve a large amplitude parametric resonator, the boundary stiffness should be decreased but should not go below a threshold when the chaotic response will appear. The resonator described in this paper uses a crab-leg spring attached to a cantilever beam to allow for both translation and rotation at the support. The presented study is useful in the design of mass sensors using parametric resonance (PR) to achieve large amplitude and signal-to-noise ratio.

Rapid Silicon-to-Steel Bonding via Inductive Heating

2006 ◽  
Author(s):  
Brian D. Sosnowchik ◽  
Liwei Lin ◽  
Albert P. Pisano
Keyword(s):  
Bonding Temperature ◽  
Surface Preparation ◽  
Fatigue Tests ◽  
Bonding Process ◽  
Inductive Heating ◽  
Sensor Applications ◽  
Mems Sensor ◽  
Sensing Applications ◽  
Minimal Damage ◽  
Point Bend

In this work, we present a rapid, low temperature process for the bonding of silicon to steel through the use of inductive heating for MEMS sensor applications. The bonding process takes as short as three seconds with a maximum bonding temperature as low as 230°C at the steel surface. The bonding strength is strong, and causes minimal damage to steel. The process has also been shown to work using leaded and leadfree bonding solder with minimal surface preparation to the steel. Four characterization experiments – tensile and compressive 4-point bend, axial extension, and fatigue tests – have been performed to validate the bonding process and materials. As such, this work illustrates the promise of applying inductive heating for the rapid silicon bonding to steel components for MEMS sensing applications.

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